The Mystery of the Galloping Horse

A KEN HOLT MYSTERY

By Bruce Campbell

CHAPTER I

ACROSS THE BORDER

The little traveling alarm clock said seven thirty. Through the window of the hotel room came the muted sounds of a city stirring into early-morning activity. Laredo, Texas, on the border between the United States and Mexico, was just coming alive.

But inside the hotel room there had been action for the past half-hour. Ken Holt and Sandy Allen were both showered and dressed, and Sandy's bag was already closed.

"You're sure you packed everything?" Ken ran a brush over black hair that was still damp and then tossed the brush into his own bag. He took a quick glance into the bathroom and stepped inside to pull two pairs of socks from a towel rack. "If we'd planned to leave these behind," he pointed out, "there was no sense in our washing them." Suddenly he bent over double, with an ease that spoke of steel muscles in top condition, and straightened again with a pair of slippers that had been under Sandy's bed. "You might need these in the next couple of weeks too," he remarked.

Sandy didn't respond. He was standing at the window, his massive, better-than-six-foot frame nearly blocking the glass. In the hard morning sunlight his red hair seemed afire.

"What are you looking at?" Ken demanded.

"Mexico." As Ken joined him, he gestured southward over low roof tops. "And feeling pretty let down about it," Sandy added. "It looks just like Texas to me."

Ken grinned up at him. "What did you expect? Acres of sombreros in full bloom?"

Sandy looked at him with disgust. Deliberately he took a small book from his shirt pocket, riffled through its pages, and then pronounced slowly, "Usted es loco." As he put the book away again he added loftily, "Since you don't share my great knowledge of Spanish, I will translate that for you. It means 'You are crazy.'"

"Yusted tambien," Ken retorted. "Which means 'And you too.'" He gave Sandy a brisk shove in the direction of their bags. "Come on. With Mexico just two blocks away, we're both crazy to be standing here instead of heading for the border."

"Right," Sandy agreed. "Especially since your father's expecting us to arrive in Mexico City eventually." He opened his bag, put in the socks and slippers Ken had found, and closed it again.

Ken snapped the locks on his own bag and then pulled a folded piece of paper from his pocket. "According to the list Dad left us, I think we're all set. We've got our tourist visas, we've got our vaccination certificates, we've changed some dollars into Mexican pesos, we've got Mexican insurance on the car-"

"Insurance!" Sandy broke in. "That reminds me." He took out his wallet. "Here's the bill for straightening and repainting our fender. We might as well send it home to Pop from here, so that he can forward it to the insurance company for payment." He glared down at the bill and shook his head. "Twenty-seven dollars- and two days' time-just because a dog didn't know enough not to run out into the middle of a Texas highway."

"Just because you can think fast enough to save a dog's life," Ken corrected him.

Sandy's face took on the red hue of his hair-an automatic response on his part to any hint of praise. "But your father had to catch a plane for Mexico City instead of being able to ride all the way down with us," he pointed out.

"What's worrying you?" Ken demanded. "Dad got there in time for his conference. Our car is as good as new again. And here we are at the border ourselves, all set for our first look at foreign territory. Are you afraid?"

"Afraid?" Sandy repeated in amazement. "What of?"

"Of starving to death. Maybe you think we won't be able to order enough food to keep you alive, if we have to talk Spanish."

Sandy ignored Ken's grin. "I am prepared to meet that emergency," he said, tapping the book in his pocket. He closed his big hand around the handle of his bag and swung it down from the luggage rack. "But speaking of food, what about breakfast?"

Ken picked up his own bag and led the way toward the door. "Why don't we wait until we cross the border?" he suggested. "We might as well find out right away whether your book is going to work or not."

"Suits me. Tortillas, enchiladas, tacos-here we come!"

"You don't even know what those words mean-except that they're things to eat," Ken reminded him.

"That's all I need to know," Sandy retorted.

A few minutes later, as they stood at the desk paying their bill, Sandy said, "I'll mail this car stuff to Pop. And why don't I wire the folks that we've reached the border?"

"Good idea," Ken agreed.

He joined Sandy at the telegraph counter when the bill was settled. As he watched his friend phrase the telegram he thought once more of the strange stroke of good fortune that had thrown him into the middle of the Allen family-the "folks" at Brentwood, New Jersey.

Ken, motherless since early childhood, had spent most of his life in boarding schools while his father, Richard Holt, traveled the world in search of the news stories that had made him the most famous foreign correspondent of Global News. Then there had come the time when Holt's nose for news made him dangerous to a band of criminals. They had kidnapped the newsman and were after Ken himself. And Ken, closely pursued, had taken refuge in the office of a small-town weekly newspaper, the Brentwood Advance. There he had found stanch allies in Pop Allen, the newspaper's editor, Pop's older son and assistant, Bert, and his younger son, Sandy. The three Allens, all redheaded and all over six feet in height, had joined Ken immediately in the adventure they still remembered as The Secret of Skeleton Island.

And when that adventure was over, tiny Mom Allen had joined her husband and her sons in insisting that Ken become one of their family. Since that time Ken and Sandy had been as close as brothers. They shared a room at the Allen house. They shared their work on the Advance, Ken supplying the stories and Sandy the accompanying photographs. Many of their assignments had led to excitement and danger. And on several occasions Global News had purchased Ken's stories and Sandy's pictures, reporting their adventures, for distribution through its nation-wide news service.

The trip to Mexico, however, was not expected to yield either news stories or news pictures. Richard Holt had been assigned to cover the Pan-American conference taking place in Mexico City, and it was his suggestion that the boys drive him to Mexico and join him, when the conference ended, for a three-week tour of the country. With Pop Allen's blessing, the boys had enthusiastically agreed. And the trip had been pleasant but entirely uneventful until the minor highway accident which forced Richard Holt to fly on ahead, while the boys remained for two days in the small Texas town where their car was being repaired. Now Ken and Sandy were on their way again toward the capital of Mexico, still some seven hundred miles to the south.

"Sound all right?" Sandy shoved the yellow telegram blank toward Ken.

"Headline for your front page," Sandy had scribbled. "Prominent Rrentwood citizens about to cross border into Mexico."

"Fine," Ken told him. "That'll provide a great scoop for the Advance"

Ten minutes later they were in the low, sleek red convertible that was their proudest joint possession. Their bags were neatly stowed away in the trunk and Sandy was maneuvering through the empty early-morning streets of Laredo toward the International Bridge that arched the muddy stream of the Rio Grande River.

The United States customs officer, at the north end of the bridge, waved them on after a quick check of their licenses and car registration. They paid the toll and drove on over the bridge.

"We've crossed the line!" Sandy exclaimed. "We're in Mexico."

"And here's your first chance to practice your Spanish." Ken pointed ahead toward the uniformed Mexican border official who was signaling them to halt.

Sandy braked the convertible to a stop and reached into the glove compartment for their tourist visas. He took a deep breath. "Senor," he began, "aqui-eh-aqui-“

The cheerful face under the trim uniform cap broke into a grin. "Perhaps," the border guard said in brisk English, "you would prefer to speak your own language."

The boys grinned back at him.

"I guess you'd prefer it," Sandy admitted. He glanced sidewise at Ken. "Maybe we'll go hungry after all."

"Don't worry," the Mexican assured him. "Most of the restaurants along the main highway have English-speaking waiters." Then he pointed off to the right of a large modern building. "Will you please pull around to that side and park your car?"

"Si, senor." Sandy looked at him questioningly. "That does mean 'Yes, sir,' doesn't it?"

The guard grinned once more. "Si, senor."

"Thanks."

The indicated parking space was entirely empty at this early hour. When Sandy slid the car to a stop again, under the overhanging roof of the building, another uniformed guard appeared immediately, followed by a porter.

"If you will give the porter all your luggage," the guard said, "he will take it inside for inspection. And you will then both come with me, please. Bring your tourist permits and the application for your car permit."

Ken and Sandy were traveling light. The porter had no difficulty with their two suitcases, a canvas duffel bag, and Sandy's camera case. As he walked off toward an open doorway the guard said politely, "You need not bother to lock your car. It will be watched while you are inside."

The border formalities were completed quickly and courteously. Less than ten minutes after the boys had entered the customs building their visas had been stamped and their car permit filled out, and they were waiting on one side of a long table on which their luggage had been arranged. The inspector, opposite them, rebuckled the straps of the camera case. Then he affixed seals to all the bags.

"Please do not break the seals immediately," he said. "You will pass two more customs stations. The first is seventeen miles south of here, the second some miles beyond that. If the seals are still in place, there will be no delay at those stations."

"Thank you."

"And now I will call a porter for your bags."

"Never mind," Sandy told him. "We can manage." He picked up the two valises as Ken took the duffel bag and camera case.

"I hope you will enjoy your visit to Mexico," the guard told them. "Just one word of warning, if I may," he added.

"Warning?" Sandy's eyebrows lifted.

"A Mexican hot sauce-it can be quite hot, senores."

Ken laughed. "Thanks. We'll remember."

"You don't scare me," Sandy said. "That's the first thing I intend to try."

The inspector shrugged cheerfully. "Well, don't say I didn't warn you."

Ken walked through the outer door ahead of Sandy and glanced back over his shoulder to see his friend examining a rack of colorful folders.

"Maps and stuff," Sandy called after him. "I'll pick up a few and be right out."

Ken nodded and continued toward the car. It was still the only vehicle parked beneath the overhanging roof. Beyond the block of shade under the roof the sun was already a white-hot glare. Ken squinted his eyes against it. He was within a few steps of the car before he saw the man standing alongside the convertible's left door.

Ken smiled automatically, assuming from the man's visored cap that he was another of the customs officials. But an instant later he realized his mistake. The man's cap was not part of a uniform. It was a fishing cap, worn at a rakish angle above well-fitted tan slacks and a matching sport shirt. The face beneath the visor was long and thin, like the man's body, and tanned to almost the shade of his clothes. The eyes were bright and watchful.

"Good morning," Ken said, as he moved around to the back of the car to open the trunk. The man probably was a tourist like themselves, Ken decided, and wondered vaguely where his car might be. He noticed only one other car in sight, a gray coupe. But it was parked a full hundred feet away from the customs building, and the swarthy, dark-haired man behind its wheel did not seem to be awaiting attention from the inspectors. He seemed, in fact, to be asleep. The eyes beneath the low forehead were apparently closed. Ken's idly curious glance traveled back from the gray coupe to the man who still stood beside the door of the red convertible.

"Morning," the stranger said then, quietly. And when Ken had stowed his burdens inside the car, he added, "Cigarette?"

"No, thanks. I don't smoke." Still curious, Ken wondered if the man was planning to cross the border on foot-or if, perhaps, he was leading up to a request for a ride with Sandy and himself.

The man fished a cigarette out of his shirt pocket and, without removing his strangely intent gaze from Ken's face, opened the lid of a silver lighter. A bright green flame leaped into life above the metal case.

Ken's eyes widened involuntarily. "Tricky," he commented. "What makes the green color-a special fuel?"

The intent gaze narrowed slightly. "You shouldn't leave your car unlocked like this," the man said, ignoring Ken's question.

"Why not? The guard told us it would be safe. Besides, all our luggage was with us inside the building. There was nothing here to steal." The stranger's attitude annoyed him.

"Nothing?" The quiet voice repeated a single word out of Ken's reply, giving it the rising inflection of a question.

Ken frowned. "That's right. Nothing."

The man blew a cloud of smoke into the still air. "All right. I guess you're trying to play it safe." He flicked his cigarette away. "But you can relax now. Just give me the keys and we'll get moving."

Ken stared at him blankly. Then he said, "Look, there must be some mistake. You must have us mixed up with some other party. We don't need a guide."

"We?" Suddenly the quiet voice sharpened. "Who's with you? Just because you're across the border, don't think that-"

"Don't think what?" Sandy had arrived unnoticed and dropped the two bags on the ground with a thump. "What's up, Ken?"

Ken signed with relief. Now that Sandy had joined him they could leave. "Nothing," he assured Sandy. "This gentleman here just had us confused with someone else."

As he spoke, another car swung around the corner of the building from the direction of the International Bridge. It, too, was a convertible. And it, too, was red. It pulled to a stop and the driver looked expectantly around, as if seeking something. His neat dark business suit seemed out of place in the bright Mexican sunshine, and the pallor of his face was accentuated by dark glasses.

The horn of the gray coupe", parked some distance away, sounded loudly, twice.

As Ken heard the signallike toots he saw the man with the green-flamed lighter swing sharply around and focus his eyes on the new arrival. When he turned back toward the boys he was smiling for the first time.

"You were right," he said. "I guess that's the party I was supposed to meet." His hand gestured a brief salute in the air as he walked briskly toward the second convertible.

"Now that that slight confusion has been cleared up, let's go." Sandy swung the two bags up into the trunk and banged the lid down decisively.

"Wait a minute." Ken spoke quietly. "I can tell you exactly what's going to happen. Our friend is going to offer a cigarette to the man in the convertible, then he's going to light it with a lighter that has a green flame."

The flame glowed green for an instant.

"A green flame?" Sandy stared at him with mock concern. "Has this foreign air affected your mind?"

"Just watch," Ken told him. "There! What did I tell you?"

In the shade beneath the customs building roof the little flame glowed green as an emerald for an instant as two cigarettes were lighted. Then the flame flicked off and the two men shook hands.

"O.K.," Sandy said. "You were right. And very impressive, mastermind. But do you mind saving your next trick until after we've had breakfast?"

The owner of the green-flamed lighter was approaching them again. "I just wanted to apologize," he said. His tanned face creased in a smile. "Sorry I took up your time and all. Anything I can do in exchange? I know this country pretty well. Maybe I could be of some help. Where are you heading for?"

"Mexico City," Ken told him briefly.

"In that case you don't need any help," the man assured them. "The road is fine all the way, with plenty of good places to stop and some fine restaurants. As long as you stay on the main highway, you won't have any trouble. And if you'll take the advice of a man who's traveled these roads for years, that's what you'll do. It's the side roads around here that are likely to be bad-and dangerous." For the second time he raised his hand in good-by. "Maybe we'll be seeing you along the road." He walked back toward the second red convertible with long, easy strides.

"Who asked for his advice?" Sandy muttered. "Who said anything about getting off the main highway?"

"He did-himself," Ken said thoughtfully. "And he made it sound more like a warning than a piece of friendly advice!"

CHAPTER II

CURIOUS HITCHHIKER

Sandy looked fixedly at Ken for a moment and then he shrugged his shoulders. "Oh, well, who cares?" he asked. "Warning or advice-what difference does it make? We're not going to leave the main highway in any case, so who cares whether the side roads are good or bad?"

Ken shook his head skeptically. "I don't think he was referring to the condition of the roads."

Sandy had already slid beneath the steering wheel and Ken got in beside him. But as he closed the door and settled himself, while Sandy guided the car around the corner of the customs building toward the highway beyond, Ken kept his eye on the second red convertible. The man with the green-flamed lighter and the driver of the convertible were still in earnest conversation.

"The green flame on that lighter is certainly some kind of a recognition signal," Ken said, half to himself. "But why?"

"Why what?" Sandy demanded.

"Why all the cloak-and-dagger stuff? When grown men go around using secret signals to each other, they're usually up to no good."

"If you really want to worry about something, start worrying about signs, will you?" Sandy said impatiently. He pointed to the lettered placards posted at the junction of the main highway just ahead.

"Alto," Ken pronounced obediently. "That obviously means halt-stop. This must be a stop street." Then he stared at the one below it, which read Velocidad Maxima 30 Km. "Maximum velocity-in other words, speed limit-thirty kilometers." Ken did rapid mental arithmetic. "A kilometer is about five-eighths of a mile, so thirty kilometers is about nineteen miles an hour. O.K.?"

"O.K." Sandy began to swing the car carefully into the main road. But he had not completed the turn when he stopped. A young man standing at the highway intersection was signaling him with a raised hand. Immediately the stranger stepped close to the car and rested an arm on Ken's door. He was tall enough so that he had to bend down to peer in at the boys, and his face was square and cheerful. A small canvas weekend bag dangled from one arm and he was wearing serviceable slacks, sport shirt, and light windbreaker.

"Hi," he said easily, before either of the boys had a chance to speak. "Saw your car parked at the customs building and figured maybe Mexico City was your destination. If it is-or if you're going at least part of the way along the main road-how about a lift?"

He was quick to catch the glance that passed between the two boys, and he added rapidly, "Guess I should have introduced myself before I started asking favors. My name's Mort Phillips, and I'm a United States citizen studying at the University of Mexico." He had pulled a wallet out of his pocket and opened it now to disclose an identity card and driver's license.

Then from a pocket in his windbreaker he drew a folded piece of paper. "My new tourist visa," he explained. "I have to come up here to the border to renew it every six months." Thrusting the wallet and visa both through the car window, so that Sandy too could see them closely, he added, "All aboveboard."

"We're not doubting your word," Sandy said. "We-"

"It's always a good idea to play safe and check up on people," Phillips assured him. "I probably could make myself useful," he added. "I know the road and the language. Well-what do you say?"

Again the boys looked at each other. They had no particular desire for a third passenger in the car. But, on the other hand, there seemed no valid reason to refuse Phillips' request, and he appeared likable enough in a brash, cheerful way.

Ken turned toward the expectant face in the window. "Sure, come on," he said. "You might as well dump your bag on the back seat and sit up front with us."

"Swell. Thanks." The square face split in a grin.

The boys introduced themselves as Phillips slung his light bag into the car and then slid in beside Ken.

"Holt," Phillips repeated, when he heard Ken's name. "Sounds familiar, somehow. Isn't there a famous newspaper reporter named Holt?"

"Sure," Sandy told him. "Richard Holt-Ken's father."

"Oh!" Phillips eyed Ken with new interest. "But wait a minute. Holt and Allen-that rings a bell too. Wasn't there something in the papers about some water-front thugs tangling with-" He broke off abruptly. "Of course! That was you two. I remember now. The Mystery of the Galloping Horse, the papers called it. And the thugs came off second best."

"We were just lucky," Ken told him. Phillips' open-eyed admiration made both him and Sandy feel uncomfortable.

"Oh, sure." Phillips laughed in disbelief. "Well, I certainly feel lucky, all right. Lots of people don't understand that a hitchhiker takes a real chance when he gets a lift with strangers, but now I know I'm in good hands."

Deliberately Ken changed the subject. "Don't forget we want to stop for breakfast before we get out of town, Sandy."

"Just what I was remembering," Sandy told him quickly.

"Great!" Phillips said. "I was just going to ask if you'd mind my dropping off one minute to say good-by to a friend. And he's at a restaurant right near here, so that all works out fine. Just take the next turn to the right-that's it, that one."

Ken could sense Sandy's resigned shrug beyond the husky pair of shoulders that intervened between them. Phillips, he was thinking, certainly didn't mind taking things into his own hands. But there was no obvious excuse for failing to accept his suggestion, since neither he nor Sandy knew of a restaurant in Nuevo Laredo, the tourist-crowded town just south of the Rio Grande.

Sandy made the right turn, into a slightly narrower street. Like the main thoroughfare they had just left, it also was crowded with souvenir shops of all kinds. Every shopwindow was bright with colorful Mexican pottery, wide-brimmed sombreros, and a variety of other typical articles designed to attract the visitor's eye.

"Park right up there-near the corner," Phillips directed.

Sandy pulled into the open space lie had pointed out, directly behind a black sedan, a big, heavy American car, distinctive because of the whip antenna fastened to its rear bumper.

Phillips led the way into the small restaurant across the narrow sidewalk. Its walls were gay with posters advertising soft drinks, but the room itself was deserted, all six of its small tables empty.

"Was your friend supposed to be here?" Ken asked, as he and Sandy pulled out chairs for themselves.

Phillips didn't answer. He was grinning a greeting to the short, stout man who had just entered the room through a rear door. Plump hands were hastily tying a white apron taut across a round stomach.

"Buenos dias, sefior," the man was saying. "You are very hungry today, no?"

Phillips spoke to him in Spanish so rapid that the boys couldn't catch a single familiar word. The restaurant proprietor answered with a similar torrent.

Phillips nodded his understanding and turned to the boys. "My friend has just gone across the street to get some cigarettes. Let's order first-and then I'll run over and say good-by to him. I can recommend the huevos rancheros here," he added, seating himself between them. "Eggs ranch style, that is," he explained. "A Mexican specialty."

"Hot?" Sandy inquired, his interest in food overcoming his mild irritation at Phillips.

"Hot or mild-any way you want them," Phillips assured him.

"Good." Sandy squared his shoulders. "I'll take mine hot."

"I'm going to train my palate gradually," Ken said. "I'll take mine fairly mild."

"And how about some orange juice first?" Phillips suggested. "And some rolls and coffee?"

When the boys nodded, he relayed their orders to the proprietor in Spanish. Then, as soon as the stout man trotted off, Phillips got to his feet. "And now if you'll excuse me for a moment-be right back." He headed briskly for the front door.

Ken got up a moment later to walk more slowly toward the front of the restaurant. Through the Venetian blind hung in the window, its slats tilted down to keep out the morning sun, he peered into the street.

"What's eating you now?" Sandy asked.

Ken turned his head and spoke quietly. "Phillips' friend isn't across the street buying cigarettes," he said. "He's sitting in that big black sedan parked in front of our car. I noticed that there was somebody in the car as we came by, and Phillips must have noticed him too. But he didn't say a word then." He leaned forward slightly. "Now both of them are disappearing around the corner-on foot."

"So what?" Sandy asked. "I didn't notice anybody in that car. Maybe he didn't either." Idly he fingered the bottle of hot sauce standing between the sugar bowl and the salt shaker. "But I am a little sorry we picked him up. He-"

The arrival of their orange juice, delivered by the beaming proprietor, put an end to his comments. And there was no chance to continue them again because Phillips returned just as the proprietor left the room.

"How is everything?" he asked with his usual cheerfulness.

"The orange juice is good. That's all I can vouch for so far," Sandy told him.

"I'd be surprised if it weren't. Mexico's got some wonderful orange groves. You'll see some along the highway later today." Phillips too drained his glass appreciatively.

A moment later the proprietor returned with three platters of eggs drenched with a reddish-colored sauce. He set one before Phillips and then hesitated a moment.

Phillips pointed to Sandy. "Con salsa picante." He grinned as the third platter was put before Ken. "Yours," he explained, "is not so picante."

A moment later the proprietor was back with a pitcher of jet-black coffee and a pitcher of hot milk. He poured coffee into Phillips' cup until it was half full and then added milk until the liquid neared the brim. Sandy's cup was filled the same way. When he approached Ken, obviously preparing to repeat the performance, Ken said firmly, "I'll take mine black."

The proprietor frowned. "But it is very strong, senor."

"That's all right. I like strong coffee," Ken assured him.

Phillips shot him a quizzical glance but said nothing.

The proprietor filled Ken's cup only about two-thirds full, and then put the pitcher of milk on the table. "I leave this here, senor," he said. "I think perhaps you change your mind."

Sandy was poking at the thin grayish wafer he had discovered beneath his eggs. "What's this? A pancake?"

"A tortilla," Phillips said. "Made of corn, you know. A real staple down here. Sometimes they fry it crisp, and then it's called a taco. Sometimes . . ."

Ken had taken his first bite of eggs and found them delicious. The lightly spiced sauce poured over them, he decided, was a fine addition. And the crusty roll he broke open was hot and light. He found himself suddenly less annoyed at Phillips than he had been.

It occurred to him that his irritation might have grown out of nothing more real than hunger.

Sandy was smiling too. "You should have had yours hot too, Ken," he said. "This sauce is great. It-" He stopped suddenly and a startled expression flashed over his features. Then his face flamed red and tears brimmed in his eyes. "Water!" he gasped. His hand clutched his throat. "Water-quick!"

Phillips was looking amused, but he spoke swiftly. "No-eat this." He thrust a roll into Sandy's hand. ''Water doesn't drown out this hot sauce," he explained to Ken, as Sandy bit off a huge bite of the roll. "Bread -plenty of it-is the only thing."

Ken, aware now of the source of Sandy's agonized look, grinned in spite of himself. "Let this be a lesson to you," he told his friend as he picked up his coffee cup. "Next time maybe you'll have a little more respect for-" He paused to take a swallow of the black brew in his cup. The next moment his whole face twisted into a grimace, an involuntary reaction to its bitterness.

Sandy, eyes still streaming, spoke around a mouthful of his second roll. "Laugh at me, will you?" he demanded.

"I guess we've both got something to learn." Ken poured milk into his cup, tasted again, and then added still more milk. Before he was satisfied, his cup too was at least half full of milk.

"Don't let this get you down," Phillips said cheerfully. "You have to get used to these hot sauces gradually. And drinking this kind of coffee black-well, I never could get used to that." Sandy watched admiringly as Phillips calmly swallowed a mouthful of what, he assured the boys, was a sauce equally as hot as that on Sandy's plate. "But let's get you another order," Phillips added, calling the proprietor. "You can't travel on an empty stomach."

A moment later, when Sandy's plate had been removed, Phillips said, "You know, I envy you coming into Mexico for the first time. It's a great place. That is-this is your first trip, isn't it? What brings you down here?"

Sandy explained briefly about the conference in Mexico City and the vacation which the boys expected to enjoy at its conclusion with Richard Holt. His eggs, less highly seasoned this time, arrived while he was talking. Sandy tackled them hungrily and without any ill effects.

Phillips nodded. "Sounds wonderful. And you can see a lot in three weeks. But get off on some of the side roads. Most visitors are afraid to do that, and I think it's a mistake."

Sandy glanced at Ken. "See? Here's somebody who doesn't agree with your green-flame friend."

"Who is it I don't agree with?" Phillips asked.

"Some man back at the customs house," Sandy explained, "who took us for somebody else. I guess he was a guide or something like that. But then another red convertible came in and he realized he'd made a mistake."

Phillips was casually breaking a roll into small pieces, but there was a sudden sharpness in his voice that caught Ken's attention as he asked, "And what is it we don't agree about?"

"He said we should stick to the main roads," Sandy explained. "Said the side roads might be dangerous. Ken thought it was some kind of mysterious warning."

Sandy was eating too busily to notice the curious change in Phillips' attitude, but Ken was very aware of it.

"Why?" Phillips asked. "A warning against what?"

"Ken gets that way sometimes," Sandy said, grinning across the table at his friend. "He suddenly gets a hunch that somebody is a sinister character. Just because this man had a cigarette lighter with a green flame, he thought he was signaling somebody."

"Hmm. Does sound curious. Must admit I never saw a lighter with a green flame-but then there must be lots of things I haven't seen."

Phillips was making, Ken felt sure, a deliberate effort to sound casual. He found himself wondering about the man's curiosity, and wondering even more about his apparent efforts to conceal it.

A moment later Phillips swallowed the last of his coffee and looked around the table. "Whenever you two are finished," he said, "I'm ready to start. In the meantime, I'll take care of the bill." And when Ken automatically protested, he said, "No, I insist. The least I can do in return for the lift is to buy your first Mexican meal." He summoned the proprietor then and paid the check, while Ken and Sandy drained their own cups.

"He's in a hurry all of a sudden," Ken found himself thinking, and again he wondered.

As they climbed into the convertible a moment later Ken noticed that the big black sedan was gone. And the open highway, when they left Nuevo Laredo behind, seemed occupied almost entirely by crowded buses and trucks. Ken, who was driving, instinctively watched for another red convertible, although he reminded himself that it probably was fifty miles ahead by now, unless its occupants too had stopped for breakfast.

The country was flat and dull, with a sparse cover of low bushes. Villages were few and small, each one little more than a handful of low earth-colored houses made of sun-baked adobe brick.

"I still feel let down," Sandy muttered. "It still looks just like Texas."

"There isn't much to look at until you get near Monterrey," Phillips agreed. "Then the hills begin and the road is more interesting. In the meantime, if you don't mind, I'll practice some Spanish verb conjugations. I've got an exam coming up when I get back to school." He took a small notebook from his pocket and settled back into the corner near the door.

Ken's foot pressed down on the accelerator. Ten minutes went by, and as many miles. Suddenly a highway sign loomed up on the right.

Phillips roused himself. "Despotic," he read, and translated the word. "Slow down. The first customs station is right ahead."

The small building appeared a moment later, and a man in a neat brown uniform waved them to a halt beneath a portico that offered protection from the hot sun.

"Will you please show me your tourist permits and your car permit," he said politely. "And unlock the trunk of your car."

They all handed over their papers. While the guard took them, Phillips opened the door and got out. "Want me to unlock the trunk?" he asked.

"Never mind, thanks. I'll do it." Ken opened the door on his side of the car and walked around to the trunk. Phillips, he noticed, sauntered toward the small customs building where a man in civilian clothes stood leaning against the wall. Phillips spoke to him quietly and the man answered in a voice equally inaudible.

"Having trouble?" Sandy joined Ken.

Ken shook his head. "Just a little curious about our hitchhiking friend." Without taking his eyes off Phillips he fumbled around for the lock and inserted the key.

Phillips still had his small notebook in his hand, and now he was tearing out a page and folding it over, as if absent-mindedly unaware of what he was doing. But suddenly, in a single swift movement, the folded paper changed hands and disappeared into the stranger's pocket.

"Did you see that?" Ken murmured. The customs official was coming toward them and he hastily flung up the lid of the trunk.

Over the official's head Sandy nodded. There was a puzzled look in his eyes.

The official glanced inside the trunk and nodded his satisfaction when he saw that the seals put on at the border were still unbroken. "Thank you, senores. You may close it now."

Phillips wandered back to the car. "Just been checking up," he said. "When I came north recently there was a road gang at work on the highway not far south of here-delayed me half an hour. But I've been told the work's all done and the road is clear now."

Ken and Sandy looked at each other. If Phillips and the stranger had been discussing road conditions, what reason would there have been for the swift passage of a note between them?

CHAPTER III

CHANGED PLANS

Phillips appeared not to notice the look the boys exchanged. While Ken banged down the trunk lid, Phillips rattled off a volley of Spanish at the customs official. The official's answer, a quiet, "No, senor," threw no light on what Phillips had said.

Then the official was returning their identification papers, bowing slightly, and saying, "Thank you, senores. That is all. But please do not break the seals until you pass the next inspection post about a hundred and fifty kilometers farther on."

As they all climbed back into the car Sandy raised his eyebrows at Ken, silently querying, "What do you make of it?"

Ken shook his head. He was remembering that Phillips had pretended not to see the man he later conferred with, back at the restaurant, and that he had shown definite interest in Sandy's account of the man with the green-flamed lighter. Now, for some reason, he had secretly passed a message to the stranger leaning against the customs-house wall. Ken glanced over toward the little building. The man to whom Phillips had handed the folded slip of paper was no longer in sight.

Ken couldn't have answered Sandy's question in words, even if he had had the opportunity, but he had the definite feeling that Phillips was not what he claimed himself to be.

"All set?" Their passenger spoke as cheerfully as ever.

"Sure," Ken answered shortly. A moment later he swung the car back onto the road that stretched flat and straight ahead of them, under the blinding sun.

Far to their right, dimly visible through a faint haze, a range of mountains seemed to parallel their course. But as mile after mile flowed away beneath their wheels, the rugged hills drew a little closer. The country remained only sparsely populated, however, and it was a relief, some thirty miles beyond the inspection station, when the highway ran through the little village of La Gloria. It was upon them suddenly. Ken slowed the car. On either side of the road, cement and whitewashed adobe houses stood in closely packed rows. Each house adjoined its neighbor, creating a single unbroken front wall close to the highway's edge.

Phillips broke a long silence. "Try to catch a glimpse through an open doorway," he said. "Houses like this look pretty grim to those of us who are accustomed to front and back yards. The barred windows and the heavy doors and solid walls don't look very cheerful to us."

A procession of six burros, each laden with two cumbersome bags of charcoal, appeared suddenly at the intersection of a narrow cobblestoned cross street. Ken braked to a stop when it was apparent that they were going to amble slowly right across the highway.

"There-to the right-look!" Phillips said, gesturing toward an open doorway. "You can't have any idea of how Mexicans live until you know about the patio in the center of almost every house."

The boys looked in the direction toward which he was pointing. Almost opposite the car a heavily timbered house door stood open, and beyond it, at the far end of a short corridor, was a brilliant riot of lush-green leaves and many-colored flowers. Its vivid contrast to the sober quiet of the street was breath-taking.

"The patio down here represents a whole way of life," Phillips was saying. "It permits the people to live most of their lives outdoors, but with complete privacy. Of course not every patio is that beautiful. Some of them are pretty well crowded with chickens and pigs and other kinds of livestock. But almost all of them have gardens and flowers of a sort."

The last burro had crossed to the far side of the highway. Almost reluctantly Ken turned his head away from the flower-filled patio and started the car again. The Mexican owner of the burros touched his wide-brimmed straw sombrero with a gesture of thanks as he followed his animals, and the car began to move slowly forward.

Ken gestured a response to the Mexican's thanks, and Phillips too waved a hand.

"Almost everybody you'll meet down here will be polite," he commented. "I think you're going to like the Mexicans. They're dignified and friendly and- well, just nice people."

Ken glanced sideways at him with curiosity. There had been a genuine warmth in Phillips' voice, an honest admiration for the people of the country. Was it really likely, Ken asked himself, that a person so openly friendly, as Phillips appeared to be, would involve himself in some dark and mysterious undertaking?

A block farther on, the highway formed one boundary of the village square, a place of tree-shaded walks and beds of flowers.

"Drive around the square if you can take the time," Phillips said, and Ken found himself swinging obediently to the right.

"If this were market day in the village, the whole plaza would be occupied with tiny stands-some of them no more than a piece of cloth spread out on the sidewalk," Phillips was saying. "Weekly market day is a wonderful institution down here. You must try to see at least a couple while you're in the country. People come from miles around, to buy and sell and just to visit. It's a great sight-pottery, shoes, vegetables, flowers, scrapes, and rebozos-all spread out so close together you can hardly walk between them."

A group of sturdy boys playing in the square, all dressed in jeans, grinned and shouted, " 'Allol"

" 'Allo!" Phillips called back, and Ken and Sandy waved.

"Those kids are dressed the same way kids dress in the States," Sandy commented.

"Sure. And they've got television and refrigerators and movies down here too, just like ours," Phillips said.

"And juke boxes," Ken added, pointing to a huge one set up under an awning at the small refreshment stand which occupied the corner at which their circuit of the plaza ended.

As the car turned back into the highway again, Phillips said, "I guess I've been talking like a travel guide. But I'm so crazy about this place I want everybody else to like it too. That's why I was urging you to get off the main road if you can, so that you'll see something besides juke boxes and the trucks and buses on the highway. The real Mexico is off the road, in the little villages that aren't crowded with tourists."

Beyond La Gloria they crossed the Salado River, a small trickle of water at the bottom of a ravine. The highway was beginning to change its character. It was no longer ruler-straight, although Ken still found it easy to maintain a sixty-mile-an-hour pace. Most of the traffic they encountered consisted, as it had earlier, of trucks and heavily laden buses-and innumerable burros. Some of the patient long-eared animals were carrying loads and plodding along the road's edge at a steady pace. Others were cropping the sparse grass on the shoulder, apparently-like their masters, sometimes glimpsed in the thin shade of a bush-enjoying a brief rest.

Twenty miles below La Gloria, as they approached the village of Vallecillo, Sandy said, "I could do with a cold drink, Ken. That looks like a roadside stand coming up."

Ken was so accustomed to Sandy's regular suggestions of food and drink that he offered no argument. Almost automatically he pulled up in front of the tiny gaily painted stand not far ahead.

"Good idea," Phillips was saying. "I'll get them." He jumped out of the car and headed for the counter, which was tended by a young boy with black hair and lively black eyes.

Sandy leaned close to Ken and spoke in a low voice. "I'm not really dying of thirst," he murmured. "I just wanted a chance to talk for a minute. I've been thinking about this Phillips guy and it seems to me it would be a good idea if we eased him out of our lives. Why don't we tell him we're not going straight through to Mexico City after all-that we've decided to stop over in Monterrey? I've got a hunch that if he sticks with us we'll somehow land in the middle of some strange goings on."

"So you've got a hunch now," Ken said dryly.

"I'm serious," Sandy whispered urgently. "He seems nice all right, most of the time-but some of his behavior has been pretty peculiar."

"I know." Ken nodded. "I can't figure him out. Maybe he's somehow tied up with that green-flame lighter routine. Or maybe he's-"

"Whatever he's up to, I say we'd better count ourselves out of it," Sandy broke in. "We're down here on a vacation. We don't want to get mixed up in anything-and I mean ant/thing."

"I'd kind of like to find out what's going on, though," Ken admitted. "And if we drop him, we never will."

"If we don't drop him, and get involved in some mix-up, your father is going to be pretty annoyed when we don't turn up in Mexico City," Sandy pointed out.

Phillips was returning to the car, holding three bottles of soda glistening with drops of moisture. Ken bit off his answer.

Phillips stood outside the car as he drank, tilting the bottle against his lips. But in the middle of his first long swallow he lowered the bottle abruptly and stood staring up the road, in the direction from which they had just come. The boys instinctively twisted their heads to follow his glance.

The second red convertible was tearing toward them. And directly in its path was one of the inevitable small processions of burros, half a dozen animals ambling

Directly in its path was a procession of burros moving slowly across the highway. The horn of the oncoming car blasted raucously, but the animals continued their slow, oblivious movement.

At the last possible moment the red car came to a screaming stop, its locked wheels skidding on the smooth roadway.

Five hundred feet behind it another car was slowing down, and neither Ken nor Sandy had any difficulty in recognizing the car that had been parked in front of the Nuevo Laredo restaurant earlier that morning. Its rear whip antenna waved wildly as the heavy vehicle bucked against hastily applied brakes.

Then the burros stepped onto the shoulder at the far side of the highway and the red car started up again with a jerk. The man with the green-flamed lighter was at the wheel as it sped past the roadside stand. The car's original driver sat slumped low in the seat beside him.

The black sedan followed, but at a considerably slower speed.

Ken glanced quickly toward Phillips and realized only then that their passenger had stepped back into the shelter of the refreshment stand's overhanging awning. He stood half-turned away from the highway, his face almost entirely invisible. But Ken could see that the hand that clutched the soda bottle held it so tightly that the knuckles showed white.

As Ken watched him curiously, Phillips straightened up and began to step forth from his place of near-concealment. But after a single step he stopped and retreated once more.

Another car was coming along the highway and an instant later it zipped past in a flash. This one, too, the boys had seen earlier. It was the gray coupe that had been parked some distance away from the customs office at the Laredo border station.

Ken wasn't aware that Phillips had moved, but suddenly he was standing close to the highway, his eyes riveted on the rapidly disappearing car. His lips moved slightly, as if he were repeating something to himself.

Ken spoke his deduction half-aloud. "He's memorizing the license number."

Sandy had no time to comment. Now Phillips was striding toward them, his face set, his eyes narrowed. For an instant he seemed entirely different from the man who had, so recently, talked to them warmly of Mexico and Mexicans. But even as Ken became aware of this difference, it disappeared. By the time Phillips reached the car, and leaned easily on the door next to Ken, the grimness had gone from his features. All that remained was a look of mild irritation, coupled with a slight embarrassment.

"I'm afraid my temper flares up," he said easily, "every time I see fools driving through a village as if they were on a race track. I always take down their license number, but by the time I've found a policeman to report to, my temper has died down and I don't do anything about it." He grinned and finished the contents of his soda bottle in one long swallow. "All set?" He eyed Ken's bottle and Sandy's, still both nearly full.

Ken had come to a decision. He knew Sandy was right. Richard Holt was expecting them in Mexico City, and they had no right to expose themselves to any situation, however curious, that might delay their arrival. He wondered if he would ever learn the significance of the signal that was transmitted with the green flame on a cigarette lighter, but he told himself that this time his curiosity would have to go unsatisfied.

"We've been thinking," he told Phillips, "that we'd like to stop over in Monterrey for a while, to take a look around. So if you're in a hurry to get on to Mexico City, maybe you'd rather leave us behind and look for a ride with somebody else."

"Oh." Phillips looked at him sharply. "I thought you were in a hurry to get there yourself."

There was relief in Sandy's voice as he said, "Well, we are, of course. But a day or so won't make much difference. Ken's father will be tied up all week, anyway. And it seems silly to go dashing through the country so fast that we don't have a chance to look around. Monterrey's worth looking at, isn't it?"

"Oh, yes. Very much." Phillips was still eying them intently and his voice sounded almost absent-minded, as if he were thinking of something else. "Big factories, mostly. People call it the Pittsburgh of Mexico." He straightened up suddenly and backed away from the door. "In that case," he said, "if I'm going to be looking for another ride in Monterrey, I'd better make a phone call if you don't mind waiting a minute. I've got an appointment in Mexico City tomorrow, which I may not be able to keep now."

"We're sorry," Sandy said awkwardly, "if this-"

"No-not at all." Phillips grinned his cheerful grin. "Glad you're really going to take enough time to see this country."

There was a public telephone on the inner wall of the little refreshment stand and a moment later Phillips was rattling Spanish into it.

"We could have said we'd leave him right here," Sandy muttered.

Ken didn't answer. Instead he said, "Three cars in a row-red, black, and gray. Who's following whom? And how does Phillips fit into the picture?"

Sandy jabbed him in the ribs with a sharp elbow. "Answers to both questions," he pointed out, "are none of our business."

"I suppose not. But-"

Phillips was coming back toward them. "It'll take too long to get my call through. I'll make it from Monterrey." Despite his easy manner he seemed restive and anxious to get started. "You finished now?"

Ken and Sandy handed him their empty bottles and a couple of peso notes. And then they were on their way again, traveling once more in the silence that had marked the first part of the trip.

Vallecillo fell behind them and, some fifteen minutes later, the sizable town of Sabinas Hidalgo. And beyond Sabinas Hidalgo the road finally began to climb and twist up into the mountains.

Phillips glanced down at his watch. The time was shortly after eleven. "We're crossing a spur of the mountains we've been seeing on our right," he said. His tone was casually informative, but he was leaning forward slightly, as if to urge the car ahead.

But now the road switched back on itself every few hundred feet, in hairpin turns, and the speedometer reading dropped down below thirty miles an hour. Ken rounded a sharp corner and found himself behind a heavy Diesel truck, belching black smoke as its engine labored. The truck was crawling upward at scarcely more than five miles an hour.

The smoke billowed around them. Ken edged out to the left to pass the big vehicle, but ducked back in line when he saw another turn directly ahead. Beyond that turn he tried it again, but once more the glimpse of a sharp corner a few hundred feet beyond the truck forced him to fall back.

"Toot your horn," Phillips said impatiently. "Then the truck driver will let you know if you can pass." He laughed suddenly and apologetically. "Sorry. Didn't mean to tell you how to drive your car."

"That's O.K." Ken tapped the horn twice. Almost immediately the taillights of the truck blinked.

"He's telling you the road's clear," Phillips said.

Ken stepped down hard and swung to the left. As he raced past the cab of the truck, the driver waved them cheerfully on.

There seemed to be no end to the turns or to the climbing. Each sharp curve seemed to bring them within sight of the crest of the pass, but beyond that turn the road was always still climbing further. Far below them they could sometimes catch glimpses of the twisted thread of road they had come over. Once they saw the Diesel truck still laboring forward, miles behind them now, like some sluggish insect inching its way upward.

And then, suddenly, they did reach the top of the pass. The road leveled off for several hundred feet, then began to drop as rapidly as it had climbed.

Ken was pumping his brake pedal around a particularly sharp curve, about a mile below the summit, when Phillips shouted:

"Stop! Look there! Somebody went over the edge! Stop!"

They were a hundred feet beyond the skid marks before Ken could bring the convertible to a halt. The tire marks ran straight toward the outer edge of the road and across the shoulder that ended at the lip of a sharp drop downward. The guardrail at that place on the shoulder had been ripped away.

Phillips was out of the car even before Ken could pull the hand brake up and kill the engine. The boys tumbled out after him in time to see him disappear over the edge at the place where the rail was broken. When they, too, reached that place they could see Phillips some distance below the level of the road, plunging down the steep slope in flying leaps. He was already halfway down toward the black sedan, which lay on the slope on its side. The thick clump of brush, against which the overturned car rested, had obviously prevented it from crashing clear to the bottom of the canyon, several thousand feet below.

Ken and Sandy hesitated only a moment. Then they started down the slope, digging their heels into the ground at every plunging step to keep themselves from sliding downward in an uncontrollable rush.

Below them, Phillips reached the sedan, landing beside it in a cloud of dust. They could barely see his figure as he peered downward through the windows. As the boys landed at his side he looked up and around.

"Ramon!" he called sharply. "Ramonl"

"Si! Si! Coming. I am here." A figure was crawling slowly toward them from the far side of the brush-a small compact figure of a man with torn clothes and a bleeding face.

Phillips moved swiftly in his direction. "You all right?"

"Yes, Mort." The man spoke English with a marked Spanish accent. "Just bruised and scratched." He grinned, and his teeth were startlingly white in his swarthy face. "And very lucky."

"When I didn't see any sign of you," Phillips said, "I—“

The Mexican smiled again. "I was-how do you say? -playing possum. In case our friends returned to-" His glance fell on the boys and he broke off abruptly. "But I can give you the details later, no?"

Phillips nodded. "As long as you can walk-"

"Perfectly. And with a little soap and water I shall be nearly as good as new."

"Fine! Then let's get going."

Ken took a deep breath. He had immediately recognized the man Phillips called Ramon. He was the "friend" with whom Phillips had mysteriously conferred while they ate breakfast in Nuevo Laredo, and the big black sedan was the antenna-equipped car which had been parked in front of their own convertible. Phillips must have known that the black car was traveling south along the highway-and yet he had asked the boys if he might ride with them.

"Wait a minute," Ken said, as Phillips took his first step back up the steep slope. "How do you plan to travel -from here on?"

Phillips looked at him sharply. "I assumed I could remain your passenger as far as Monterrey," he said. "And I took for granted you'd play good Samaritan to a friend of mine who's been in an accident. We've both got good reason to want to get to Monterrey in a hurry. So let's get started-if you've got no objection."

"I think we have," Ken said slowly. "If your friend had been seriously hurt, we couldn't do this, of course. But he insists he's all right, so-well, I think we'll bow out here. I gather he was forced off the road. We'd just as soon that didn't happen to our car, because he was riding with us. Maybe that big truck coming along behind will pick you up. Come on, Sandy."

Together, he and Sandy turned and started back up the hillside. They had taken only a few steps on the steep slippery slope when Phillips' voice spoke.

"Wait!" The single word barked out on a note of sharp, decisive command.

Ken took another step upward, but he glanced back over his shoulder-and froze.

"I can understand your wanting to get away from something that doesn't concern you," Phillips was saying levelly, "but we need you for a little while longer. And I'm afraid we're going to have to insist upon your co-operation."

The words were hardly necessary. It was the heavy automatic in Phillips' hand that provided the most convincing argument.

CHAPTER IV

PURSUIT

Ken's eyes riveted themselves on the gun in Phillips' hand. Sandy had seen it now too. Ken knew that from the redhead's quick intake of breath. And Ken was also aware of the fact that Sandy and himself, against the steep hillside, presented targets that could not possibly be missed.

Sandy turned to face down the slope, cautiously shifting his weight. Ken knew what was in his mind. The same idea had occurred to him. Their only chance against that gun was a sudden downward rush that-

Phillips was speaking again. "I want to talk to you," he was saying in his level voice. "But first look at this. Catch!"

Even as he said the word a small black rectangle came flying through the air. Instinctively Ken put up his hands and caught it. His fingers closed around smooth leather.

Dazedly his mind registered the fact that he held Phillips' wallet. And his eyes told him that Phillips was suddenly, inexplicably, grinning.

"Look at my credentials," Phillips said.

"We've seen them. We-"

"I don't mean my tourist visa and my school registration." The gun lifted slightly in a gesture that was both impatient and menacing. "Look in the back section."

The voice and the gun were both compelling. Slowly Ken opened the wallet.

Words leaped up at him from the official-looking identity card. Sandy saw them too, and repeated them in a voice that was loud with astonishment.

"Federal Bureau of Investigation!"

"You don't have to advertise it to the whole countryside." Phillips turned to the Mexican beside him. "Show them yours too, Ramon."

The Mexican shrugged. "If you wish it, Mort."

This time the wallet they opened was brown and battered, but the identity card in the back had the same official air. The printed words were in Spanish but their meaning was clear. Ramon Arturo Fernandez Gonzalez was a representative of the Mexican Federal Police.

Ken raised his arm to toss them back and then changed his mind and walked slowly forward, down the slope. Sandy moved along beside him. "All right," Ken said, knowing that the grin on his face must look a little foolish. "What did you want to talk about?"

Phillips was casually shoving the gun back into a shoulder holster concealed by his jacket. "Sorry about the melodramatics," he said, "but I couldn't have you go dashing off down the road carrying some pretty dangerous knowledge-and not knowing it."

The Mexican fired a rapid question at Phillips in Spanish.

Phillips grinned at him wryly. "How much do they know? Well, for one thing, they know you aren't dead -a fact our friends probably are not aware of yet. And I don't see any reason why those gentlemen should learn it. I also suspect," he added, "that neither of these boys believed my story of being a student at the National University." He eyed them questioningly.

"I was getting pretty suspicious of you," Ken admitted.

"But we didn't think you were-well, what you really are," Sandy added.

"You weren't supposed to," Phillips told him. "And I'm sorry you had to find out." He turned to Ramon. "Now that we've commandeered a car, let's use it. We can do the rest of our talking on the way."

"Good," the Mexican police officer agreed. "But first I will check the transmitter in my car. It is possible that it still operates."

Phillips looked at his watch. "How long ago did your 'accident' occur?"

The Mexican calculated swiftly. "Fifteen minutes ago, I would say."

"That would give them a chance to get beyond the next inspection station," Phillips muttered. "But maybe we can still catch them at Cienega de Flores. That's about eleven miles farther on, isn't it?"

The Mexican nodded. "It is worth the try." He had already squirmed up to the window of his car and now his head disappeared downward into the space in front of the dashboard.

After a few brief moments the loud-speaker in the car erupted into Spanish. The Mexican listened until the rapid speech came to an end, and then he answered it into his microphone. The boys could understand nothing of what he said except a scattering of si's and no's and the name Cienega de Flores. When the Mexican rejoined them on the ground again he was nodding with satisfaction.

"It is good," he told Phillips. "Both cars have passed the inspection post but neither has reached Cienega de Flores. Fortunately, there is an agricultural inspection station there-the guards search cars for any plants that may harbor the black fly." His white teeth flashed. "The two cars of our friends will receive a very thorough searching indeed. It may require half an hour or even more."

"Fine." Phillips grinned back at him. "And now let's get going."

Ken and Sandy glanced briefly at each other as they all started to climb back up the hill to the road. Sandy still looked slightly baffled at the sudden turn of events. Ken felt baffled too, but he also admitted to himself that he was extremely interested.

"Something tells me," he murmured quietly to Sandy, "that we are about to acquire the facts on a pretty lively story that will interest Global News."

At the top of the hill Phillips checked the road, to make sure that there were no other cars in sight before they all crossed the shoulder to the parked convertible.

"You get in the back, Ramon," Phillips said. "And keep down out of sight."

Ken slid behind the wheel and Sandy got in beside him. Phillips followed and shut the door. "O.K.," he said. "Let's go."

As Ken eased the car around the first sharp curve, Phillips leaned over the back of the seat to speak to his confederate. "My opinion is that you ought to leave us at the customs inspection post," he said. "You can pick up another car there and follow as soon as possible. And arrange for a crew to get your own car back up on the road, of course."

"Si." The Mexican's voice was slightly muffled but cheerful. "I agree. And you?"

Ken sensed that Phillips was looking directly at him as the man answered, "You'd better arrange for a car for me too, to be picked up at the earliest possible post."

Ken's news sense, already aroused, prompted his words. "A minute ago you were demanding our car at the point of a gun," he said. "And now that you've got us interested in whatever it is you're on the trail of, you're apparently going to shove us out of the picture."

"No, es posible-" The spurt of Spanish from the back seat broke off and began again in English. "It is not possible to report anything of this case to the newspapers."

"We wouldn't use anything that hadn't been checked with you first," Ken began stiffly. "We-" He stopped suddenly. "How did you know we had any connection with a newspaper?"

Phillips answered him. "We know everything about you," he said. "We know about all the scrapes you've been in in the past. We know when you left Brentwood -why you were held up two days in Texas."

The car lurched slightly as Ken twisted sideways to stare at Phillips. Sandy was staring at him too, his eyes wide with amazement.

Ken recovered his voice. "How?" he demanded.

Phillips grinned faintly. "It's a long story, and there's no point in going into it now. The next important item on the agenda is for us to get rid of Ramon, here, and then for you to get rid of me as fast as possible. I wouldn't have asked a ride from you in the first place, if I hadn't been in a spot. And the same is true of using your car right now, in this further emergency."

"But-"

Phillips interrupted almost before Ken had begun to speak. "There are no buts in this case. Anyway, isn't that what you wanted? 'A minute ago,' to use your own phrase, you wanted to drop us both-to leave us back there on the mountainside."

"Ken didn't want to," Sandy told him. "He wanted to find out what was going on. I was the one who said we shouldn't get mixed up in whatever it was."

"And you were right," Phillips assured him.

"But I've changed my mind," Sandy said. "If you know so much about us, you must know that-well, it sounds like bragging-but we have worked with the police a couple of times before."

"I know that. That's why I ran the risk of asking you for a ride. But at the time I didn't expect to run into any action quite so soon. I didn't think I'd be exposing you to real danger." Phillips shook his head. "And these boys play rough."

"But you're not one of them," Sandy said insistently.

"Right again," Phillips agreed. "But Ramon and I get paid to risk our necks, and-"

Ken interrupted him. "You get paid to keep law and order. And I distinctly remember that my civics teacher taught us that law and order are the business of every citizen-not just of the police."

There was soft laughter from the rear seat. "Mort, I think these boys would make good lawyers, no?"

"For a corpse," Phillips told him, "you make too much noise." He twisted around in the seat briefly. "You agree with me, don't you, Ramon? These boys have got to step out of the picture fast?"

"Absolutamente. Which means," the Mexican translated helpfully, "absolutely."

"But why?" Ken demanded. "We know you're interested in that other red convertible, and the man who has the lighter that lights with a green flame. We know you're interested in the gray coupe that was following Senor Gonzalez' sedan. I suppose that was the car that pushed him off the road, wasn't it?"

"Hmm." Phillips sounded thoughtful. "You figured all that out?"

Ken didn't answer. He pressed his advantage. "I suppose the reason you weren't able to warn Senor Gonzalez about the gray coupe, after you got its license when we stopped for a drink, was because you haven't had a chance to talk to him since you saw him outside the restaurant when we were having breakfast."

"You don't miss much, do you?" Phillips grunted.

Ken grinned. "We've been well trained. Sandy's father is a good newspaperman and so is mine. So, naturally, when we smell a story, we get curious. And we stay curious."

"Now look here," Phillips said, "I know we have no right to demand that you forget about what you've seen this morning, but-"

Sandy spoke in a musing voice, as if unaware that he was interrupting Phillips. "You know," he said, "if I were the men in the other red convertible, or the man in the gray coupe, and I saw you"-he looked at Phillips -"in this car, riding down the highway, I'd assume you were a hitchhiker, heading for Mexico City. But if later in the day I saw you in another car, heading down the same road, I'd wonder why you switched, especially if I noticed this red convertible still traveling along the same road."

"Sandy's right, you know, Mr. Phillips," Ken said quickly. "They've probably already seen you with us, when we stopped at that refreshment stand. Wouldn't you be less conspicuous if you stayed with us?"

"Police often commandeer cars," Sandy pointed out. "You don't even have to do that. We're volunteering ours."

Phillips groaned. "Don't call me 'Mr. Phillips.' My name is Mort. And his is Ramon."

Ken grinned. He knew Mort Phillips had been won over, even before he heard the detective's next words.

"All right," Phillips said. "I'll admit it's a temptation to stick with you for a while, for the very reason you just suggested. And I do know you're a little more experienced than most boys of your age-to put it mildly. What's more important, I know you're trustworthy. I know you won't make copy out of this situation until you've got a go-ahead signal from us. So I'm going to tell you what this is all about. And then, if you still want to let me ride along in your car for a while . . ." He sighed.

"May I suggest," Ramon said from the back seat, "that you make the story as brief as possible. We will be at the second customs post in a few minutes."

Phillips took a deep breath and began to speak in quick, concise sentences. "We believe-both the Mexican and the United States police, that is-that someone has established a criminal hide-out down here. We believe the culprit to be a United States citizen. We suspect this hide-out to be the center of a lucrative and efficient business. But we have no idea where it is. Our reason for believing it to be south of the border is this: the trail of two wanted United States criminals has been picked up down in South America, and it's pretty clear they went through Mexico. Furthermore, by the time we caught up with them, they had new faces, new names, and faked passports. That's why we think the hide-out is more than a convenient stopover point. Presumably it is run by an organization that can also supply plastic surgery and passport forgery."

"Fortunately," Ramon cut in, "to change a man's fingerprints is even more difficult than to change his face. It is, in fact, impossible. That is how the two men in South America were finally located. If they would talk, of course-" His pause was as eloquent as a shrug. "But they obviously are more afraid of somebody else than of the police."

"What I've told you so far is just background," Phillips went on. "But right now we have our first concrete lead for locating this hide-out. This is the lead that Ramon and I-and a dozen other secret service men on both sides of the border-are working on. The history of it began in Miami, Florida, about six months ago, when a certain bank teller came to the attention of the bonding company that bonds that bank's employees. The teller was known to be frequenting the race tracks, gambling heavily, and associating with notoriously shady characters. He had signed IO U's that he couldn't possibly pay out of his teller's salary."

When he stopped for breath, Sandy said, "But the man hadn't done anything illegal, had he?"

"No," Phillips agreed. "But a teller who is deeply in debt can spell trouble for a bank. He may easily reach a point where the thousands of dollars that go through his hands become a temptation he can't resist. Normally the bonding company-who would have to make good in the case of theft by a bank employee-would suggest that a teller with a background like that be fired. But this particular bonding company had already paid two big claims because of absconding bank clerks who had successfully disappeared. And through contacts with every police agency in the country, the company knew about the suspected hide-out down here in Mexico. So a plan was worked out. The police kept an eye on the teller, but the bank itself gave him no reason to think he was being watched."

"The customs post is just ahead," Ramon said quietly.

They could all see it-a small white building suddenly visible far below, at the foot of the mountain they were descending.

"O.K. I'm nearly finished," Phillips said quickly. "The hope was, of course, that if the teller did steal money, and attempt a getaway, he might possibly lead the police to the place we've all been looking for. My own agency was alerted, and so was the Mexican Federal Police. And last week things began to happen. The bank teller-his name is Frank Baron-bought a new car, under an assumed name, at a town fifty miles north of Miami. The car was a red convertible."

"Oh!" Sandy said. "I get it. That's why you knew so much about us."

Phillips nodded. "Any red convertible heading toward the Mexican border was under suspicion until cleared. Then, last Friday, when Baron's bank closed for the week end, he walked out with eighty thousand dollars of the bank's money. Ordinarily a theft at that hour of the day might not be discovered until Monday morning, but in this case, of course, it was discovered immediately. An hour later we knew Baron was heading toward Mexico in a red convertible.

"I was waiting for him at the border," Phillips hurried on, "on the Mexican side. Another member of my agency was in Laredo, ready to pick me up this morning. And that's when something went wrong. My confederate was at the United States customs station when Baron went through-both of them, of course, looking like innocent tourists. But by a fantastic stroke of bad luck, one of the customs officials knew my confederate and spoke to him by name. Worse than that, he said something like, 'I hear you're with Federal Intelligence now.' It's possible that Baron didn't overhear the remark, of course, but we couldn't take a chance. My confederate got word to me that he was stepping out of the case. And I got that word just about two minutes before I asked you for a ride. I hated to do it, but there wasn't time to make other plans right away. Ramon saw to it that Baron was held up at the Mexican customs until we were safely on the road, ahead of them. Ramon's part in the scheme was to follow along after me. And that's the story-so far."

Ken and Sandy were both silent for a moment. Ken spoke first.

"Have you any reason to believe that he really did make arrangements with the hide-out organization?"

"Our chief hope along those lines is what you told me over breakfast," Phillips admitted. "We'd suspected he had, because he seemed so confident. But your story of the lighter with the green flame, which was obviously a recognition signal, seems almost conclusive. I'd missed that, because I couldn't risk getting close to Baron there."

"So you sent back word about it at the first customs inspection post along the road-when you passed that sheet of paper from your notebook to the man leaning against the wall," Ken said.

Phillips nodded. "I said you didn't miss much, and I guess I was right. Anyway, that green-flame scheme seems to be one of the careful details this organization apparently worked out. The gray coupe, following along to check up, is another detail-one we missed until I saw the car on Ramon's tail, back there at that refreshment stand, and caught its license number. But by then it was too late to get through to Ramon about it."

"You have traced Baron to the border," Ramon said, "and that is the first important step. Now we here must do our part. Our plan is good, I think. But of course no plan is good unless it works. Even with our check points established at approximately every twenty-five miles, so that we will certainly know the general area where they leave the highway, they may still slip through our fingers."

Sandy, who had spent much of the previous day studying maps of Mexico, said diffidently, "But there aren't many side roads leading off this highway that they could take, are there?"

"Not many main roads," Ramon agreed. "But there are countless small lanes that are passable in dry weather-and this is still the dry season. It is helpful to know that there are two cars to look for," he added more cheerfully. "If we pinpoint the general area, and send up our scouting planes, two cars should be easier to see than one."

"Then you're not going to arrest the driver of the gray coupe for having forced you off the road?" Sandy asked. "Isn't there a chance he'd talk?"

"Too risky," Mort said decisively. "If he's picked up now, they're likely to suspect we're on their trail. Surprise is our best weapon. If Ramon is the only police officer they've spotted so far, they may think they're in the clear now-and this may inspire just the degree of overconfidence that leads to carelessness."

A moment later Ken was pulling to a halt before the customs-house inspection post.

Ramon got out of the car and identified himself. The inspector saluted smartly, listened to Ramon's rapid instructions in Spanish, and then disappeared inside the customs house.

"You are free to proceed without the formality of an inspection," Ramon said dryly. "The car I use will have a radio," he went on, "and any of our highway posts can flash a message to me. I will maintain a position a few miles to the rear of you-far enough behind to spot any attempts they may make to conceal themselves temporarily and then double back on their tracks."

"Right." Mort nodded. "We ought to reach the agricultural inspection post at Cienega de Flores in about fifteen minutes. So you might telephone ahead there and tell them to release the two cars a quarter of an hour from now. Then we'll be right behind them."

"I will do that." Ramon shook hands briefly with all three of them, in the traditional Mexican gesture of farewell. "Good luck, amigos. I will expect to pick you up, Mort, at the station nearest the point where the cars leave the highway. At that point we dismiss our young friends with gratitude-no?" Once more his white teeth flashed.

But his final words were sober. "Be careful. They have much at stake, these bandidos."

CHAPTER V

DELAYING TACTIC

The distance from the customs inspection post to Cienega de Floras was seventeen miles. Phillips had told Ramon Gonzalez that they would reach the agricultural station in fifteen minutes. Ken concentrated on his driving.

Once he had to brake to a sudden halt to avoid running over a burro that unexpectedly trotted to the middle of the road. And once, near a narrow bridge, he had to wait while a whole family loaded themselves and half a dozen wicker baskets aboard an already crowded bus. But most of the time he kept the speedometer needle hovering over the seventy mark.

Exactly fifteen minutes after they left Ramon, Phillips pointed far ahead to a small white structure at the side of the road. There appeared to be a car drawn up in front of it, but the distance was too great to identify its shape or color.

"The binoculars are in the glove compartment," Ken reminded Sandy.

Sandy had them out in an instant.

"Thanks." Phillips grinned briefly as he accepted them. "If you're trying to convince me I made a wise decision in coming along with you, you're doing a good job." For a moment he peered intently through the glasses. "That's the gray coupe, all right. And it's just pulling out."

Ken had reduced his speed while Phillips explored the situation ahead. Now, at a gesture from Mort, he stepped down on the accelerator for the last few hundred yards that brought them up to the inspection post.

A uniformed inspector stepped forward immediately, looked at the convertible's license plate, checked it with the number written on a slip of paper in his hand, and then saluted.

"They have just left," he reported. "The red car is two minutes ahead of the gray." His handsome young face lighted briefly with a smile. "I believe I am to be reported to my superiors for delaying them unnecessarily. I explained that because insects are quite small it is necessary to search for them with great care, but they found this thoroughness most irritating."

"I'll report your thoroughness myself," Phillips told him, "with gratitude."

"Gracias, sefior. In the red car," the inspector added, "one of the men carried a brief case which he assured me contained nothing but papers. In accordance with my instructions, I did not insist upon examining that particular piece of luggage."

"Excellent," Phillips said. "And now if you'll send a message back to Gonzalez, we'll be on our way. Tell him we reached here in good time, and are right behind them."

"Si, sefior. Immediately."

"Gracias."

The inspector saluted once more as the car moved off.

Sandy unfolded a map of Mexico so that the area around Monterrey was visible.

"Twenty-three miles to Monterrey," he muttered, and glanced at the speedometer. "That's about twenty-five minutes, at this rate." He sighed. "Don't you suppose there's a chance your friends might stop there for lunch, Mort? I'm getting hungry."

"I suppose there's a chance," Phillips said. "If they haven't turned off the road by then-which," he added, "we don't really expect them to do. The country beyond Monterrey is much hillier than this, and we assume the hide-out is somewhere in the hills. It stands to reason they'd choose a spot in country that is little traveled and little known. Anything on the plains around here could be too easily spotted."

He, too, studied the map for a moment. "This highway goes straight through Monterrey, of course. But three other good roads leave the city. So our checkup in Monterrey must be very careful."

Ten minutes had gone by and as many miles. Already there were signs of the approaching city. Roadside billboards advertised hotels and restaurants, tires and beverages. People on bicycles and others on foot had joined the thickening traffic stream.

"Close up a bit," Mort said, "if you can."

Ken struck an open stretch and picked up even more speed. But in another few miles he was forced to drop down below fifty.

"I never saw so many buses in my life," he muttered, swinging around one only to find himself behind another.

"Easy!" Sandy cautioned suddenly. "I think I caught a glimpse of the gray coupe.”

Ken ducked ahead of a big truck loaded with cattle and stuck his head briefly out of the window. "Right," he reported. "He's about five cars ahead, pocketed behind a tank truck."

At the end of another five miles they were forced to slow down to thirty. They had reached the outskirts of the city proper. Dairies, factories, and housing developments edged the highway now, and buses stopped at brief intervals to pick up or discharge passengers. Cross streets became more numerous.

And then suddenly they were in the heart of bustling, highly industrialized Monterrey. Ken found himself crawling forward between one of the inevitable buses and a gleaming new limousine.

"Haven't spotted the gray coupe lately," he reported. "He may even have turned off when I was held up at that last traffic light."

"We'll soon know," Phillips told him. "There's a police booth up ahead just a few blocks."

Five minutes later he stopped beside a traffic officer who checked their license number and then queried, "Senor Phillips?"

Mort nodded.

"Both cars have passed this point," the officer said in heavily accented but intelligible English. "The red passed five minutes ago. The gray two minutes ago. I think they proceed on into the city."

“Gracias.”

"Momentito, senor." The officer held them with an upraised hand as Ken started to release the brake. "Capitan Gonzalez also wishes that you have this message. He follows you now in a black sedan. License number X-258-0. Also, senor, I have notified all check points in Monterrey that the two cars have passed this station." He stepped back and saluted.

"Bueno. Mil gracias." Mort nodded his satisfaction. "Please tell Gonzalez that we are still following."

When Ken had joined the slow lane of traffic once more, Mort said, "Watch the side streets. Mexicans sometimes seem to believe that a full-stop sign is a challenge that should be met with a burst of speed."

The boys were not surprised to discover that the center of Monterrey, like the center of most Mexican towns, was a green path-marked square. As Ken drove along one side of it, Sandy said wistfully, "There's a restaurant. I don't suppose-"

He broke off suddenly and his next words were spoken in a different tone of voice. "There's the other red convertible-parked right in front of that big hotel!"

Ken and Phillips both looked where Sandy was pointing. The hotel stood on a street running off at a right angle and bounding another side of the square. The convertible was standing almost directly in front of the main entrance.

An instant later Ken spotted the gray coupe, parked on the same street but on the opposite side. Both cars were empty.

"What do we do now?" Ken asked Phillips. "They're probably all having lunch in the hotel restaurant."

"That's what we'll do too," Phillips decided. "It's a popular tourist stop, and you two are a pair of ordinary tourists."

Ken swung the car around the corner and a moment later found a parking place less than fifty feet from the gray coupe.

As he maneuvered into position he said, "The gentleman with the lighter is likely to speak to us, if he sees us. Do you want us to remember him?"

"Of course," Phillips said. "It would look odd if you didn't. And you can refer casually to having offered me a ride. I hope he does speak to you, in fact. I'd like to get a look at him at close quarters."

"I will give a magnificent performance of a tourist who has nothing on his mind but food," Sandy assured him.

Ken laughed. "And it won't even be acting, so far as the food is concerned."

Before Ken had his door opened, a small boy with tousled black hair, bright black eyes, and a very clean white shirt above a shabby pair of blue jeans appeared beside the car.

"Watch the car, meester?" he suggested.

Ken looked over his shoulder at Mort. "Should we have the car watched?"

"Sure," Mort told him. "It's standard practice here." He had stepped out of the car and now came to stand beside the boy. "Bueno, chico," he told the youngster. "But watch it well."

"Si." The boy grinned happily. "I watch well, meester."

Phillips ruffled the black hair before he turned and walked toward the hotel with the boys.

They walked through the cool, tile-floored lobby to reach the restaurant beyond it. Several tourists and traveling businessmen sat around the lobby, but Ken saw no sign of a lean, tanned face.

The dining room, large and L-shaped, held fifty or more tables, each covered with a snowy white cloth and set with sparkling silver. At first glance almost all of them seemed occupied.

But a headwaiter appeared in an instant, his welcoming smile assuring them that they would not be turned away.

"Buenos dias, senores," he said. Then he shifted to English. "A table for three?"

"Please," Mort told him.

"This way, please." He moved off between the tables, toward the angle of the L, leaving them to follow.

As they rounded the corner and continued on their way to the distant table the headwaiter was indicating, Ken saw the face he had been looking for. He turned his own head quickly in the other direction.

"Here you are, gentlemen." The headwaiter stood aside while they sat down, then stepped forward to present them with large menus that brought an instinctive smile to Sandy's face. "I will send a waiter to you in a moment." With a final smile the man left them.

Ken opened his menu and leaned forward slightly so that he could speak in a low voice.

"Mr. Green Flame is at a table against the wall, near the corner to my left," he said quietly. "I suppose the man with him is Baron?"

Neither Sandy nor Phillips looked immediately in that direction. Both studied their menus for a moment. Then Sandy leaned back and tilted his head casually, as if considering the relative merits of the various dishes.

"Yes," he said a moment later, "that's Green Flame all right."

Phillips had been glancing around the room with the open curiosity normal to tourists and students alike. "That's right," he murmured. "Baron it is. And looking a trifle nervous, I'd say."

A moment later, as he appeared to be studying the gay murals decorating the walls, he added, "See any sign of the man driving the gray coupe? Or don't you know what he looks like?"

Ken shook his head. "No, I didn't see him as we came in, and I don't now. I think I'd remember him, all right. Very dark hair, swarthy skin, and a noticeably low forehead."

"They're probably being careful not to be seen together," Phillips said.

Just then, Ken, seated in a direct line with Baron's associate, lifted his arm in a wave of greeting. As he smiled across the room he said openly, "Sandy, there's the man we saw at the customs station this morning. He's saying hello."

Sandy looked openly at the opposite table and he too smiled and raised his hand in a casual wave.

Then, careful to show no reaction to Phillips' cautious wink, they both studied their menus again.

"I could eat everything on the list," Sandy said, "but I'm going to play this smart. I'm going to order sandwiches. Then if, for any reason, we-" he lowered his voice-"we have to leave here suddenly, I can pick up my meal and walk."

Phillips grinned. "You're sure this decision isn't based on the fact that sandwiches are not likely to be served with hot sauce?"

"It is not," Sandy said indignantly.

"I know." Phillips put his own menu down. "As a matter of fact, it's a smart idea. Though we'll let them leave first, and we'll wait here until we get word as to which road they take out of town."

Ken spoke without moving his lips. "Here he comes."

The expression on Phillips' face didn't change. ". . . by all means Vera Cruz," he said, letting his voice raise slightly. "The beach there is wonderful. And if you like fishing you're-"

"Hello."

Phillips broke off as the word sounded close beside him, and he and the boys all looked up at the tall man standing near Ken's chair.

"Hello," Ken said, and Sandy's voice echoed the greeting.

"I see you got this far all right," the man said pleasantly. "It's a fine road, isn't it?"

"Swell," Ken agreed. "When you said you knew the road so well, I assumed you'd be way ahead of us by now. But it's easy to make time on this highway." He smiled. "Though mostly we weren't traveling quite so fast as you seemed to be when you passed us a while back where we'd stopped for a drink."

"I saw you too," the man said. "But those little stands out in the open don't appeal to me. I've been aiming for this nice cool restaurant for the past hundred miles." His smile died abruptly and his voice sharpened. "Thought for a while we never would get here. Some fool agricultural post back there a way held us up for nearly half an hour. The idea seemed to be that we might be secretly carrying a cargo of poisonous insects."

Sandy laughed. "We were stopped there too. Black fly, or something, I think they're checking on."

"I don't even know what it was," the tall man said. "But I had the distinct impression they were giving us a special third-degree inspection. Several other cars and trucks went through while we were still held up there."

"The ones that went through quickly were probably local vehicles," Mort said easily. "They wouldn't bother searching those so carefully. But out-of-state, out-of-country cars usually get a thorough going over."

The man shrugged, but his eyes were intent on Phillips. "I wouldn't know. Do you make this run often, to be so well informed?"

"I've made it several times," Mort said. "I'm a student at the National University, you see, and I have to return to the border every six months to renew my visa." He grinned at Ken and Sandy. "I was lucky this time. I've got a hitch all the way to Mexico City. Sometimes I find myself stuck in a car that's going only a few miles."

The man nodded, almost absent-mindedly, and then glanced back toward his own table. "Well," he said, "I just wanted to say hello. Have a good trip."

"Thanks," Sandy said.

"Yes, thanks," Ken added. "It's been fine so far."

When the man was seated once more opposite the plump figure of Baron, the bank teller, Sandy let out an explosive sigh.

"Whew!" he said. "The gentleman sounds a trifle suspicious."

Mort nodded slowly. "It's possible. Those questions about the agricultural inspection station-" He shook his head. "I don't like it. If he's suspicious already, he may possibly be tying you two in with this, and that's what I'd hoped to avoid. Now I wouldn't feel safe sending you on your way to Mexico City without an escort."

A waiter appeared beside them at that moment, and they all ordered sandwiches and coffee.

"As quickly as possible," Sandy added.

"Si, sefior." The waiter hurried off.

"You both did a good job, though," Phillips said. "Maybe I'm just imagining things-and you too, Sandy."

"Green Flame is leaving-alone," Ken said quietly.

The others couldn't see without turning around, and Ken reported that the tall man had disappeared in the direction of the lobby. Baron, left alone, sipped coffee and kept his eyes lowered to the table.

Phillips thought for a moment. "But he must be coming back. He wouldn't leave Baron here. There's no point in our dashing out after him."

Their waiter returned then with their food, and devoted himself for some minutes to pouring their coffee and making certain there was nothing else they needed at the moment.

Just as he left, Ken reported that the tall man had returned, said something to Baron, and then snapped his fingers for a waiter.

"Relax," Ken said. "He's ordering more coffee."

The boys and Phillips finished their own coffee and sandwiches, but Baron and his guide still lingered at their table.

"Dessert?" Sandy suggested hopefully.

Phillips nodded. "We might as well."

The waiter brought them a creamy custard in a caramel sauce, and more coffee. And just as it arrived the two men in the other corner stood up. Baron was clutching a brief case in his hand.

"Too bad." Sandy stared down at the dish in front of him. "Looks good, too."

"It is good," Phillips assured him. "Go ahead and eat it. I'll leave you in a minute and phone the police. There's no use our starting out until we know which road they're taking out of town."

When the two men had had time to get through the lobby, Phillips left the dining room to make his call. He was back in less than five minutes.

"They'll send word through to me here," he said. He ate his own dessert then, and impatiently ordered a third cup of coffee.

Ten long minutes crawled past, after the completion of his phone call, before a waiter approached.

"Senor Phillips?" When Mort got quickly to his feet, the man added, "Telefono, senor."

Ken paid the bill, then he and Sandy too went out to the lobby. Phillips was using the phone at the clerk's desk, speaking into it in a guarded voice.

"Bueno," he said finally. "Gracias." He set the phone back in its cradle, thanked the clerk, and turned to the boys. "Both cars are heading right on down the main highway toward Mexico City. They've already passed the check point at the city limits. Let's go."

"Maybe Green Flame wasn't suspicious of us after all," Sandy said as they headed swiftly for the door. "If he had been, he might have left the gray coupe behind to keep an eye on us."

"I hope you're right." But Phillips didn't look entirely convinced.

Ken was unlocking the convertible's door when he heard a sharp hiss directed at him from behind the next car. He turned curiously to see the young car watcher peering at him with bright eyes.

Phillips saw the boy, too, and fished in his pocket for a coin. "Here," he said, tossing it. "Thanks, chico."

The youngster caught the coin deftly and then sidled out of his place of concealment.

"Senor," he whispered cautiously, looking up at Phillips from beneath the mop of black hair.

"What's he scared of?" Sandy asked, grinning down at the boy.

"What's the matter, chico?" Phillips asked, and then repeated the question in Spanish.

"Man come," the boy said softly. "To steal cap."

Phillips bent down. "What cap, chico?" He listened closely to the soft torrent of Spanish that answered him, and then he looked up at Ken and Sandy. "He insists a man tried to steal the valve cap from your left rear tire. He told the man to go away and the man chased him. That's why he was hiding."

"But the cap is still there," Sandy pointed out.

"Let's take a look at it." Ken moved swiftly to the left rear tire and bent down. "It's loose," he said an instant later. He put his ear as close to the valve as he could. When he glanced up at Sandy and Phillips his face was grim. "Pretty cute," he said. "The tire is losing air. It would be flat in half an hour."

"So that was it!" Mort Phillips muttered. "A perfect way to delay us. Oh, no," he added softly, "they're not suspicious-not much!"

CHAPTER VI

INTO THE QUARRY

Sandy rummaged through the glove compartment for a valve wrench, tightened the leaking valve, tested, and then replaced the cap.

"O.K.," he said. "But we'd better have the tire pressure checked."

Phillips patted the youthful car watcher on the head and gave him a peso before he joined the boys in the car.

The youngster's eyes opened wide. "Muchas gracias, senor."

"Many thanks to you" Phillips replied.

At the first gas station they passed they had the tires checked and the gas tank filled, while Phillips eyed his watch impatiently. He was still tense when Ken started the car up again and they crossed the Santa Catarina River, leaving Monterrey behind.

Almost immediately they were climbing through steep-walled canyons, along a road that twisted and turned like a snake. Speed was impossible.

Phillips sighed and deliberately leaned back in the seat. "After all," he said, "they couldn't have been making good time here either." But he looked a little less grim when they finally emerged onto level ground again and Ken could push the car up to seventy.

It was two thirty when Phillips directed a halt in front of the police headquarters of the little village of El Cercado, about twenty-two miles south of Monterrey. The report awaiting them there was more or less what they expected. Baron's car, with the gray coupe some distance behind it, had already passed the junction of a road leading east through Montemorelos.

"That means they're more than thirty miles ahead of us," Phillips said, "and still on the main highway. Can you close up a little?"

"I can try." Ken bore down hard with his right foot almost before the car moved into high gear. "I wonder how far behind they think we are?" he added.

But at the Montemorelos junction they learned that the two cars were maintaining their lead-had even bettered it slightly. The police officer there, appearing suddenly out of what appeared to be a tiny grocery, reported that both cars had just passed through the town of Linares, thirty-three miles beyond.

Ken made Linares in twenty-five minutes, along a road often bordered by the orange groves Phillips had referred to that morning. A corpulent little man in a tight-fitting uniform, awaiting them at Linares, shrugged his shoulders when Phillips first questioned him. He had not yet been informed, he said, that the two cars had been sighted at the next check point in Villagran, thirty miles south. But the momentary excitement which this announcement aroused died down an instant later when the officer's radio crackled into action. The Villagran check point had just sighted the cars, still traveling south.

"On our way," Phillips muttered. He attempted a grin. "This highway goes the full distance to the Guatemala border. Maybe it would have been smarter just to take a plane down there and set up our check points in Guatemala,"

The news at the Villagran station was a repetition of the earlier bulletins. Eighteen miles beyond, at the town of Tomaseno, set in the midst of cornfields and fields of towering sugar cane, the news was the same. Twenty-four miles still farther, at the junction of a road leading off to the little village of Santa Engracia, there was again little change. Ken had lessened slightly the distance between himself and the two cars ahead, but Baron's car and the gray coupe were still nearly twenty-five miles in the lead.

"They've just passed the check point at the northern boundary of Ciudad Victoria," Phillips said, as Ken got the convertible underway again. "Victoria is a sizable city, and there are two roads leading out of it, besides the highway. So we may hear something interesting there. I'm getting a little tired of this monotonous 'Still on the highway heading south, senor.'"

"You don't think the hide-out may be in some large town?" Sandy asked, as the smooth road slid away beneath them. It was nearly five o'clock now, and the shadows were lengthening. They were beginning to see farmers plodding homeward after a long day in the fields, their tools slung over their shoulders and their burros ambling at their heels.

"We don't think so," Phillips agreed, "because the Mexican police have already pretty well explored that possibility. Any foreign establishment is easy to spot in a Mexican town. No, we assume it must be in the country somewhere." He stretched cramped muscles restlessly. "And I wish we could get a lead on it while it's still light. Prowling around some of these rugged hills in the dark is not my idea of fun."

"But if Victoria is a big city, they might be stopping there overnight, if they've still got a long way to go," Sandy pointed out.

Phillips shrugged. "That's possible, I suppose. But I should think they'd be eager to get Baron to the hideout as soon as possible."

Traffic thickened for the last few miles before they reached Victoria, and Ken's time for the twenty-four miles from the Santa Engracia junction was close to half an hour. All three of them felt a sense of letdown when the report given to them at the northern boundary of the city was a replica of everything they had heard before. The cars had left Victoria by the main highway, still bound steadily south. The only different note lay in the speed of the cars ahead. They were now only a little more than fifteen miles in front.

"Loafing around waiting for dark?" Phillips speculated, as they got underway once more.

"Or maybe just held up by this city traffic," Ken pointed out, stopping for a red light at a busy intersection.

Phillips agreed. "Sorry you're rushing right through this place," he added, with an attempt to revive his guidebook manner of the early-morning hours, which now seemed so long ago. "It's not much to look at if you're in a hurry, but there are some pretty spots around here, and that river we crossed just before we entered the town has some wonderful fishing." They were just topping a hill that rose steeply at the southern edge of the city and Phillips told the boys to look back at the town nestled in the shadows.

"Don't worry," Ken assured him, after a quick glance backward. "We enjoy sightseeing, but we can do ours later."

"There's just one sight I want to see right now," Sandy said, "and that's the place Mr. Baron is heading for."

The road dropped from the hilltop down into another plain, and ran almost level for about twenty-five miles. Then it mounted steeply into the short range of hills called Le Mesa de Llera. At the check station just before they started up the first sharp rise, Phillips made no effort to conceal his disappointment when the same repetitious report was presented to them again. The two cars ahead were already through the mesa hills and had just passed the small town of Llera at the foot of the southern slopes.

"These hills are pretty deserted country," he muttered. "I really thought maybe this was it. All right, let's go."

It was six fifteen and the hills ahead looked gray and forbidding. Ken switched his lights on, their beams up, so that he could keep a sharp lookout for the burros and cattle that roamed around even on these sparsely vegetated slopes. But the sharp turns and the dusky half-light held his speed down. He heaved a sigh of relief when the headlights finally slanted downward for the last time, and the car descended the final hill to the plain below.

"That gas station up ahead is our check point," Phillips said wearily.

There was still a touch of pink light high in the western sky, and the level ground still held much of the sun's warmth. But dark was almost on them now, and the air had a promise of the night's chill.

"Want me to drive?" Sandy asked. "You've had a long day."

"It's all yours," Ken told him.

Phillips leaped out the moment they reached the gas station and the boys shifted places. Ken was still wriggling his shoulders, to ease the cramped back muscles, when Phillips returned.

"They've already passed through Santa Ines, twenty miles on," Phillips said. "The road's not so winding from here on, so we ought to be able to get closer to them again." He noticed the shift and added, "I can drive too, you know. Any time you want me to take over, just say so."

Ken managed a grin. "Your turn can start at the Guatemala border."

The run to Santa Ines was swift, and the word there was that the cars ahead had already passed the check point in the sizable city of El Mante, twenty-five miles beyond. Sandy made good time on that stretch too, but even so it was seven forty-five and completely dark when the car drew up at the tourist information booth where the El Mante post was located.

All three left the car there and entered the cheerful well-lighted building whose walls were decorated with striking posters. Phillips held out his credentials and they were immediately shown into an office behind the main room, where a uniformed highway patrolman sat before radio equipment. The man began to speak quickly, in Spanish, without any of the customary formalities of a Mexican greeting.

Ken and Sandy, still blinking in the bright light, and numb with weariness, stiffened into interest when the muscles of Phillips' face grew suddenly taut.

"They reached here at seven," he translated for them, "and passed the post at the southern edge of Mante at seven nine. They did not turn off on the road heading east to Tampico-the junction's just south of here. But they haven't yet reached Antiguo Morelos, which is only seventeen miles beyond."

Ken calculated swiftly. "About thirty-five minutes for seventeen miles, and they haven't covered it yet." Mounting excitement dispelled his weariness like magic, but he said, "Could they have stopped somewhere for dinner?"

"We'd have had a report if men traveling in a red convertible stopped at any restaurant on the route," Phillips said.

"Flat tire?" Sandy suggested.

"Possible, of course," Phillips agreed. "But I think-" He turned back to the officer and made a request in Spanish.

"Si," the officer replied, "immediatamente." He snapped switches and turned dials, barked into the microphone, and waited. The voice that answered him through the loud-speaker a moment later was distorted but recognizable as Ramon's.

Phillips took the microphone and reported the news. "So this might be it," he concluded.

"Bueno," Ramon said tersely. "I am only a few miles from El Mante now and will be with you in a few minutes. You might check with Antiguo Morelos again in the meantime. Hasta luego."

Once more, competently, the officer manipulated his controls until he was in touch with the next check point. The cars had still not appeared there.

Phillips rammed clenched fists into his pocket. "No use sending up scouting planes at night," he muttered. "That will have to wait for daylight."

Gonzalez arrived two minutes later. For an instant the boys didn't recognize him. He no longer wore the clothes that had been torn at the time of his accident. Instead he was in a wrinkled pair of khaki trousers and a battered leather windbreaker. But the briskness of his manner contradicted the casualness of his clothes. And his first words showed that he had been busy at his microphone while he covered the past few miles.

"Another car is already posted at Antiguo Morelos," he said. "If they do go past that point, the car will follow." He spoke directly to his fellow officer. "And you will please maintain the watch here, to make sure the cars do not double back on their tracks and head north again." The officer saluted and disappeared to alert his associates.

"Are we going on?" Phillips asked.

Gonzalez nodded. "But at a careful pace, keeping watch for any signs of a car having left the road-not," he added with a brief smile, "that I think we will see much in the dark. At Antiguo Morelos a hunting guide of the region will be waiting for us. If we have no further news by the time we reach there, so that we must assume the two cars have left the highway between this point and that, we will make a careful study of a map of the region with the assistance of the guide." He shrugged. "We know there are no paved roads leaving the highway between the two points, but the guide may know of trails that do not show on the map. We are ready?"

He flashed a brief grin at the boys before anyone had a chance to answer him. "Our official dossier on Sandy Allen included a reference to his fondness for food. Sandwiches will also be awaiting us at Antiguo Morelos."

The black sedan Gonzalez was driving led the way this time. His winking taillights just ahead, and the knowledge that the chase was finally closing in, gave new spirit to the three in the convertible.

Phillips grinned into the darkness. "I was feeling tired ten minutes ago. Now I could go on all night."

"Me too," Sandy said. "Though I admit I'll feel even better after we get those sandwiches."

There was little traffic on the road now, and for some miles the land was fairly flat. Ken, leaning forward to study every foot of the shoulder visible in their headlights, said, "This doesn't look much like the kind of country you expected to find the hide-out in."

"There are some hills fairly soon," Phillips said.

The road began to rise a few minutes after he spoke, and soon it was twisting and turning, climbing and dipping, in the manner they had already encountered several times earlier that day.

Their watchfulness was futile. One by one the tortuous miles slid away under their wheels without yielding any helpful sign. And then suddenly they were pulling up behind the black sedan in front of a whitewashed building in Antiguo Morelos. It was a little past eight thirty. Gonzalez, they knew, had received no further information over his car radio, or he would have stopped to let them know about it. They were at his heels as he trotted into the bare plain office, after a brief word with the officer outside.

Three men awaited them. The squat, swarthy figure was obviously the chief of the local police, and the second younger man was a police officer too. But the third man wore denim jeans and a dark shirt, and his slight figure seemed almost lost inside the folds of a serape, the poncholike woolen garment which serves as the Mexican's protection against cold and rain. This particular serape had once been black with a white border, but the colors had blurred to two soft shades of gray, one darker than the other. The man's small head, covered with a thatch of thick black hair, emerged through a hole in the center, and the hat he held in his gnarled brown hands was a broad-brimmed straw sombrero. Ken realized that this was the guide Ramon had requested.

Gonzalez conferred briefly in Spanish with the police chief and then took the map the officer handed him. Unfolding it to its full size, he spread it out on a desk and then beckoned the guide to join him. The man obeyed silently, and Ramon slowed his own normally rapid speech to explain fully what he wanted.

The man nodded his comprehension, still without speaking, and then bent over the map.

Ken tried to curb his impatience by studying the heavy sandals the man wore. The soles, he noticed with surprise, were not leather, as he had assumed. They had been cut from a thick rubber tire and fitted with thongs that held them in place.

"Hay dos" the man said quietly.

" 'There are two,' " Phillips translated quickly. "Two roads, Ramon, going off the highway between here and El Mante?"

Ramon nodded. He questioned the guide sharply, and followed the brown finger as it traced lines on the map.

Phillips murmured a running translation of the information that Ramon was eliciting. "They're both just small trails, going back into the hills for a few miles each. One ends at a mountain lake that sports fishermen sometimes use. The other ends at a deserted quarry. No houses along either of them."

Phillips' voice trailed off on the last words and his brow furrowed with a frown. "He's sure?" At Ramon's nod he added, "Then maybe our friends just ducked into one of them temporarily, to cover their tracks, and will be coming out again soon."

Ken felt the letdown too. "If that's-" But he broke off because Ramon was speaking again.

"We will have to check the trails, nevertheless. This man knows his business"-he patted the shoulder beneath the faded serape-"but after all we are presumably dealing with very clever criminals. They may have a way of continuing on from the end of one or the other of these little roads."

Once more he rapped out commands in Spanish, with a final word to the guide. The man nodded quietly. "He will go with two police officers in a jeep, to lead the way," Ramon said. "We will follow in my car."

Sandy opened his mouth to mention the promised sandwiches, but closed it without speaking. It occurred to him that this was a point at which Gonzalez might decide to leave Ken and himself behind. It was even better to go hungry, he decided, than to call attention to themselves in any way. He and Ken moved unobtrusively toward the door with the others. Sandy was the last one through. Just as he crossed the threshold, the police chief dashed after him to thrust a newspaper-wrapped package into his hand. Sandy grinned. It was unnecessary to understand the exact words of the swift apologetic explanation.

"Gracias," he murmured, hoping that he was correctly remembering the Spanish for "Thank you."

Neither Phillips nor Ramon made any objection when the boys slipped into the back seat of the black sedan. Gonzalez got behind the wheel and Phillips sat beside him. In an instant they were zooming along the highway once more, back toward El Mante. Ahead of them roared the jeep.

Sandy unwrapped the newspaper, and the white napkin inside it, and revealed a sizable stack of sandwiches made with thick slices of crusty bread. Silently he thrust two over the back of the front seat.

"Thanks. Where'd these come from?" Phillips took them gratefully. Then he swung around. "I'd planned to make you two stay back there! But in all the rush-"

"Where the food goes, there go I," Sandy said, around a mouthful.

Phillips glared. "It's too late to send you back now. But-"

The jeep ahead of them slowed down halfway around a curve and braked to a stop along the right shoulder. Gonzalez pulled on his own brakes.

Phillips, abandoning his argument with the boys, jumped out of the car with the rest to stand bending over the figure of the guide, squatting on the ground in the glare of the jeep's headlights. Past the guide's feet several sets of tire tracks crossed the shoulder and seemed to vanish in the darkness.

"But there's no road here," Ken protested.

Gonzalez had turned a flash on. "Not what you call a road, maybe, but look."

The ground fell away sharply below the shoulder, but the flashlight showed the tire tracks continuing down the steep slope that plunged toward the bottom of a ravine. And when Gonzalez lifted the flash, and directed it at the opposite bank of the ravine, they could all see that the tracks appeared there too.

"This is the quarry road," Gonzalez said. "Come on." He gestured to the jeep driver and the man got back into his sturdy little car, with the guide and the second policeman beside him. Gonzalez returned to the sedan.

The others followed.

"Will your car make it?" Phillips asked.

"Certain cars have already made it," Gonzalez pointed out dryly. "We will at least make the attempt."

They watched the jeep's nose point downward into the abyss. For a moment it seemed to hesitate, and then it dropped slowly out of sight. Gonzalez followed. The big car went over the edge with a sickening lurch. There was a swift skidding drop, as if it were out of control, and then the brakes took hold and the boys could feel and hear the wheels digging into the loose dirt and gravel. They braced themselves by clinging tightly to the back of the front seat.

Then, suddenly, for a few brief yards, the car was jolting across a comparatively level dry stream bed. Up ahead the jeep was already beginning to climb the opposite bank of the ravine. When the front wheels of the sedan tilted the big car upward too, Ramon fed gas to his engine and it growled in response. But slowly the car inched upward, its weight and the extra size of its tires supplying enough traction to overcome the grade. The car finally topped the rise, and its springs seemed to echo the relieved sigh that went up from the four occupants.

But the jeep was now descending another, shallower ravine and the big car turned its nose down again. The ascent on the opposite side, however, was so steep that some crude road making had been done to render it passable. The last several yards below the top were gouged out of the crest, so that the tracks rose at a more gradual angle than the bank itself.

When the sedan finally eased itself over the crest, between two miniature cliffs of stone, it came to an abrupt stop. The jeep had already halted, immediately ahead.

Ramon cut his lights and the jeep's lights went off too. A moment later the occupants of both cars were gathered in a close huddle. Gonzalez spoke a word of command and the guide disappeared into the night.

"This is the old stone-loading area," Gonzalez told Phillips and the boys. "The trail runs on across it for about two hundred feet to the brink of the quarry. The quarry is not in use now, and is full of water."

"No trail goes on around it?" Phillips asked.

"The quarry backs up against a steep cliff," Gonzalez explained. "There is no way to drive around it. So this is probably a wild-duck chase, but-"

"Goose," Sandy corrected involuntarily.

"Eh?"

Just then a low-voiced call reached them and a flashlight winked from across the clearing. The guide's beam glinted briefly on something bright-the chrome trim of a car.

They all started toward the light instantly, their flying feet raising little clouds of thick dust. And then they were standing in a silent group around the gray coupe. It was empty.

Four more flashlights winked on, in the hands of Phillips, Gonzalez, and the police officers, and swept in wide circles. But of Baron's red convertible there was no sign.

CHAPTER VII

CONTACT BROKEN

For a moment they all stared blankly at the gray coupe, as if expecting it to explain its presence. There was something confusing in seeing this one car alone, when they had been following the two partnered cars for so many miles.

Nobody spoke, and only the guide moved. He was still diligently covering the surrounding ground with the light of his small flash. Suddenly the beam's gyrations ceased, and the small, silent man spoke a single word in Spanish.

Gonzalez spun around.

They all followed the direction of his glance and saw what the flashlight illuminated-a set of tire tracks moving toward the edge of the quarry, somewhere ahead in the darkness.

Gonzalez spoke a command, but the guide had not awaited it. He was moving slowly along the tracks, following the marks in the heavy dust with the glow of his light.

His dark hand, thrust sideways from beneath his scrape, brought them all to a halt. The tire tracks ended abruptly at the rocky rim of the quarry pit.

The flashlight beam plunged over the edge and they all peered after it. Twenty feet below them an unruffled expanse of black water reflected the glow of light.

Sandy broke the stillness with his hoarse whisper. "Do you suppose they were in it when it went over?"

"I doubt it," Phillips said decisively. "They probably were just getting rid of a conspicuous vehicle. Smart move, of course. And handled smartly. Because if the car's disappearance should be traced to this spot, the conclusion would probably be just that-that Baron and his friend had disappeared too."

"I agree," Gonzalez said. "Our friends are not careless. They do not lose their heads. I think they do not lose their lives either."

"Then do you think they all plan to leave this place in the gray coupe?" Ken asked.

"And where are they?" Sandy added.

"Good questions," Phillips said. "Anybody got any answers?"

There was silence for a moment, and they all stared once more, as if fascinated, at the sight of the tire tracks that disappeared into nothingness.

There was no doubt at all that a car had actually gone over into the quarry pit, Ken was thinking. The edge of the pit between the tracks was slightly crumbled, where the undercarriage of the vehicle had scraped across it during the fatal plunge.

"I suppose," he said softly, "they may have seen us coming, and gone off to hide somewhere until we go away again. Unless they're very close, they wouldn't know who we are. I don't think any of us has been in the light-except the guide, here. If they think we're hunters, who just stumbled on the place, maybe they think we'll look around and then leave. Even if they think we're going to report the situation to the police, they might think we'd all go off together to do it."

"That is a possibility," Gonzalez said slowly. "There is certainly no use trying to hunt for men on foot in this rough country and in the dark. I suggest we accept Ken's premise temporarily. We will stare at these tracks a moment longer. We will all shake our heads sadly. We will look once more at the gray coupe. Then-"

"Listen!" Sandy broke in suddenly in a hoarse whisper. "I heard something!"

They all kept perfectly still for perhaps thirty seconds.

Then Gonzalez shrugged. "I don't-"

"Sounded like a car motor," Sandy insisted.

"Sandy's got ears like radar," Ken murmured. "If he says he hears something, there is something to hear."

"Oh!" Sandy let out his breath. "Just an airplane, I guess. I can tell now that the sound comes from up above somewhere."

"All right," Phillips said briskly, "if we're going to put on this act in the hope of luring them back here, how do we play the final scene? Are we going to drive both our cars away?"

"Exactly," Gonzalez said. He paused for a moment, in concentration, and suddenly they could all hear the faint throbbing sound that had caught Sandy's attention.

"The cars will return to the highway," Gonzalez went on. "Then, Mort, you and I and the policemen here will conceal ourselves at the bottom of that ravine."

Ken suddenly grabbed the Mexican's arm. "Is there a regular airplane route above us here? Do planes often cross this part of the country at this hour?"

Gonzalez stared at him for a moment, and in the silence the throbbing overhead grew louder. Then the Mexican turned swiftly toward one of the police officers who had accompanied them from the Antiguo Morelos station. He snapped out a question in which Ken caught the word aeroplano.

"No, Capitan." The answer was quick.

Gonzalez prodded with another question, longer and obviously more explicit.

The same answer was repeated. "No, Capitan."

"This is not a regular route. Planes pass over here very seldom." Gonzalez twisted his head to look up into the sky.

Ken spoke aloud the thought that had leaped to his mind. "They're not transferring to the gray coupe! They're transferring to a plane!"

This time Gonzalez snapped his question to the guide. The small man deliberated a moment and then shook his head.

"He says there's no place around here big enough for a plane to land," Gonzalez reported.

Phillips breathed his relief. "Good! We'd certainly have no chance to follow a plane."

But they warily listened for a moment longer. Now the throbbing seemed to fill the whole dark night.

"It's not a big transport," Sandy said. "Must be a single-motor job."

"There it is!" Ken said suddenly.

They all swung to look in the direction of his gaze. The sky was slightly clouded over. The dim starlights that patterned it here and there were all motionless.

"I saw a blue exhaust flame a second ago," Ken insisted. "See? Right there!" He pointed back toward the direction of the highway, and an instant later they all saw the faint blue blur he had noticed. It was heading toward them.

Sandy had been straining his ears. Now he said softly, "That's no plane! That's a helicopter."

"A helicopter!" Mort almost shouted the words. "Then it wouldn't need much space to land." He swung toward the guide but Gonzalez was already questioning the man in a rapid fire of Spanish.

This time the man didn't hesitate before he replied. Nodding his head vigorously, he pointed across the quarry to the top of the cliff that rose beyond it. The crest of the rock wall was faintly visible, a more solid black against the black of the sky.

Ken followed his pointing finger and then he swung back toward the direction of the throbbing sound.

"Look! A green flash!"

The stabbing green light went on three times, at short intervals, and then the sky in that quarter was completely dark again.

"It's a signal!" Ken exclaimed. "He must be getting ready to land."

The throbbing sound was almost overhead now, and still coming closer.

Ken looked again at the cliff toward which the guide had pointed. He was just in time to see a green light glowing there for an instant before it disappeared.

His hoarse cry brought the others around and they all saw the next two flashes of green from the cliff.

"That's the landing field all right, up there." Phillips spoke between clenched teeth. "We'll never get them, once they take off. Ramon!" He spoke rapidly, with his hand clamped around the Mexican's arm. "It's too late now-if they take off for the hide-out, we can't follow. The next best thing is to stop them before they leave. We'll at least get Baron and the money. Can we get to the top of that cliff?"

Gonzalez spoke swiftly to the guide and the guide nodded.

"Come on," Gonzalez told Phillips. "You too." He gestured toward the Mexican police officers and then repeated the order in Spanish. "Vamos!"

Phillips spoke directly to the boys. "You two are going to stay right here-and I mean it! Get in the sedan and keep out of sight!"

The guide had already started to move around the edge of the quarry. Gonzalez and the officers were trotting after him. Now Phillips joined them.

Ken and Sandy stood alone in the darkness. They had known better than to argue with Phillips in his present mood. If they had followed him, he would have turned back to see that they carried out his orders. And they had no right to make him turn back from the job that awaited him at the top of the cliff.

Silently they watched the jiggling beams of the flashlights grow smaller as they rounded the edge of the quarry. And then the beams slanted upward and they knew that the party had begun to climb the cliff along what must be a slanting path toward its top.

The helicopter had passed over them now-had gone beyond the cliff and was slowly circling back. Once more it flashed its green signal light, three times, and once more the green light on the cliff answered.

"A fine business," Sandy said disgustedly. "We get all the way here, and then-"

Ken broke in on him. "They'll never make it," he said. "Look."

The light from the plane and the light on the cliff had started a rapid exchange, flashing alternate signals in quick succession. Twice the beams formed a vivid green cross in the sky. The size of the cross showed that the ship was already close to the ground and descending at the rate of several feet a second in an almost perpendicular line.

"It's about to land!" Sandy breathed.

The slanting row of bobbing flashlights was still many long yards below the top of the cliff. And the boys knew that Phillips and Gonzalez, unable to see past the upper reaches of the cliff, had not yet realized the futility of their errand.

The green light on the cliff fastened firmly and steadily on the helicopter. No longer did it blink on and off. Now it held the hovering plane at the tip of a blunt shaft of light, painting its underbody a pale emerald. The shaft of light grew shorter. The helicopter was close to the ground.

And then the shaft of light disappeared altogether, transforming itself into a widespread pale-green blur. The helicopter had landed. The light blacked out entirely.

Faintly, from the cliffside below the plane, the boys could hear an enraged shout. One flashlight topped the edge of the cliff, and then another. Both swung to the right, where the green glow had showed a moment before, and then began to move rapidly toward that spot, still several hundred feet away.

Suddenly the helicopter's motor roar increased. It was impossible to see the plane actually springing up into the air, but the boys were clearly aware that it was already doing just that. And then one of the flashlights caught its whirling rotor for an instant and sparks of light glinted in the sky.

A spurt of fire flashed from the vicinity of the flashlights, and the sound of a shot reached the boys' ears. Another followed, slanted upward. Loud and sharp in the night, three more shots streaked after the first, each at a steeper angle than the last.

But the roar of the helicopter's motor remained steady. The darting flashlight beams ceased their frantic searching of the overhead darkness. One last shot barked out, and then silence fell.

"They got away!" Sandy's voice was a groan. "Two minutes sooner and-" He broke off with a gasp. Ken's fingers had closed around his arm with the grip of steel pincers.

"Quiet!" Ken breathed.

Sandy bent his head and caught the distant murmur of angry frustrated voices from the opposite side of the quarry.

"No," Ken breathed against his ear. "Nearby-something moving."

Then again, more clearly, he heard the sound that had first caught his attention-the sound of a hard-soled shoe coming down on loose gravel.

Sandy took a single cautious step forward, in the direction of the noise. Ken moved beside him. He remembered, grimly, that Mort Phillips had ordered them to get into the sedan. They had been too interested in watching the helicopter to obey, but Ken wished now that they were behind the protection of the sedan's metal body.

They were heading for the sedan now, and for the jeep that was parked in front of it. Another footstep sounded up ahead of them. But their own progress, over the soft dust of the loading area, was completely silent.

Ken tried to estimate their position in the darkness. He thought they must be very close to the jeep. He was certain that they had already passed the gray coupe.

Suddenly his outstretched hand touched cold metal. They had reached the jeep. Its front right fender was under his fingers.

One more footfall sounded, closer this time and to Ken's right. There was no doubt now. Someone was moving through the darkness, across the level space just in front of the jeep.

Guiding himself by his hand, and aware of Sandy's bulk close beside him, Ken moved a few feet until he could reach in toward the jeep's dashboard.

He couldn't afford to make a mistake. The slightest noise would reach the ears of the mysterious stranger who shared with them this level stretch of ground between the quarry and the steep-walled ravine.

Ken's fingers touched one button and hesitated. Cautiously, forcing himself to take his time, he felt above and below, to the left and to the right of it.

Yes, he told himself, this must be it.

He gave the button a sharp jerk and it moved away from the dashboard.

Instantly the jeep's headlights blazed alive, tearing a blinding white hole in the night.

Caught in their glare, heading across their path, was the figure of a man. He turned in mid-step and faced them, off balance for an instant. His face was dark and his black hair grew low on his forehead.

Ken recognized the man he had seen early that morning at the wheel of the gray coupe.

And then the man lifted his arm in a violent gesture and the gun in his hand spurted flame.

CHAPTER VIII

DEFIANT PRISONER

Blinded by the glare, the man shot wild. Ken could sense dust billowing into the air somewhere behind him as he dragged Sandy toward the rear of the jeep. Close together they crouched in the narrow space between the jeep's back wheels and the big sedan's radiator.

Even as they reached that dubious shelter a second shot spat out, and this one pinged shrilly against metal. The third hit its mark. The tinkle of glass and the glitter of flying shards told Ken, peering cautiously past the jeep's left rear fender, that die headlight on that side of the car had been shattered.

Thudding footsteps sounded then. Ken realized that the man was finally moving from the spot to which panic had momentarily rooted him. Now he was trying to escape the beam of the remaining light, instead of standing exposed in its glow while he tried to extinguish it by gunfire. He was moving to the left, Ken thought, into the area that had been illuminated a moment earlier by the now-shattered headlight.

Then two more guns spoke. Their roar was far away, but an instant later Ken heard the small dull plop of bullets striking dust-covered stone nearby. Phillips and Gonzalez, on the far side of the quarry pit, were reacting to the unmistakable danger signals of light and noise.

The thudding footsteps stopped long enough for a single answering shot, aimed toward the cliff. But almost immediately, as if recognizing the futility of finding such distant targets, the man started to run again.

"Don't let him get away!" Ken didn't know if Sandy had said the words or if he had shouted them inside his own mind. But he knew the big redhead was crouched behind him, ready to spring, as he got to his own feet.

His eyes were accustomed to the darkness now. He leaned boldly past the fender to watch the man sprinting toward him. The running figure wavered and slowed its pace when it left the glow of light and plunged into complete darkness. It angled away from the jeep and then angled slightly toward it again, as if the man were uncertain of his bearings. Obviously he was trying to escape the enemies which he must realize lurked in the neighborhood of the jeep, and at the same time arrive at the trail gouged out of the bank of the ravine. If he tried to reach the shelter of the ravine by any other route he would plunge headforemost down the steep bank.

Ken forced himself to wait until the shadowy figure was almost opposite him. Then he moved. His body catapulted forward, like a sprinter rising at the sound of a starting gun. He hit the man at the knees.

For a split second his momentum neutralized the forward drive of the runner. Motionless, they held their pose, the upright body arced over the nearly prone one, Ken's arms clamped around the other man's legs. Then the man gasped a single unintelligible Spanish word and raised the gun in his hand as if it were a club.

The heavy firearm was beginning its downward swing when Sandy's two hundred pounds struck home under the descending arm. The man toppled sideways like a falling tree. The gun flew out of his hand in a wide arc.

His head and shoulders struck the ground first, with a bone-jarring thud, just as the gun crashed on the jeep's hood. Then Sandy's weight landed astride his chest. Ken, groggy from the glancing blow of Sandy's knee, still clung grimly to the struggling legs. But he knew his grip was loosening.

"Hold him!" Ken gasped. The choking dust in his throat blurred the words.

"I've got him!" Sandy pinned the outflung arms to the ground, clamping a big hand at the angle of each elbow.

Thundering footsteps pounded toward them. A battery of blazing flashlights found the boys and their captive.

Phillips and Gonzalez reached them first. The police officers and the guide were directly behind. Through the murk of the dust they loomed like an approaching army.

"O.K.," Phillips panted. He glanced at Gonzalez. The Mexican policeman's gun was at the ready and he was already gesturing to the two officers. Phillips concentrated his own attention on the boys. With one hand on Sandy's shoulder and one on Ken's, he dragged them off the prone body. "You two all right?" he gasped, still breathless from his wild dash down the cliffside path.

"Sure," Sandy told him.

The two officers were hauling the captive upright, one on either side of him.

Ken stumbled getting to his feet but he managed to say, "Sure. We're fine. That's the driver of the gray coupe,” he added.

"I thought so," Gonzalez said grimly. He handed the two officers a pair of handcuffs.

Until now the driver of the gray coupe had not looked at any of the newcomers. Head down, dust-streaked face impassive, he had let himself be pulled erect without protest. But when one of the officers started to clamp the handcuffs around his wrist he jerked his head up, as if enraged at the indignity. And his glance lighted on Gonzalez.

His jaw fell and his eyes widened in panic. He babbled a few broken words in Spanish.

Gonzalez smiled. "Our friend here seems to think that I am a ghost. Apparently he believes the minor accident I suffered today could have had a fatal effect. Perhaps he hates to face the fact that he is a bungler."

But the driver of the gray coupe had recovered. He clearly surprised even Gonzalez when he said, in English, "You mistake me. You look much like a friend who died many years ago. And because I have just been attacked and beaten-"

Gonzalez interrupted him gruffly. "Take him to my car. We shall return to the post at Antiguo Morelos," he told the two officers. "One of you drive his car. The other can follow us in the jeep."

The clock in the police station said ten fifteen when they all entered the brightly lighted room, where, less than two hours before, the guide had showed them the location of the quarry road. Phillips, who had guarded the captive in the back seat of the sedan, during the return drive, handed him over to the two police officers.

Gonzalez directed them to take the man into a back room temporarily, until Phillips and he were ready to interview him. In the meantime, he ordered that the man's fingerprints be checked and he and his car searched thoroughly. Gonzalez added that he wished to see the contents of the prisoner's pockets as soon as possible.

Then he conferred briefly with the chief of police and finally he conducted Phillips and the boys into a small room whose door he shut behind them. They all sat down wearily on the stiff wooden chairs drawn up around a table beneath a single electric light bulb.

Gonzalez sighed. "Inquiries will be made in an effort to trace the helicopter through the aeronautics bureau. But I doubt if we can expect much help from that lead. However," he smiled faintly, "I have inaugurated another plan of which I am more hopeful."

"What's that?" Phillips leaned forward.

"I have sent word to the nearest restaurant to bring us arroz con polio as soon as possible."

Sandy, busy dusting his trousers, looked up with mingled interest and confusion. "A rose? From a restaurant? They wouldn't have anything more substantial there, would they?"

"Arroz con polio," Philh'ps told him, "is about as substantial a meal as even you could want, Sandy. In fact, it's almost a fitting reward for that little performance you two put on back at the quarry-despite my orders to stay in the sedan. It's chicken and rice, to be precise. The rice is done with saffron. The chicken-"

"Stopl" Sandy pleaded. "Don't tell me any more until I can see it right in front of me."

"And that should be in about twenty minutes," Gonzalez promised. "In the meantime-"

There was a knock at the door and one of the policemen entered with the items that had been removed from the prisoner's pockets. The moment he departed, Gonzalez spread them out on the table-a wallet, a ring of keys, a handful of coins, a pocket comb, a package of cigarettes, and a cigarette lighter.

When Ken's eyes fell on the last item he leaned forward eagerly. Weariness and the lingering effect of Sandy's accidental blow vanished from his face as he said, "Let's see if that lights with a green flame."

Gonzalez picked it up and pressed the lever. The flame that leaped up from the wick was a clear golden yellow. Ken sank back in his chair.

Gonzalez smiled at him. "You are young," he said. "You expect too much." He fingered the lighter. "This proves nothing. Perhaps it is only the guide who carries a green-flamed one." Then he opened the wallet and one by one laid out the items it contained. "Eighty-six pesos in bills. A calendar. An identification card." He read the last carefully. "According to this card our friend is a Luis Mendoza, of Avenida del Norte, number two hundred and twelve, Mexico City."

Immediately he summoned a policeman and issued instructions that the police in Mexico City be asked to check on Mendoza at that address. And he added that now he and Phillips wished to interview the prisoner.

Mendoza had completely recovered from the shock of seeing Gonzalez alive and well. He stood at ease before the table, hands in his pockets, a half-smile on his face.

"Since you are so proud of your English, that is the language we will speak," Gonzalez told him. "You do not seem so nervous now, Mendoza," he added.

Mendoza shrugged. "Why should I be nervous? I realize now that I am in the safe hands of the police. When I first tried to defend myself, back there, I think it is bandits who attack me."

"I see," Gonzalez said noncommittally. "And what were you doing at that old quarry?"

Mendoza looked surprised. "But it is a fine place to hunt deer."

"At night?" Gonzalez snapped.

"It is perhaps not the best sportsmanship." Mendoza pretended embarrassment. "I use a flashlight."

"And a pistol instead of a rifle?"

Mendoza smiled again. "It is because I realize the flashlight is unfair. It hypnotizes the deer. So I make it fair again. I use the pistol because it is more difficult to aim than the rifle." He glanced toward the door. "And now I may go-now that I have explained all? I am a poor and simple man, but I hope I have made everything clear."

"Oh, quite clear," Gonzalez said dryly. "Except for a few small things, perhaps. For example, why should a poor simple man like yourself force my car off the road into a gorge, and then go off leaving me for dead?"

"I? But Capitan is making a joke. He does not truly believe I could do such a thing."

"On the left front fender of my car," Gonzalez told him, "is a streak of gray paint, like the paint on your car, my deer-hunting friend."

"Ah?" Mendoza looked concerned and then said, "But this is no doubt a coincidence. There are many cars with gray paint."

"Quite so," Gonzalez agreed casually. "And probably a poor simple man knows little of science-has not even heard, perhaps, of the marvelous instrument called a spectroscope?

There was a wary look in Mendoza's eyes now, but he shrugged once more. "Even the word itself I do not know."

"Of course not. Therefore you do not know that this instrument can analyze the paint from your car and determine exactly what is in it. It can also analyze the gray paint rubbed off on my car and tell us if the two are exactly identical." Gonzalez leaned back and looked casually up at the man. "I tell you frankly, Mendoza, we have not yet put our spectroscope to work on the two cars. But what do you think? Will it show the two paints to be the same?"

Mendoza's eyes flicked once around the room, as if seeking inspiration. "But of course, Capitan," he said suddenly, "I see now. My fault is not to explain to you a curious incident that happened to me. A most mysterious incident. This morning I was at Nuevo Laredo, at the border. The Capitan knows this town?"

Gonzalez nodded silently, gestured to him to go on.

"While I am having breakfast in a restaurant my car disappears from the street where I leave it parked. But on a light pole, next to the place where my car once stands, is a message on a piece of paper. It tells me that I will find the car in Monterrey near the Alameda- the plaza."

"And you immediately reported this loss to the police, of course," Gonzalez said.

"But no, Capitan. I do not like to have dealings with the police-me, a poor and simple man. I go instead to Monterrey, to see if my car is there."

Ken and Sandy eyed each other, amazed at the obvious falsity of this tale. But Gonzalez remained cool and unmoved.

"I see. You simply travel the hundred and fifty miles to Monterrey. By bus?"

Ken and Sandy waited. If Mendoza answered Yes, his tale could be checked with ease. But Mendoza sidestepped the trap.

"Oh, no, Capitan. Some kind turistas-a man and his wife-gave me a ride to Monterrey. And there"-Mendoza's eyes opened wide as if in pleased astonishment- "there I found the car, just as the note tells me. It is a mysterious incident, no? And it explains to you why I was not in my own car between Nuevo Laredo and Monterrey."

"How do you know that's where the 'accident' occurred?" Ramon asked quietly.

Mendoza was ready for that too. "I only assume so, Capitan," he said quickly. "Because south of Monterrey I am driving the car myself, and of course I would never do such a thing as you have told me of."

"Very well." Ramon appeared to be completely satisfied with the amazing story. "Simply show us the note which was left for you, when your car was taken, and give us the name of the tourists with whom you rode to Monterrey, and all will be clear."

Mendoza shook his head sadly. "Alas I I did not keep the note. How could I know I would need it? And the kind turistas did not give me their name."

"In that case"-Ramon's voice was still quiet, but now the quietness had a deadly quality-"you had better give us the name of the man who told you to drive me off the road. Without his name, we may be forced to charge you, alone, with attempted murder."

Mendoza's face had paled, but nevertheless he smiled. "Now, indeed, the Capitan is joking. He knows he could not prove me guilty of such a charge." The emphasis he gave to that one word was deliberately arrogant.

Gonzalez did not reply. He merely gestured to the two policemen to remove Mendoza from the room.

Mendoza turned willingly to leave, but at the door he paused. "May I have my things?" He pointed to his possessions on the table.

"Later," Gonzalez said shortly.

"I understand." Mendoza smiled. "Probably you have other machines like this-this spectroscope, which you will use to examine them. But I assure you, Capitan, they are all innocent, like myself. Or have you not yet had time to discover that I am not a criminal-that there is no record of my fingerprints on file?"

As soon as the door had closed behind him, Sandy said, "He's not going to get away with that story, is he?"

"Who knows?" Gonzalez replied. "He is a cool one, eh? In a small second he invents a good story. And I am certain that there will be no record of his fingerprints, as he says."

"But-"

"Look, Sandy," Mort Phillips said patiently, "what we need is proof-not just a conviction in our own minds."

"In any case," Gonzalez said, "that accident is not of prime importance right now. I hoped I could scare Mendoza enough to make him talk-make him reveal his connection with the man in Baron's car." He shrugged. "But you saw how much I scared him-and how much he talked. We will question him again later, and perhaps some small candle will light up in our minds-"

"Candle!" Ken repeated the word suddenly, so excitedly that the others turned to stare at him. He was clutching Sandy's shoulder. "Remember that old magician's kit we found up in your attic?"

"Sure," Sandy said blankly. "The one I used to play with when I was a kid. But-"

"Weren't there chemicals in there that changed the color of candle flames-made them red or blue or green?"

"That's right." Sandy was still completely confused by Ken's questions, and the others were equally at sea. And then suddenly Sandy got it. "Green! Sure-I could make a green flame by putting a little of one of the chemicals on a candlewick."

Ken was already reaching for the lighter, but he paused before he touched it to ask Gonzalez' permission. The Mexican nodded, eying Ken intently.

"Naturally they wouldn't want their lighters to burn with green flames all the time," Ken said, as he carefully examined the small object. "That would be too likely to call attention to them. But if they carried a little bit of that chemical, they-"

Sandy was now peering over his shoulder. "Take the filler plug out," he urged.

Ken removed the small screw, using a thin coin as a screw driver. He sniffed at the cotton stuffing inside. "Smells like ordinary lighter fluid to me," he admitted, but as he spoke he turned the screw over and revealed the small cap attached to its underside. Beneath that cap, Ken knew, should be a spare flint or two.

Slowly he unscrewed the cap and tapped it over the palm of his hand. No flint fell out. He turned the cap over and peered into the tiny hole in its center. "There's a pasty white stuff in here," he muttered, trying to control his eagerness. "I think we could get it out with a pencil."

"Let me try it," Sandy said. "I remember now how I used to do it."

With the other three gathered close around him, he picked up a small dab of the paste on the point of a pencil and transferred it to the lighter's wick. Then he snapped the lever.

Flame leaped up-a brilliant green flame.

"Magnifico!" Gonzalez said. "Magnificol" And Mort Phillips pounded both the boys on the back.

The green flame burned for half a minute and then slowly changed back to its normal yellow.

Gonzalez burst into machine-gun Spanish and Phillips listened to him, nodding his head constantly in agreement. Then Gonzalez turned to the boys. "You will please fix the flame again, as before?"

"Sure," Sandy agreed. "But what's it all about?"

"You will see." Gonzalez rubbed his hands with satisfaction.

He looked the lighter over, when Sandy was finished, to make certain it showed no signs of having been tampered with. Then, replacing it on the table, he stepped to the door and asked the policemen to bring Mendoza back again.

"Mendoza," Gonzalez said solemnly, when the blandly smiling face was before him once more, "I will tell you what we will accuse you of-the charge you will face. We know there is a group of bandidos here in Mexico who provide a hiding place for criminals trying to escape the law. The two men who were picked up by the helicopter tonight were going to that place. You helped them. You are part of the gang. We know a great deal about your associates-even little things, such as the fact that they use lighters that have a green flame. This green flame is a recognition symbol. So we will soon pick them all up-and you will all be charged with aiding criminals to escape the law. You personally, of course, will also be charged with attempted murder."

He leaned back calmly, waiting for Mendoza's reaction.

"There are several things wrong with what you say, Capitan," Mendoza began, almost apologetically. But his voice regained its deliberate arrogance as he spoke. "First, you cannot know very much about these bandidos, or you would not be hoping to obtain information about them from me, a poor and simple man. You would know I have no information to give. Second-and this proves my first point-you already have undoubtedly tried my lighter, and learned that it burns with an ordinary yellow flame, like any other. So why, Capitan, do you make to me these strange statements about charging me with crimes I have never heard of?"

"All right, Mendoza. You have had your chance. Take him back and lock him up," Gonzalez ordered coldly. "You may have your cigarettes now and your lighter," he added. "You may want them. You will be here a long time."

Mendoza took the two items from the table. Insolently he flipped a cigarette into his mouth. "Perhaps not so long as you think, Capitan," he said. He lifted the lighter and pressed the lever.

Four pairs of eyes watched his face fixedly.

The green flame flared up.

Mendoza gasped. Swiftly he blew the flame out with a puff of breath. For an instant he looked panic-stricken.

Then, with a visible effort, he pulled himself together. He pressed the lever again, quietly, and let the emerald-colored flame burn.

"You are clever, Capitan," he said. "It probably was very easy for a clever man like yourself-who knows of spectroscopes and other such scientific things-to put something in my lighter that makes it burn with a green flame. But I am not afraid. I know a jury would believe that you know far more about such tricks than a poor simple man like myself." He lighted his cigarette then, calmly, and walked out of the room.

The man who entered, immediately after Mendoza's departure, wore a white apron and carried a huge tray. "Capitan," he inquired, "you ordered arroz con polio?"

"Si, si. Put it here." Gonzalez looked tired and defeated, after the unsuccessful attempt to crack Mendoza's pose of innocence. But he tried to smile at the boys. "Perhaps after we have a good meal we will be able, for a change, to have an idea that works, eh?"

"A thousand pardons," the waiter was saying, as he put down his load. "But the cook is sick and unable to prepare the arroz con polio. And so I bring you instead, Capitan, a fine soup which I made myself by opening cans. Six cans, Capitan!" he concluded proudly.

Gonzalez brought his fist down on the desk with a mighty crash. "This," he said fiercely, "is too much!"

CHAPTER IX

THE EMPTY TRAP

The soup was hot and filling, however. The rolls served with it were light and crusty. And there were a large pot of coffee and a pitcher of hot milk.

By the time they had all poured themselves a second cup of coffee, the mood around the table was slightly less grim. Mort Phillips wrote out a brief report to be telegraphed to his superior in Washington, and seemed relieved when he had finished the unpleasant task of confessing that Baron had slipped through their fingers. Gonzalez sent for somebody to transmit Phillips' message, and the officer who came at his call returned a moment later.

"Mendoza's fingerprints are not on file as a known criminal," he said. Then, as Gonzalez nodded grimly, he handed the Federal officer the report that had just arrived from the Mexico City police.

"Gracias." Gonzalez scanned the paper quickly. "Ah-hah!" he said. "Very interesting. He has not lived at that Mexico City address for more than a year. Mendoza's landlady was glad to see him leave. She says he was a no-good one, always behind in his rent and with no regular job. But he paid her all he owed just before he left. She thinks he suddenly obtained a great deal of money. He seemed very much pleased with himself, she says. And he asked her to send his mail to his new address-Lazar Street, in the town of Rio Claro."

Even before he finished telling them the news he was on his feet, striding toward a large map tacked to one wall of the room.

The others followed him eagerly. "Is Rio Claro near here?" Sandy asked.

"It is on a road that runs west out of this place," Ramon Gonzalez said. "There." He pointed to the name on the map. "About a hundred kilometers away."

"Only an hour and a half's drive," Sandy said.

"No, my friend," Gonzalez corrected him. "The hills and valleys of that road are not for racing. The trip will take nearly twice that long. But," he added more cheerfully, "Rio Claro itself is in these same hills. It is wild country-an excellent place for a hide-out."

"Then maybe we're getting some place," Phillips said. There was a new optimism in his voice too. "If Mendoza works for this outfit, it seems reasonable that he would live near its establishment."

"Maybe he lives right at it," Sandy said. "Maybe that address-what was it? Lazar Street?-is the place we're looking for."

Phillips laughed. "I doubt it. It's not going to be that easy, I'm afraid. If he left that address with a landlady, it means he's not afraid of having it known."

"I suppose you're right," Sandy admitted. "But don't you think the hide-out might be in Rio Claro somewhere?"

Gonzalez shook his head. "That is unlikely, I think. It is a small town, of some five thousand inhabitants, and the local police would surely have noticed anything out of the ordinary there. But it is clear that we should go to Rio Claro, at any rate. I think the hide-out is, perhaps, somewhere nearby. And in Mendoza's house- who knows what clues we may find, eh?"

"We can stake the place out," Phillips said.

"If that means-as I think-to keep it under surveillance-" Gonzalez smiled- "I agree with you."

"That's what it means." Phillips grinned briefly and then looked thoughtful. "By now, I should think, the men in the helicopter will have reported that somebody was at the quarry. They must have seen our lights and probably heard the gunfire. But they won't have any way of knowing, yet, who we were and whether Mendoza tangled with us or not."

"But I'll bet they're plenty worried," Sandy said. "So they'll probably send somebody to Mendoza's house pretty soon to see if he returned safely." He looked at his watch. "If Mendoza had gone straight from the quarry he couldn't have reached home for another half hour yet, so we're probably in time to get up a guard."

"Exactly," Phillips said. "I suppose you'll want to get through to Rio Claro and put somebody on guard there right away?" He looked at Gonzalez and the Mexican nodded. "But let's not waste any time getting there ourselves," Phillips added. "It would be fine if we could be on hand to watch that somebody arrive. By 'we,'" he said, speaking specifically to the boys, "I mean Ramon and I. You two-"

"Oh, now look!" Sandy began.

Ken grinned. He had expected this. "Mort's right, Sandy," he said. "We're just tourists-remember? But I've been thinking, why don't we change our plans? Why don't we make a little side trip to Rio Claro? I hear the country's beautiful around there."

Sandy grinned too. "That's a great idea! After all, there's nothing to stop us. Mexico wants tourists to see the whole country, not just-"

"All right. All right," Phillips gave in, while Gonzalez, already at the door, looked back at them, half amused and half concerned. "Come along as far as Rio Claro," Phillips continued. "But you've got to promise me that you'll follow whatever advice we give you there, about staying out of sight when we ask you to."

The boys gave him their word on that.

Gonzalez stepped into the outer room to get in touch with the Rio Claro police. They could all hear his conversation through the open door. He asked first if Mendoza had a phone and was told, after a brief pause, that he did not. Then he asked if there had ever been any reason to suspect the man of illegal activities. There was a pause then during which Ramon explained that they were consulting the policeman in whose beat Mendoza lived. The reply when it came across the wires was that little was known of Mendoza. He seemed to be a quiet man who lived alone with an elderly housekeeper. Apparently his business required him to travel occasionally, because he sometimes left town for several days at a time. But when he was in Rio Claro he stayed to himself, remaining in his house most of the time and not involving himself in local matters or local social life. Gonzalez asked that an unobtrusive guard be stationed near Mendoza's house immediately, and made arrangements to meet the officer who knew Mendoza's neighborhood best, at a certain corner near the outskirts of town.

"We expect to arrive in Rio Claro within three hours," he concluded.

While he conferred briefly with the Antiguo Morelos chief, after he hung up, Ken voiced to Phillips an idea that had just come into his mind.

"I've been thinking that there might be a way to bait the trap at Mendoza's house," he said slowly. "If his car were left parked in front of his house, wouldn't that help to confuse anybody who came looking for him? They would assume at first that Mendoza himself had brought it back, and then-"

Gonzalez re-entered the room just then and Phillips said quickly, "Listen to this, Ramon. Ken's just had a good idea. Tell him, Ken."

Gonzalez smiled when Ken had finished. "I, too, think it is a good idea. Bueno. We shall take the car with us. And it is time to organize our journey, no?"

It was agreed that Sandy should go with Gonzalez in the gray coupe, and that Ken and Phillips would travel behind it in the boys' convertible.

Shortly after eleven o'clock the two cars moved away from the police station of Antiguo Morelos and turned westward a short distance down the highway. The smooth paved road seemed level enough for the first mile or so, but suddenly it began to twist and squirm its way up a mountain.

"Hang on," Phillips said grimly. "This is just the beginning." He was at the wheel, and Ken was glad not to be driving through this particularly difficult stretch of Mexican terrain. The taillights of the gray coupe, up ahead, were seldom visible for more than a few seconds at a time before they disappeared around another of the interminable curves. But even in the darkness Ken could see that the country was magnificent, and he promised himself that some day Sandy and he would return and drive along this road in daylight.

The weather had been comparatively warm in Antiguo Morelos, even at that late hour of the evening. But when they had been traveling for less than half an hour Ken was reaching for his jacket and closing the window. The road was climbing high into the chilly altitudes. And it continued to climb, with occasional dips for variety, for what seemed to be endless hours.

In fact it was ten minutes to three when, at the foot of one of those brief zigzagging descents, they came into the town of Rio Claro. Immediately the highway pavement became the rough cobblestones of a city street. At the first intersection, just beyond the glow of a street light, Gonzalez pulled to the high curb and stopped. A man in uniform emerged from a doorway in one of the long row of silent darkened houses and stepped over to the gray coupe.

Phillips parked just behind, and he and Ken climbed stiffly out of the convertible and walked forward to lean on the door on the driver's side of the coupe. Gonzalez introduced them to young Pedro Montez, who was bending low to address himself to those seated inside the red car.

"Montez covers a beat in the part of Rio Claro where Mendoza's house is located," Gonzalez explained rapidly. "He tells us that a fellow officer is already on guard at a window opposite Mendoza's house-the same place we shall use for our own-how do you say? -stake out." At Phillips' nod he added, "He also tells us that he paid a call at Mendoza's house tonight, to see what he could learn." He turned his head to nod at Montez. "Good work, Montez. Now tell us what you learned during this visit."

Young Pedro Montez spoke concisely and to the point. "Not very much, Capitan. I spoke to his housekeeper. She was still awake, because she enjoys listening to the late music broadcast by the Rio Claro radio station. And she was not angry with me for disturbing her, when I explained that I was seeking a lost dog, because she likes dogs. I was not lying, Capitan," he added with a brief smile. "In Rio Claro are many dogs, and each night I am seeking one or perhaps two dogs that have become lost."

After that apologetic digression he hurried on. "She knew nothing of the dog, but she was not unwilling to talk a little. She lives very quietly herself. And her employer also lives quietly, she says. Often he is out of town for many days. He is out of town now, she says. But she expects him to return home in time for breakfast. He seldom has visitors-in fact, she could remember none at all during the year he has lived here. This seems strange to her, but she is not really interested. Where there are few visitors, she says, there is little work. And only one other thing about Mendoza seems strange to her. His house is a new one, with a garage that opens directly from the sidewalk. But Mendoza never uses it. He parks his car always in the street. She thinks he likes maybe to show it off. And she thinks this is foolish as well as strange, because it is not such a new car that a man should be so proud of it."

Pedro Montez was a young man, and his eyes were bright and intelligent beneath his visored cap.

Gonzalez nodded at him approvingly, and there was silence for a moment as they all considered the young officer's report.

Sandy, trying to stretch in the cramped quarters of the coupe, broke the silence of the night with the sound of a dull blow as his fists struck the dashboard. "Sorry," he muttered apologetically, lowering his arms so that they could extend full length beneath the dash. "Ouch!" he said loudly.

"Sandyl" Phillips cautioned. "Keep it quiet."

"Sorry," Sandy said again. Now his fingers were gingerly exploring the underside of the dash. "He's apparently holding his not-so-new car together with a paperclip.”

"With a what?" Gonzalez asked curiously.

Ken, leaning on the door on Sandy's side of the car, pulled a tiny flash from his jacket pocket and thrust the light on. "That's right," he said. "It's a spring-type paper clip, held on here with a suction cup. Maybe it's-" He stopped suddenly. What he had been about to say as a joke struck him as a possible serious truth.

"Maybe," he said slowly, "this is a sort of post office for Mendoza and his friends. He has no phone. He never has visitors. And he parks his car in the street instead of in his garage. So maybe he sends and receives messages this way. Anybody passing his house could open the car and remove a note, or leave one."

There was a long silence. Gonzalez broke it. "Bueno," he said softly. "Muy bueno. Which means," he translated with a smile, " 'Good. Very good.' In fact, very good indeed. I am glad you two came with us to Rio Claro-no, Mort?"

Then his voice picked up speed. "Now we shall really bait the trap, no? And we shall be able to see if someone comes to nibble at the cheese. Quickly. Let us establish ourselves."

For a few more minutes he conferred with young Pedro Montez, and then his plans were complete. Phillips, with the two boys, were to take over the watch in the upper room of the house directly across the street from Mendoza's. The owner of the house was an aunt of Pedro Montez and she had agreed to this arrangement for her nephew's sake. Gonzalez, after parking the gray coupe in front of Mendoza's house, would watch from a vantage point outside, in a narrow passageway that ran alongside the same house where Phillips and the boys would be stationed.

Five minutes later, after the convertible had been parked safely behind the Rio Claro police station, Pedro Montez led Phillips and the boys upstairs in his aunt's home to a neat bedroom, floored with red tile and containing one huge bed. The officer already on duty there, stationed at the big window hung with a Venetian blind, sprang to attention and reported that no one had entered the Mendoza house since Pedro Montez himself had left it. Then Montez assured them that his aunt would provide breakfast for her unexpected guests, and he and his fellow officer departed.

Phillips and the boys stood together at the window for a moment. Through the slits in the blind they could see Gonzalez parking the gray coupe just across the street, sliding out of the car, and melting away into the darkness. The trap was baited. In the paper clip under the coupe's dashboard was a blank sheet of paper which Phillips had torn from his notebook and which Gonzalez had slipped into place. The paper was carefully folded to conceal the fact that it was blank. There was nothing to do now but wait to see if anyone came to spring the trap.

"Of course," Phillips said finally, "our victim may not come until tomorrow night-if he ever comes at all. So why don't you two get some sleep?"

"But you-" Sandy began.

"Don't worry about me," Phillips assured them. "I'm used to round-the-clock vigils."

Neither Ken nor Sandy attempted to argue further with him. The bed looked enormously attractive. Within ten seconds both of them were asleep.

The next thing they knew they were simultaneously leaping into wakefulness, roused by an explosive bang. As Ken came to his feet he asked, "Was that a gun?"

The room was filled with a hard early-morning light. Phillips stood at the window beside a second figure, shrouded in a serape. It was a moment before the boys recognized the man as Gonzalez.

"Relax," Phillips was saying wearily. "It's just an elderly truck backfiring its heart out."

Yawning widely, both the boys joined the men at the window. Ken's watch pointed to seven thirty. "Nothing happened?" he asked

"Nothing," Phillips said. "And now that it's light we don't really expect any action. It looks as if we're going to have to wait out another day. Ramon just came up to join me for breakfast," he added, pointing to a loaded tray on top of the bureau.

Sandy automatically reached for a roll, but Ken resisted the idea of food. What he really yearned for was more sleep. But having reached the window he automatically glanced downward.

The noisy truck was in sight, bucking and jolting over the cobblestones and backfiring at irregular intervals. It came to a final halt directly below them, almost in line with the gray coupe opposite. Instantly the driver, muttering audible complaints, jumped from his cab and jerked up its battered hood. He was poking gingerly inside when a second, newer truck braked to a stop behind him, unable to pass in the narrow street. The newcomer's horn tooted loudly. The driver of the stalled vehicle shouted an angry reply.

Gonzalez was chuckling. Phillips leaned forward for a better view. Within a few brief seconds the street below had become a noisy bedlam.

A loaded bus had added itself to the halted procession and its driver and several passengers were climbing down to gather around the broken-down truck and offer eager advice. Six laden burros and their two masters approached from the opposite direction. The masters, brandishing leafy branches which they used as switches, entered the general discussion with enthusiasm. The burros began placidly to crop at the stalks of grass growing between the cobblestones. A handful of children appeared out of nowhere, bright-eyed and curious. Several doorways along the street opened and women emerged with brooms, ostensibly to sweep the sidewalk but obviously interested in the lively argument now joined by all of the men present. More passengers alighted from the bus and surged forward. Two boys on bicycles, balancing huge flat baskets of rolls on their heads, casually braked their machines to a halt and walked to the broken-down truck, still carrying their big burdens.

"In Mexico," Phillips told the boys, "every breakdown becomes a fiesta-a fine free-for-all."

Gonzalez, above the remarkably effective disguise of his enveloping serape, said, "But of course. We Mexicans are masters of the art of finding fun and excitement in trifles."

The argument in the street was now reaching a peak. Each participant clearly had his own idea of what should be done, and was willing to suggest it over and over, paying little or no attention to the ideas expressed by anyone else.

Ken pushed closer to the glass. The broken-down truck was piled high with firewood, completely concealing the gray coupe beyond it. "We can't see Mendoza's car at all," he muttered. "This would be a fine time to-"

"What fools we are!" Gonzalez was already sprinting for the door, his serape flying out behind him.

The engine of the broken-down truck roared into life just as Ramon's feet began to pound down the stairs. The driver banged down the hood, grinning widely, and leaped back into his cab. There were loud laughter and joking shouts of congratulation from the crowd. The truck lurched forward just as Gonzalez emerged from the house.

For a moment the truck could make little progress. The burros were in its way, and it was necessary for their masters to wave their switches menacingly, and to prod them with their hands and elbows, before they moved at all.

Ramon was trying to cross the street, but the crowd good-naturedly buffeted him from every side, holding up his passage. There was a general movement to follow the crawling truck, and for a moment Gonzalez was carried along with it. Then the truck suddenly swung around the last of the burros in its way and roared down the street. The second truck, behind it, followed immediately. Gonzalez was unable to duck in front of it. And he was foiled in his attempt to detour around its rear because the bus was also in motion by then, following the other two cars.

But finally Gonzalez broke free and raced to the gray coupe. An instant later, from the far side of the street, he gave one black angry glance up toward the window.

Its meaning was all too clear. The paper hidden in the clip beneath the dashboard was no longer there.

CHAPTER X

ON THE TRAIL AGAIN

Ten minutes later all four of them-Gonzalez and Phillips, Sandy, and Ken-reached an ancient stone building facing the Rio Claro plaza. Gonzalez led the way through the wide doorway and across the stone-paved courtyard inside to the room directly opposite. The fortresslike structure was the municipal building, and the room they were entering was the office of the local chief of police.

Gonzalez had already used Sefiora Garcia's telephone to speak to the chief-while Ken and Sandy and Phillips gulped cups of milk and coffee-and the chief was waiting for them. Phillips, trying to control the anger he felt at their failure to notice the person who had taken the paper from Mendoza's car, briefly translated to the boys the points which Gonzalez and the chief covered in their rapid discussion.

Scouting planes, which had reached Rio Claro that morning at dawn, and which had been circling the whole surrounding area ever since, were now moving in to circle the town itself. Pedro Montez, the young officer the boys had met the night before, was out with a small crew whose purpose was to locate the truck which had caused the apparently purposeful traffic jam before Mendoza's house.

"If the truck is still in the city, they will find it," the chief promised. His hair was black, but there were deep lines of age in his seamed and leathery face. "Do you want them to arrest the driver?" he added.

Gonzalez and Phillips answered with a firm "No!" almost simultaneously.

"What we want to do," Gonzalez went on to the chief, "is to learn where the truck goes. Perhaps it may lead us directly to the place we search. If it leaves the city, we will radio word to the scouting planes and they can follow its course into the hills. In this dry weather any vehicle traveling along the small unpaved roads will stir up a cloud of dust that can easily be detected from the air. And if the truck goes out of town along the paved highway, our motorcycle patrols will spot it."

"You're sure the truck breakdown was a deliberately planned incident?" Ken said.

"Do you ask me to believe that it was just a coincidence that the truck stalled directly in front of the car we were watching?" Gonzalez stared at Ken through the cloud of smoke from the thick cigar clamped between his lips.

"It didn't look like a coincidence," Ken admitted. "But why should anybody go through all that hocus-pocus? If they knew you were watching the place, they must also have guessed that you're holding Mendoza. And in that case they would know that any note in the car was a phony and not worth picking up. But if they don't suspect anything at all-if they assume Mendoza is still in the clear-why not just follow their usual custom? They probably don't always stage a performance like that when they want to collect a message left in the paper clip."

"I think the whole business was just one more proof that this gang is smart," Phillips said grimly. "They don't take chances. I don't think they can know anything definite about Mendoza's arrest yet, but they do know there was some sort of trouble last night as the helicopter took off. So they probably reasoned that any note left in Mendoza's car last night might be bait in a trap. They had to get it, in case it was a legitimate message. But they wanted to get it in a way that would cover their tracks."

Ken nodded. "And now, of course, they do know it was a trap because all they got was a blank piece of paper."

"Exactly," Gonzalez said. "And that is the reason we now wish to move very quickly, because they are already alerted to danger."

The telephone rang and the chief gestured to Gonzalez to accept the call. Gonzalez scooped up the phone and listened briefly. When he put it down he explained that Pedro Montez had traced the truck. It was now unloading its cargo of firewood at the rear entrance of the Virrey Hotel. "He will let us know the moment it leaves that place," Gonzalez said. He shook his head with reluctant admiration. "The hotel expected the wood to be delivered this morning. They are indeed clever, these men. They are careful to use a truck which has a legitimate purpose in town today-not one whose very presence would be suspicious."

"Does that same truck bring wood to the hotel regularly?" Phillips asked.

Gonzalez nodded. Young Pedro had checked that fact too. "But the hotel management knows nothing about the driver. He is simply a man who offered, a year ago, to deliver firewood regularly, and he has appeared once a week since. Apparently he lives somewhere in the hills outside of town, but the hotel does not know where."

"The hotel itself couldn't be the hide-out, could it?" Ken asked.

Before anyone could answer him, a knock sounded on the chief's door and a moment later a small, elderly man entered with two huge ledgers. The chief performed courteous introductions. The little man was the municipal tax collector and he had brought his records to the office at the suggestion of Gonzalez. Gonzalez immediately explained to him that they wished to know about all the buildings in the town which might conceivably be used as headquarters for a criminal hide-out. It would be a fairly large building, Gonzalez pointed out, big enough to accommodate several persons and an adequate staff of servants. It would also, Gonzalez added, be a comfortable-probably a luxurious-place. The men who employed the services of the hide-out undoubtedly could afford the best and expected it.

At first the little man was indignant at the possibility that the town of Rio Claro might harbor such a place, but Gonzalez skillfully smoothed his ruffled temper and urged him to compile a list of the buildings meeting the requirements he had outlined. Still looking somewhat insulted, and rather sleepy, the little man sat down at a desk with his two big books.

"Do his records cover the countryside outside of town?" Phillips asked.

Gonzalez shook his head regretfully. "But the job is worth doing, nevertheless. I do not believe the hide-out is here, as I have said before. From now on, however, we too will miss no chances. Eh? As to the tax records for the country about here-I am told it would take weeks to go through them, and that in any case they are doubtless not very accurate."

"I can see the advantages of locating a hide-out out in the country," Ken said hesitantly, "but wouldn't it have disadvantages too? You said it probably was a luxurious place. Would it be easy to get luxuries out there-things like electric current for pumps and refrigerators, for example?"

"Why not?" Gonzalez shrugged. "They could use a gasoline-engine generator. Ten barrels of gasoline would keep it going for a month, and they could truck that in even over a bad road-or use burros if neces-saiy."

"I suppose so," Ken said. "But a big modern house like that, even in isolated country, would certainly be noticed by somebody, wouldn't it?"

"It probably is not a modern house," Gonzalez said. "This was silver mining country, in the old days of the Spanish conquistadors, and wherever there were Spanish silver mines there were always haciendas-estates for the Spanish owners or managers. The buildings were like the one you are in now-stone walls several feet thick. Such walls stand for years. This municipal palace was once such a hacienda. It is perhaps three hundred years old. It costs money to make such a building modern and habitable," Gonzalez admitted, "especially if it has been abandoned for a long time, as have many of the haciendas in the hills. But if one has money, it is quite possible. From the outside, such a building would look ancient and uncomfortable. But inside it could be as modern as one of your big hotels." He looked at Phillips. "I think, Mort, that we shall discover that this is what our friends have done."

Suddenly they all became aware that the little tax collector had come to his feet, holding in his hand a sheet of paper. He straightened his rumpled coat and with a nod of apology to the others launched into a long speech in Spanish directed toward Gonzalez and the chief.

When he had finished, he handed Gonzalez the paper, accepted his thanks gravely, and departed with his two heavy ledgers. His records showed that only one business establishment and seventeen private houses in Rio Claro, which was not a rich town, even approached the qualifications Gonzalez had described. All seventeen were listed on the sheet of paper, together with the tax collector's own statement that he had known the resident-owners of those houses for the twenty-seven years he himself had held office in the town, and that he could personally vouch for their honor and their integrity.

The chief of police himself spoke up at that point, to add his own statement to that of the tax collector. He, too, knew all those houses well, he said, and could vouch for the fact that they were indeed what they seemed-homes of families who had lived in Rio Claro for several generations.

Ken remembered the unanswered question he had asked some time before. "But what about the hotel?" he queried.

"The hotel is the one business establishment on this list," Gonzalez said. "But both the tax collector and the chief of police vouch for that too. It was once a Spanish governor's palace, and the same Spanish family has lived there since it was built. When it became a hotel a few years ago, the owner of the house simply became the hotel manager."

The chief of police said something, half under his breath, and Gonzalez smiled at him and shook his head. "He thinks we may doubt his word, but I assured him we have complete faith in his knowledge of this town and his integrity."

The phone shrilled again and Gonzalez picked it up in the middle of the first ring. He listened for a few moments and then hung up with a brief "Bueno." To the others he said, "The truck is now empty. The driver is being paid for the wood. In a moment he will leave. And when he departs from Rio Claro he will lead us, I think, to our goal."

He got up and moved to the map on the wall and the others joined him there. Gonzalez pointed out the location of the hotel, on one of the streets leading out of the town plaza. They all studied the map tensely, with particular attention to the various small roads threading their way out of Rio Claro into the surrounding hifl country. The big clock on the wall ticked off the seconds, one by one.

At the end of three long minutes the phone rang once more. Gonzalez grabbed it, and stood facing the map as he listened to the quick rattle of Spanish over the wire.

"Si," he muttered. "Si." An instant later the phone was back in place and Gonzalez was pointing to a line that ran northwest out of the network of Rio Claro's streets.

"The truck is on this road," he said, "heading out of town. The road goes up here-you see?-through the village of Pino and the village of La Plata. Then it climbs this ridge and goes to the village of Gallego, in the small valley beyond. There the road curves eastward over to Leon, swings abruptly southward, and returns to Rio Claro. Very interesting, no?"

Mort Phillips nodded. His eyes were narrowed with intensity. "Very interesting indeed. A loop road, leaving Rio Claro at one point and returning at another. And about"-he calculated quickly-"twenty-five miles in total length."

"Exactly," Gonzalez agreed. "And in all the thousands of acres of wild, little-known country through which the road passes there are only four small villages. What better place for a secluded establishment, eh? Its nearest neighbor could be miles distant-and yet it has two exits for use in case of emergency. Most roads that go back into unpopulated hill country, like this, are dead-end roads, easy to block off, easy to watch. But this road-ah-hah! It is just the sort of place we should expect our friends to choose. Quickly, now-let us organize ourselves."

He and Mort and the chief conferred together for several moments, planning road blocks for each end of the loop, and naming the personnel of the two parties that would enter the road from either end. Phillips would head one such party, Gonzalez the other. And the scouting planes would remain in the air, in case the residents of the hide-out, alerted to approaching police forces, attempted to escape by their helicopter.

The chief hastily summoned deputies to fill the complement of forces demanded. He was clearly flustered by the importance of Gonzalez and Phillips, and unaccustomed to being involved in a search for dangerous lawbreakers. The annual Red Cross parade of Rio Claro was to take place that day, he explained, and he usually assigned his full force to that event. Normally a parade was the heaviest strain ever imposed on Rio Claro police. But today he would assign only two men to the parade. He himself would remain at his post, to await messages from Gonzalez and Phillips. And his other two officers, including young Pedro Montez, together with the dozen deputies he had called in, would provide the road-blocking and searching parties that were now being organized. Four men made up each road-block group. Phillips and Montez and two deputies would enter the loop road at the northwest corner of town. Gonzalez and a party of three would enter it at the other end.

Both parties would be armed. Both would receive radio reports on the truck's progress. No person or vehicle would be allowed to leave the road, once the search parties had started toward each other. And the two groups would remain in constant communication, so that if one discovered the probable site of the hideout, the other could join it for the final purpose of surrounding and entering the place.

Gonzalez and Phillips both had the quick efficient air of well-trained men, but the tension in their manner betrayed their belief that they were approaching the end of a long and important job.

Neither Ken nor Sandy mentioned the fact that their names had not been included on the hastily drawn-up rosters of road-block groups and searching parties. They knew that they were going to be forced to remain safely in Rio Claro.

But Ken said finally, in the brief lull when the cars were being drawn up outside the municipal building, "Mort, we still hope to have this story. Can you let us have the facts as soon as possible?"

Mort Phillips grinned at them both. "That I can do," he promised. "You deserve them and you'll get them at the first possible moment."

Gonzalez joined them. "I suppose you think it would be fun to come with us, eh?" He shook his head. "I think perhaps this will not be fun. If we find the men we seek, they will not be glad to see us. They will make us very unwelcome-very unwelcome indeed. Still, if you wished to take the risk, I should be willing to let you come along-except for a very selfish reason. If one of you suffered a small hurt-the prick of a cactus, perhaps, or the prick of even a tiny bullet-ah, poor Ramon! Then I would no longer be a capitan. I would be patrolling a jungle somewhere far away."

"We understand," Ken assured him, grinning. "And we're not going to plead to be taken along. But Mort has just said we could have the story as soon as possible. Is that all right with you?"

Gonzalez put an arm briefly around each of them. "I will be torn to bits by the Mexican reporters," he said, "but I will, nevertheless, see to it that you have the story first." He drew himself up. "I, Ramon Arturo Fernandez Gonzalez, promise you this thing."

The cars were ready to leave. Ken and Sandy shook hands with Phillips and Gonzalez and wished them luck.

"Walk around the town-take a look at Rio Claro while you're here," Phillips advised. "Don't sit around here waiting to hear from us. This may take quite awhile."

"We'll walk around long enough to find Sandy some breakfast, anyway," Ken assured him. "But we'll be back here by"-he glanced at his watch and saw that the hour was exactly eight-"ten thirty, in case you phone in. If we can join you out there when you get things under control, will you let us know?"

"Absolutely. And we'll get word to you as soon as possible-after ten thirty." With one last gesture Phillips was gone.

The chief rushed out to the cars to report that the planes had just radioed another report. The firewood truck was now halfway between Pino and La Plata. Then the cars took off, roaring away over the cobblestones.

The chief looked after them, half-wistfully, half-relieved not to be a member of one of the grim well-armed parties. Ken, reading the expression on his face, knew how he felt. Then, when the chief turned to them with a smile, Ken managed to explain to him that they would return to the police station by ten thirty. The chief nodded, repeating the hour carefully. A moment later he disappeared into the ancient municipal building.

"Watching a parade is going to be quite a letdown after the excitement of the last twenty-four hours," Sandy muttered. "But at least," he added, making an effort to conceal the disappointment he felt at having been left behind, "we'll get a chance to eat." Ken didn't reply. "Don't tell me you're not occasionally interested in food too," Sandy said.

"What?" Ken had been staring off across the placid square, with its beds of tall white calla lilies, its towering shade trees, and its neat paths. "Oh, sure," he said abruptly. "I'm interested-occasionally. But right now I'm wondering why, if the hide-out is really somewhere along that road, the brains behind it would let that truck head toward it in broad daylight."

CHAPTER XI

SNARED

Sandy didn't respond immediately to Ken's remark. Finally he said, "I'm not sure I follow you. Do you mean you think the truck is not heading for the hideout-that it's heading somewhere else? Or are you suggesting that the truck has nothing to do with the case at all?"

"I don't know what I mean," Ken admitted.

Sandy stared at him in mock amazement. "For you to admit you don't know something is quite a record."

Ken grinned briefly. Then he said, "Come on. Let's go look for some breakfast."

They strolled, side by side, away from the municipal building, which stood in the center of one side of the plaza. Beyond it was a row of shops, their fronts protected by a wide roof that extended clear over the sidewalk and formed a shady arcade. The corner shop was a small restaurant, with two or three tables standing on the sidewalk. Ken raised his eyebrows questioningly and Sandy nodded. They sat down at one of the tables and ordered rolls and coffee with milk from the waiter who appeared promptly from inside the doorway.

While they waited for the food to arrive they looked out over the green flowery plaza. A massive church stood on one side of it. The other three sides were bordered by arcades, and all of them were now coming to life. Men were rolling up the heavy iron shutters that protected their open-fronted shops. Women and boys were setting up small stands of all kinds along the outer edge of the sidewalk, and laying out their wares in neat piles-oranges, red and green chili peppers, bottles of soft drinks, and foot-long lengths of green sugar cane. Ken watched a small boy buy a piece of sugar cane and begin to chew one end of it, as if it were a stick of candy. For a moment he was so fascinated by the colorful life of the square-so different from anything he and Sandy had ever seen before-that he almost forgot the reason for their presence in Rio Claro this morning.

But when their food arrived, and he had taken his first long, satisfying swallow of coffee and milk, he said abruptly, "I shouldn't have said I didn't know what I mean. I do have kind of an idea."

"And you've been keeping it to yourself?" Sandy shook his head. "That's another record."

Ken ignored the heavy humor in Sandy's voice. "Did you ever read Edgar Allan Foe's famous story called The Purloined Letter?"

Sandy choked slightly on a bite of roll. "I wish you'd warn me," he said, "when you're about to launch into a literary discussion. Sure, I've read it," he added. "It's about somebody looking for a letter, isn't it?"

"That's right. They look in every possible hiding place-under things, inside things, behind things. And all the time the letter is in plain sight, in the letter rack on the desk. The reason it isn't seen immediately is because it's too obvious."

"And the moral of this is?" Sandy prompted.

Ken grinned. "You've guessed it-there's a moral. I'm wondering if this mysterious hide-out doesn't remain safely hidden because, actually, it's not hidden at all. Maybe it's not way off in the wilds somewhere. Maybe it's right in plain sight."

Sandy touched his forehead and bowed. "Ah, master," he murmured, "how clever you are. Who but you could have guessed that the hide-out is that orange stand right over there?" Then suddenly he sobered. "I get it," he said. "That's why you kept asking about the hotel -you thought maybe that was it."

Ken nodded. "That's the kind of place I have in mind. But I guess we've got to take the chief's word for the fact that the hotel is beyond suspicion."

"And so," Sandy reminded him, "are all the other sizable buildings in town, according to the tax collector."

Suddenly a whole class of school children marched around the corner and came to a halt almost directly in front of where the boys were sitting. At the same moment, a second group appeared on the opposite side of the square, to march around it and take their places behind the first. The girls wore uniforms-ruffled white pinafores over dark dresses. The boys were in ordinary jeans and plaid shirts. But all the children looked clean and scrubbed, and they were clearly excited. The teachers who accompanied them kept up a running murmur of low-voiced requests for silence and good behavior.

"The Rio Claro annual Red Cross parade is beginning to form," Sandy said, grinning at the children nearest him. "We've certainly got swell seats for it."

The next arrival was a sound truck, which took up its position directly in front of the municipal building and began to blast forth gay march music from the horn attached to its roof. A farm truck then pulled up behind the children, garlanded with banners that proclaimed it was the property of the Santa Luisa Agricultural Co-operative. And on a side street, just off the square, a shining new ambulance parked at the curb. The driver got out and began to polish its already gleaming fenders.

Now classes of school children were pouring into the square from all four corners. Ken and Sandy neglected their breakfast in the interest of watching each group of newcomers. Unconsciously their feet were tapping the pavement in time to the music. Ken was admiring the diligence of the ambulance driver, now briskly rubbing the glass of his windshield, when suddenly his eyes narrowed.

"Sandy," he said quietly, 'look over there. The driver of the ambulance-did you ever see him before?"

Sandy waited until he could get a good look at the man's thin, long-nosed face. "Yes, I think so," he said slowly. "Wasn't he one of the people milling around in that crowd in front of Mendoza's this morning?"

Ken kept his voice low. "I think he was," he said. "Why couldn't he have been the one who collected the fake note?"

Sandy stared at him a moment. "I don't know why he couldn't have been," he said finally, "but what makes you think he was?"

"Because," Ken whispered, "he apparently works for a hospital-and a hospital fits my specifications for a hide-out that isn't noticed because it's in plain sight. Furthermore," he added, "a hospital doesn't usually pay taxes, and wouldn't appear on a tax list at all."

Sandy whistled softly. "Master," he murmured, "maybe you really have got something this time."

"Mort Phillips is pretty sure the hide-out provides plastic surgery for its-eh-guests," Ken went on, still speaking quietly. "That means it would have to have doctors on hand, and what better-"

Sandy finished it. "What better place to conceal a purloined doctor than in a hospital? It really makes sense, Ken!"

The boy who had bought a stick of sugar cane some minutes before was suddenly standing beside their table. He was barefooted, and his jeans were faded from many washings, but the white knitted cotton shirt he wore was dazzlingly clean. And he held the half-eaten piece of sugar cane stiffly at his side as he said, "Meesters, you want guide?"

Ken and Sandy both smiled at him and his sober black-eyed face was swiftly illuminated with an answering smile. "I speak English," he assured them, and then added, "A little bit I speak. You want guide?"

"Aren't you going to be in the parade?" Ken asked him.

The boy shrugged. "Here we have many parades- for watching, for marching in. More parades we have than turistas who sometimes pay for me to guide them. But you do not have to pay much, meesters," he added quickly. "My name it is Roberto. I can show you church, school, museum, factory where is made pots of copper -anything. What you want to see?"

"Take it easy," Ken said, laughing. "How about hospitals?"

"Hospitals?" Roberto looked at Ken as if he weren't sure he had understood him. "Where the sick people go?"

"That's right." Ken nodded.

"Ken," Sandy said swiftly, "hadn't we better wait until Mort and-"

Ken shook his head. "Don't worry. I'm not getting into anything. It won't hurt to make a preliminary survey. Is there a hospital right here in Rio Claro?" he asked, turning back to Roberto, who was watching them both with his bright inquisitive eyes.

"In Rio Claro are two hospitals," Roberto told him. "Me, I do not like hospitals, but-" He shrugged, as if long accustomed to the strange behavior of foreigners. "One is here," he explained, pointing to the municipal palace. "In back of palacto is hospital of the city."

Sandy glanced at Ken. "A city hospital is a little too obvious, don't you think?"

Ken was already asking Roberto, "And the other?"

"At edge of Rio Claro-over there." Roberto gestured toward the southern outskirts of the town. "Me, I was in that hospital once," he added proudly.

"You were?" Ken was surprised. "And is it a good hospital, Roberto?"

"Very good," Roberto assured them. "My mother took me there because they have a special place where they allow to come the children. It costs nothing, this children's place. Is-how you call it?-clinico."

"Clinic," Ken told him. He could feel Sandy's glance on him again. A children's clinic was not, he realized, the sort of place he was looking for.

"But never do I see the other part of this hospital," Roberto went on. "The part for rich people."

"Oh!" Ken leaned forward but he kept his voice casual. "So there's a special place for rich people there?"

"Oh, yes." Roberto nodded vigorously. "One time I see the patio where the rich people sit when they are not so sick any more. It has many flowers. And big chairs and tables-tables with-" He gestured largely above his head with the piece of sugar cane.

"Umbrellas," Sandy supplied. "To keep the sun off."

"Si." Roberto nodded, and then he repeated the word over several times to fix it in his memory. "Um-brell-a. Um-brell-a." He grinned proudly. "Muchas gracias. This is how I learn the English."

Suddenly his eye lighted on the ambulance, parked some distance away. "Ah!" he said. "There is the- the-"

"Ambulance."

"Si." He nodded at Ken. "The ambulance of this hospital. Perhaps you wish to speak with the man who drives this-this ambulance? He can maybe tell you about the part of the hospital where the rich people go."

"No, no," Ken said quickly. "We don't want to bother anybody. We just like to look at hospitals-they interest us very much. We have many good friends in the United States who are doctors," he added, hoping that this would sound to Roberto like a reasonable excuse for curiosity. "Would you like to come with us in our car, Roberto, and show us where this hospital is? We don't want to go inside. We just want to drive past."

Roberto was grinning. "I like very much to come in your car. But, meester, if you only drive past hospital you not see anything. Hospital is behind big wall- very high. Four metres high."

"Hmm. That is a high wall-more than twelve feet," Ken murmured.

"But there is hill near the hospital," Roberto said quickly. "From top of hill I think you see hospital very good." He repeated the last phrase with a puzzled expression. "Very good? No-very well, I think. 'Very well' is better, no?"

" 'Very well' is perfect, Roberto," Sandy told him.

Ken was already moving to the door of the restaurant to pay for their breakfast. Roberto's description of the high-walled hospital excited him more than he wanted the boy to guess. He glanced once more at the ambulance driver, still busily polishing his handsome white vehicle, and then he gestured to Sandy and Roberto and they all walked back along the sidewalk to get the convertible out of the municipal patio.

If Roberto was curious about their sightseeing choice, he no longer showed any signs of it. He was too pleased to be riding in the bright red car to think of anything else. As Ken maneuvered it carefully through the crowded street, Roberto poked his head through the window and grinned happily at his friends. He didn't settle back in his seat until they had left the square and were moving along the narrow cobblestoned street into which Ken turned at the boy's suggestion. Then Roberto applied himself soberly to the job of guiding them, and pointed out the cross street up ahead on which Ken was to turn left.

The cross street was even narrower, and so steep that the convertible's powerful engine growled at the effort. At the end of a few hundred feet Ken could look back through the rear-view mirror and see the roofs of the buildings surrounding the square.

At Roberto's direction they turned right after a few blocks, along another cobbled street. This one was cut into the flank of the hill. They passed three more streets, each steeply slanted downward. Roberto pointed his finger along the last.

"See?" he said. "There is the rich man's hospital."

Several hundred feet below them they could see the huge whitewashed wall that surrounded an area equal to a city block. On the side closest to them the wall seemed built into the hill itself, and inside the enclosed grounds, among towering trees, showed the red-tiled roofs of four buildings.

Ken swallowed his disappointment. The treetops and the red roofs told him nothing. "We can't see much from here."

"But this is not the place yet," Roberto told him. "We go more far-straight ahead to next corner and then turn." He pointed to the left, up the hill.

When the convertible rounded the next corner, and nosed upward again, it was riding on a rough dirt track. Now the houses of Rio Claro were all behind and below them. There were not even any burros in sight on this rocky empty hillside. The trail ended suddenly, after a sharp curve to the right, in a small flat spot. A clump of scrubby pine trees screened the tiny platformlike place on the downhill side.

"To see the hospital very good-no, very well-we must now walk," Roberto told them.

Ken parked the car alongside the trees and took the binoculars out of the glove compartment. Then they all got out of the car and started on up the hill to another platformlike spot from which they could look straight downward, past the car and the clump of pines, to the hospital grounds some thousand feet below.

Close to the front wall, on the farthest side of the grounds, were three small buildings. Behind them, running almost the full width of the enclosure and dividing it into two equal parts, was the fourth and largest structure, a long, low building set with many windows.

"The big house," Roberto said, "is where the rich sick people live. Behind is their beautiful patio-the one I see one day when I am sick. I was living in the small house in the middle, near the gate. One day I was not feeling very sick and I take a little walk, but a doctor find me and make me go in my bed again, very quick. Very quickly," he corrected himself hastily.

"We're still too low to see into that patio," Ken said. "Let's walk up the hill a little farther, shall we?"

"Is very high hill," Roberto said. "Is hard to walk."

"Look, Ken," Sandy said, "Roberto's right. And besides-"

Ken knew Sandy thought he was being incautious. If, by any chance, this hospital was the hide-out Phillips and Gonzalez were seeking, it was foolhardy to investigate it on their own. But they could not possibly be in any danger, he told himself, on this empty hillside. "Come on," he said. "We'll just go up a little farther."

A few minutes later they all came to a breathless halt.

"Is hard to walk, no?" Roberto said.

"Is hard to walk, yes," Sandy agreed feelingly.

Ken already had the binoculars to his eyes. "This is better," he murmured. "Mmm-two men sitting in the patio under one of the umbrellas. Can't see their faces very clearly, in the shadow, but they certainly look healthy enough from here. They aren't wearing bathrobes, anyway, and one of them is smoking a cigar."

He handed the glasses to Sandy.

"Ken!" The big redhead had stiffened almost the moment he lifted the binoculars to his eyes. "There he is-Mr. Green Flame!"

They looked at each other for a brief startled moment as Ken took the glasses back again. "You're right!" Ken breathed.

"You're right," Sandy said. His voice sounded a little shaken.

"Meester!" Roberto was tugging at Sandy's arm. "What you see there in hospital?"

"Uh-nothing, Roberto," Sandy told him quickly. "Just a man we met once."

"A friend?" Roberto looked pleased. "You wish to go see him? You will take me? Always I wish to see again the beautiful patio."

"No, Roberto," Sandy said gently. "We're not going to see him right now. Let's get out of here," he added in an urgent aside to Ken.

"Right," Ken agreed briefly. As they all started down the hill again, moving as rapidly as safety allowed on the steep slope, he said quietly to Sandy, "There was a doctor too-man in a white coat who came out of the big building and spoke to Green Flame. We'd better get right back to the municipal building and try to get word through to Phillips and Gonzalez."

"We can't get there too soon for me," Sandy assured him.

They skidded down the last few feet onto the level area where the car was parked, a vivid spot of color in front of the sober pines.

Roberto was grinning. "Now we ride again. Is easier, no?"

"Is easier, yes," Ken agreed.

"Oh, much easier!" The harsh, amused voice that spoke the words paralyzed them all into instant immobility. A man was standing between the car and the trees, leaning toward them over the convertible's hood.

"Oh, sure-a lot easier." The second voice, like an echo of the first, came from the second man whom they saw an instant later. He, too, was leaning forward over the car, resting his arms on the trunk at the rear.

And both men held guns-sturdy workmanlike automatics that were pointed steadily at the motionless trio.

CHAPTER XII

BLACKOUT

Even when ken opened his mouth, after what seemed like an interminable silence, he was not sure his vocal chords would respond. Both the men facing him had the hard, muscular bodies and the hard, cold eyes of professional thugs. But it was not so much panic at the sight of them and their guns that made his throat feel tight. It was the numbing realization that he was responsible for landing Sandy and young Roberto in this predicament.

The words he spoke were steadier than he had dared to hope they would be. They even managed to sound almost casual, as if surprise were his chief emotion. "What's this all about?" Ken asked. He put an arm about Roberto and thrust the boy slightly behind his own body and Sandy's big bulk.

"Leave the boy out where we can watch him," the man at the front of the car snapped. "And start toward your car, all three of you. You first." He nodded at Sandy.

"I don't get it, do you?" Sandy glanced at Ken. He, too, was doing an admirable job of sounding merely puzzled and surprised. Nothing in his expression told Ken that he blamed his friend for this unexpected and obviously dangerous development. "Do you think they've mistaken us for somebody else-or what?"

"You'll have plenty of time for questions later." It was again the first man who spoke, and before Ken had a chance to answer. "Joe!" He addressed his companion in an unmistakable tone of command. "Go around in back of them and bring them down here. And make it fast. Those planes might decide to snoop around here some more, and this red car sticks out like a sore thumb."

"Sure, Al." The second man moved around the rear of the car and came toward them.

"Meester!" Roberto's small voice sounded at Ken's elbow. "These men are your friends?"

"No, Roberto," Ken said quietly. "We don't know them." He raised his voice slightly and spoke directly to the man named Al. "Whatever you've got in mind," he said, "you surely can't want to involve this youngster in it. He’s-“

"Shut up! I told you to save the gab until later. Hurry it up, Joe!"

Joe had stepped behind them now. He prodded Sandy's back with the gun, and with his free hand he gave Ken a shove. Instinctively Ken put his arm around Roberto again, and they all moved forward in a line. Out of the corner of his eye Ken saw Sandy's big fist close around Roberto's small brown hand, still clutching the end of the length of sugar cane.

Ken clenched his jaws tightly. He and Sandy had been in tough spots before, though he suspected they had never been in a tougher one than this. It was only too clear now that their suspicions of the hospital were accurate, and that their journey to the hill had exposed them to the men who used that building for their own illegitimate purposes. For himself-and for Sandy too, he knew-the knowledge that they had discovered the hide-out gave a quality of triumph even to their present danger. But Roberto was an innocent bystander. And yet, Ken told himself, it would be useless to shout at the boy to run for safety. These men meant business, and there would be no cover for a small boy dashing headlong down the barren hillside that fell away below them. No, there was nothing he could do right now to save Roberto.

"But we'll manage it somehow," Ken promised himself under his breath. "We've got to!"

When they reached the car, Roberto asked, his voice smaller than ever, "Now we go back to the plaza?"

"Now you go where we take you!" Joe's eyes, curiously lifted at the outer corners, glinted with amusement as he raised his free hand to cuff the youngster. But Sandy swiftly interposed an arm to forestall the blow, and Al said, "Cut it out, Joe! We've got no time to play around." To the others he said, "Get in-all of you, before you get hurt." He jerked open the car door and motioned them into the rear seat, where Roberto squeezed himself between the two boys. "You drive, Joe," Al added. He himself took the other front seat, sitting at a right angle to the back so that he could keep his gun trained on his captives.

Ken instinctively winced when Joe raced the motor violently. A moment later the car was slithering down the hill. As it bounced onto the first stretch of cobblestone, Al ordered the three on the back seat to duck their heads. "Lower!" he snapped. "I want you out of sight!”

As the car swung around a corner the cathedral clock boomed out the hour of nine, and the boys could catch snatches of brassy music from the square. Suddenly Joe braked to a halt, tapped the horn button several times, and then, a moment later, moved the car forward once more. But this time he stopped within a few hundred yards and cut the motor. Ken guessed that they had entered the main gate in the hospital wall.

Al opened the door. "All right. Get out of there now."

One glance was enough to tell Ken that they were in the patio which they had looked down on a few minutes earlier. Directly behind them a pair of doors in the long building stood wide open, permitting them to look through the driveway-like corridor that cut through the structure and on out to the far side, through another pair of open doors. The car had driven through that passage, Ken realized. But even as Ken looked, a white-coated attendant shut the far pair of doors and closed off his brief view of the front part of the enclosure, the part occupied by the three smaller structures devoted to the children's clinic.

"O.K. Let's move." Al was again emphasizing his order with his gun. "Straight ahead." He motioned them toward a small glass door set some distance farther along in the wall of the long building.

Ken glanced quickly toward the rear of the patio before he obeyed. The whitewashed stone wall was, as he had realized from above, almost a part of the hill that rose so steeply behind it. Purple garlands of bougainvillaea draped its full length, except at one point near the center where garage-sized doors stood half-open, swung inward into what appeared to be an underground garage cut into the hill itself. But he had no chance to see anything inside that shadowy interior before Al herded him along with the others.

Ken blinked his eyes to accustom them to the cool dimness of the building. He felt the smoothly polished tile floor beneath his feet, and then became aware of the comfortable furniture that lined the walls of the broad corridor they were following. He sniffed. The air was fragrant with flowers and with the scent of a rich cigar. It occurred to him, briefly, that he had never before been in a building that smelled less like a hospital. The fresh antiseptic odor that usually characterized such places was noticeably absent.

"To the left-through that door," Al ordered.

Joe moved ahead to open the door and watch their progress through it. The room they entered was large and luxuriously furnished. Deep leather chairs stood in front of the fireplace at one corner, and part of the gleaming floor was occupied by a billiard table and several bridge tables. Bookshelves and a rack overflowing with magazines lined one wall.

"Stand there." Al's gun indicated an open space before a leather-topped desk. Then he stood close to Sandy, and Joe ranged himself alongside of Ken. Roberto stood between the two boys, not quite so frightened now as he had been. His bright eyes were darting around the handsome room, eagerly absorbing sights which were strange to him.

Through a door beyond the desk three men entered the room, all dressed in slacks and gaily colored sport shirts. Behind them came the white-coated doctor Ken and Sandy had seen from the hill. His stethoscope dangled from his pocket, and he carried a small medical bag in one hand. The man who followed him was apparently an attendant. He, too, wore a white coat, but was only a short jacket, in contrast to the doctor's longer garment, and the jacket's short sleeves revealed powerful tanned arms.

Ken sensed the first three men ranging themselves behind himself and Sandy. The two men in white stood to his left, beyond Joe. No one spoke. And the faces Ken had glimpsed, as the men entered, all seemed curiously expressionless. The room had a quiet waiting quality that was more ominous than the loud crack of a gun.

Then another man came in, looked briefly at the boys, and seated himself at the desk facing them. He was short and plump, with round blue eyes in a round pink face. His neat dark business suit and dark tie, his gleaming white shirt, and almost silvery white hair all gave him the blandly important air of a bank director or an industrial executive. His voice, when he spoke, was also bland but somehow suggestive of limitless power.

"Now suppose you tell us," he said quietly, "why you were up on that hill spying on this hospital."

For a moment Ken thought that, after all, he might have been mistaken. The man sounded as if he sincerely wanted an answer to his question-as if he might merely be the director of a private hospital desirous of providing complete privacy for his patients.

"We'd like to ask a question too," Ken said. His voice was also quiet and reasonable. "We'd like to know why we were brought down here by force. If that hill belongs to you, and we were trespassing, we apologize. But I don't see why-"

"Oh, come now." The smile showed a mild impatience. "If you really want to carry on this nonsense- this pretense that you don't know what I'm talking about-that's your privilege, of course. But you might as well know that we're aware of all your activities."

"What activities?" Sandy's voice was a harsh croak. "We're tourists. And we-"

"George! Come in here, please." The white-haired man interrupted Sandy as if he were unaware of him. The quiet command was spoken over his shoulder, toward the door.

The person who entered the room, in response to his order, was the tall, thin man whom the boys had first seen at the Laredo customs station-the man whose lighter gave a green flame.

The man behind the desk asked him a brief question.

"You're certain of your identification, George?"

For the first time since he had spoken to them over the lunch table in Monterrey, the boys heard George's voice. It was easy and decisive. He even smiled at them slightly as he spoke.

"Absolutely certain," he said. "There's no difficulty about that." He pulled a cigarette out of his pocket and lighted it. The flame of his lighter was now a clear bright yellow, and when he flicked it out he grinned mockingly at the boys.

"Good." The white-haired man turned toward the boys again. "Now tell us where that other young man is-the one who was riding with you in your car."

"Right now he's probably looking for us," Ken said, wishing desperately that this were true. "We have an appointment to meet him at-"

George interrupted him. He was still grinning. "He wouldn't be dashing around the hills some place with two cars full of cops, would he?"

"You see, boys," the white-haired man said mildly, "we're trying to make it easy for you. We want you to know just where you stand-just how foolish it is to try to match wits with us. Frankly, I'm sorry to see fine young men like yourselves mixed up with the police and their stupid little plans. But you can hardly blame me for the fact that you let yourselves get involved in this situation-now can you?" He smiled.

Ken knew he couldn't speak. Hot boiling rage choked his throat and his chest. This calm gentle-voiced little man, surrounded by his gunmen, seemed to Ken the most evil and dangerous criminal he had ever encountered. The gentleness didn't detract from the danger that emanated from him. It emphasized it, made it seem even more deadly.

"And what a pity," the man was continuing softly, "that you allowed that innocent child to accompany you on your ridiculous spying mission."

"He doesn't know anything about us-or about you either!" The words burst from Ken's tight throat.

"Oh, is he so innocent?" The man leaned forward suddenly and studied Roberto's face. Ken could feel the child shrink against him. "Ah, I thought I recognized him. Yes, you were a patient here once, weren't you, my boy? And this is how you repay our generous care of you! Tut-tut." He shook his head sorrowfully.

"He didn't do anything! We told you!" Sandy half shouted. "We just hired him as a guide and-"

"And he guided you to us. Yes, that's what I mean. Ungrateful, stupid boy." Again the white head shook. Then he became more brisk. "Now, if you would care to tell us something about your friends' plans"-the blue eyes glanced from Sandy to Ken and back again- "we may be able to make your stay here a little more comfortable than otherwise."

He waited. "No? Well, it doesn't really matter, of course. There's very little we don't already know. They've gone tearing out into the hills on the trail of an honest woodman whose truck happened to break down in front of Mendoza's house this morning. They will question him until they are convinced he knows nothing-as indeed he doesn't." Once more he smiled. "He knows only that he received ten pesos for permitting his truck to break down right there. He doesn't know why. And the man who paid him is now hundreds of miles away. When your friends are finally satisfied of this they will return to Rio Claro and attempt to think of a new way to outwit me. But they will fail again. Yes, they will always fail."

The gentle voice died away and in the silence they could all hear the drone of a plane. For a moment it seemed to be almost directly over the hospital, and then the noise faded slowly away.

One of the men behind Ken cleared his throat nervously. "Maybe we ought to hurry this up, chief."

"No, no-there's no rush." The voice was still placid. "Everybody in Rio Claro knows about this hospital, and nobody has ever had reason to investigate us. What reason could they suddenly have today? The car is safely out of sight, I presume?"

"Yes, chief." It was Al who answered him. "Underground."

"Excellent. Then we have nothing to fear." He looked for a long moment at Ken and then for an equal time at Sandy. "Too bad, too bad," he murmured. "You do look like nice young men. But you know the old saying-that a person is known by the company he keeps. And I'm afraid you've been in very bad company indeed."

Ken began to speak, hardly aware of what he was going to say, but only knowing that he had to make some effort to break through the smothering sense of danger that seemed to fill the room like an impenetrable fog. "I don't know what you intend to do with us," he said, "but if the man who's been riding in our car is a policeman, as you say, you might be interested to know that we're expected to meet him this morning. And if we don't turn up for the appointment, he'll start a pretty thorough investigation of this town. Even your hospital won't be left out of it." He knew the words sounded feeble even as he said them.

Obviously the white-haired man recognized their feebleness too. "Are you trying to tell me something?" he asked politely. "Did you want to tell me what time you are expected to meet him?"

Ken had learned his lesson. Nothing he could say right now would do them any good.

"Let me ask him, chief." George moved slightly in Ken's direction. "He'll answer me."

"I'd like to remind you, George, that if you hadn't blundered at Laredo yesterday we wouldn't have these young men on our hands now." The white-haired man's voice was still gentle, but it was obvious that George, too, feared the power behind it. He fell back to his previous position. "That's better." The older man rewarded him with a faint smile.

Then he turned again to the boys. "Let's introduce ourselves, shall we, before we get on with our business? I'm Dr. Gosset, head of this hospital-as you have already surmised, no doubt. And you are?"

This time in the silence there was no throb of a plane overhead.

"Oh, come now," Gosset said, "you mustn't deliberately try my patience. I can easily have you searched for identification."

"I'm Ken Holt," Ken said grimly. "And that's Sandy Allen."

"I am Roberto Rosario," Roberto said. "And I do not like it here. I want to go to my house." Roberto's curiosity was no longer strong enough to hold his fear at bay. His voice trembled.

Ken took the boy's hand. "Take it easy, Roberto," he said quietly. "We'll go home-soon."

"I just remembered something, chief!" Joe leaned forward urgently. "That name Holt-I'm sure I read it yesterday in the English page of that Mexico City newspaper."

"So?" Cosset looked at him expectantly. "What did you read about it?"

"I can't quite- There's the paper, chief. I'll check." Joe reached for the folded sheets of newspaper on the nearest table. "Sure!" he said an instant later. "Here it is-a story about some big conference, signed by a Richard Holt."

"Richard Holt?" The blue eyes fixed themselves on Ken. "Any relation of yours?"

"My father," Ken told him shortly.

Joe groaned. "Let's get rid of these kids, chief. You know how newspapermen are. If they get their teeth into some-"

"Let me worry about that, Joe," Cosset broke in.

"But if anything happens to Holt's kid, chief, he'll have the whole Mexican army called out before he drops the business."

"The Mexican army-or any other army-is no smarter than a police force. And no police force has alarmed us for years."

Cosset's last words were almost drowned out by the zooming sound of a low-flying plane. But he only smiled faintly at the noise. "You see," he said calmly, "that's probably an army plane, hunting blindly over the countryside like a bat in a cave. And no more danger to us than a bat would be." He looked at the boys with what appeared to be untroubled curiosity. "Do you think it's looking for you, perhaps?"

Ken glanced automatically down at his watch. It was barely nine thirty. Nobody would be even faintly concerned about Sandy and himself until they failed to return to the police station a full hour from now. Ken looked away from the questioning blue eyes, hoping that his silence would be taken as an attempt to conceal knowledge of the plane's activity.

"If so, of course," Gosset said, "it's too bad to disappoint them. It won't be for long, however. Tomorrow we shall even help them to find you, if they cannot do so themselves. But to have them drop in today would be extremely inconvenient. I must admit I'm pleased that there's very little chance of that."

Ken listened to the rambling words with half a mind. Dimly he realized that Gosset's offer to "help" a plane find them the next day was more a threat than a promise. He felt sure now that Gosset never intended Sandy and himself-or Roberto either-to be found anywhere, alive. But Gosset's words disturbed him less than the fact that the white-coated doctor and his attendant had moved behind him, out of sight. He heard, faintly, the sound of liquid being poured. Almost immediately he became aware of a new sweetish odor in the room-an odor he had smelled in hospitals before, but which had been noticeably absent from this place. Despite Joe's armed presence beside him, he half turned.

His own motion coincided with the swift motion of the doctor and his assistant as they stepped to either side of Sandy and pinioned the redhead's arms.

In almost the same instant Ken's own arms were grabbed from behind and pulled back in a vicious grip. A wet cloth whipped past his ear and clamped itself against his face.

In a split second the sweetish odor identified itself. The word chloroform seemed to rise up before his closed eyes in towering letters.

With all his strength Ken twisted his head toward the right. For three ticks of a clock he wrenched his face entirely clear of the choking cloth. Frantically he gulped air into his lungs before the damp weight pressed down again over his nose and his mouth.

For as long as he could he held his breath. The time seemed endless. Even the pain of the viselike grip on his arms became insignificant in comparison to the agony of his thudding temples.

And then, finally, he gave way. Helplessly he sucked in air through the smothering mask.

He tried to struggle then to loosen his arms, as the sickening smell of the anesthetic rolled up inside his head. But it was no use. He felt the strength drain out of his muscles, felt a heavy weariness engulf him. And then it was over. He sank into blackness and silence.

CHAPTER XIII

BARRICADE

It seemed to Ken that he was struggling desperately to climb out of a deep well, to claw his way to light and air somewhere far above him. His chest heaved and his fingers scrabbled over cold stone. But the stones were smooth and tightly fitted together. He could find no fingerholds. His hands went limp and for a moment he was quiet, panting with exhaustion.

Then, quite suddenly, he remembered everything that had happened. He recalled the violent moment when Sandy was attacked, and when, almost simultaneously, the chloroform mask had been clamped over his own face. He remembered his final frenzied effort to gulp air into his lungs, before the blackness came down over him.

His last moment of consciousness had been spent, he knew, in the Rio Claro hospital which no one-except Sandy and himself-recognized as the hide-out Phillips and Gonzalez had long been seeking. But where was he now? Where was Sandy? Where was the small frightened boy named Roberto? Had he himself been unconscious for days, for hours, or only for minutes?

But though the questions moved through Ken's brain, they did not seem to require answers. The effort of remembering had left him too spent to feel worry or even curiosity. The scene he had just recalled could no longer alarm him. It seemed to have happened long ago, to somebody else.

Slowly, aimlessly, he moved his heavy arms. Again his hands slid over smooth stone. But now he smiled to think he had believed himself pressed against the wall of a well. He realized now that he was lying on his face on a stone floor. The stone was cool against his cheek and there was dank, dead air in his nostrils.

"If I turned over on my back," he thought vaguely, "I could see where I am." But was it worth the effort?

He lay there a while longer, breathing laboriously. The dank odor of the stone grew unpleasant. He decided, finally, that he would turn over, to get away from the stone.

It was an even greater task than he had thought it would be. His muscles were soft putty, completely without strength. His body was lead, heavy and inert. But he forced himself, stubbornly, to accomplish the feat.

He was panting again when he finished, and his palms were wet. But it was good not to have the stench of the stone close under his face.

He opened his eyes after a minute, and then closed them and opened them again. It made no difference. There was only blackness. Was it because he himself could not see, or because the place where he lay was darker than the darkest night? Perhaps, he thought dimly, he was locked in an underground vault. And yet he had a vague sense of open space above him, and on either side. It occurred to him that he could sit up, perhaps even stand up.

He reminded himself that he had been able to turn over simply because he willed himself to do it. If he willed himself to sit up, he might achieve that too.

He slid his hands along the stone, to plant them firmly, still wondering why he should drive himself to such a difficult task. Suddenly his right hand touched something solid and faintly warm. As he closed his fingers around the unexpected obstacle, the nerve ends in his fingers flashed a message to his still only half-conscious brain. He was clutching Sandy's shoulder.

In a single instant, then, Ken came to himself. "Sandy!" Ken thrust himself up without even being aware of the effort. "Sandy!" He grabbed the shoulder again and shook it. It moved limply under his hand.

Now Ken's brain churned wildly. Was Sandy dead or merely unconscious? If only he had a light he could find out. If only-

Suddenly he stopped shaking Sandy, stopped gasping his name. Faintly, somewhere near at hand, Ken had heard voices. He opened his mouth to shout for help, but some warning instinct kept him quiet.

The voices grew louder. A chain rattled, wood scraped on stone. And a thin vertical slit of light cut the gloom. Some twenty feet away from Ken a pair of tall doors was being pushed slightly inward, to admit a long streak of brilliant sunshine.

Crouching there beside Sandy, blinking his eyes at the unexpected brightness, Ken became aware of how weak he was. If Gosset or any of his men were about to enter this stone-floored prison, he would be unable to put up any fight at all, either for Sandy's sake or his own. Without being aware of planning his strategy he did the only thing that occurred to him. He lay down on the cold stone again, face to the floor, in the same position he had been in when he first began to regain consciousness. He shut his eyes, as the door opening widened. For a split second, before his lids closed against the increasing light, he saw a familiar-looking car wheel not half a dozen feet away from his head.

Again there was the ragged sound of timber scraping over stone, and then the noise of at least two pairs of footsteps on the rough floor. Ken could sense figures coming near him.

"Still out cold." The unidentifiable voice spoke almost directly over his head and a glare of light struck the lids of his eyes. Ken forced himself to lie limp and flat and still.

"Well, what did you expect after only about forty-five minutes? Doc said it would last a couple of hours probably." The answering voice sounded like Al's.

"But he said you never could be sure." Ken recognized now that this was the man called Joe.

"Well," Al said, "in any case we don't have to wait around in this hole." One pair of footsteps moved away a little.

"Wait a minute, Al. I want to tell you something. I don't like this setup one bit. Monkeying around with the son of a newspaperman like that Holt fellow-you can see he's important if they put his name in the paper- is just crazy. Leaving them here all day is even crazier."

"Relax, Joe," Al said impatiently. "Have you ever known the chief to slip up? Besides, what else could we do after we saw them snooping around? We can't arrange a good legitimate-looking accident in broad daylight, can we? You know what a mess Mendoza made of that one he tried to pull, don't you? What would you suggest, anyway?"

"Clearing right out-that's what," Joe said belligerently. "And that's what the chief would do if he didn't care a lot more for his investment than he does for out necks. Just because he's got a lot of money sunk in the hospital-"

"You'd better not let him hear you talking like that, Joe. Old Doc Gosset may be crazy as a loon in some ways, but he's managed this business pretty smartly so far. If I were you, I'd keep my mouth shut-unless, of course, you want to clear out yourself?"

Joe's short laugh was low and ugly. "Never mind. I know what happens to people who try that." Then his voice raised in an angry whine. "But can't we at least tie these kids up, so we don't have to play nursemaid to them all day?"

"And leave marks on them that even the dumbest policeman would notice when their bodies are dragged out from under a car? Use your head, Joe!" Al snapped. "Anyway, I told you, we don't have to stay inside here. The walls are three feet thick, there are no windows-and those doors would stop a truck. Even if the kids do come to, and yell their heads off or start trying to beat their way out, there's nothing they can do. Come on." Footsteps retreated firmly.

"O.K. But I still think it's a mistake. The whole thing's a mistake." Joe's feet lagged as they moved farther away from Ken, and the sound of the doors being pulled shut again cut off his last resentful mutter.

Ken lay perfectly still for one moment longer, trying to stop the shivers that had been running through his body ever since he fully realized what lay ahead for himself and Sandy, and presumably for Roberto too. He told himself that he'd had a stroke of luck because now, at least, he had knowledge with which to plan ahead.

But he had no time to waste. It was impossible to guess how soon Al and Joe would return to check up on them again.

Grimly Ken pushed his hands against the cold floor to bring himself up to his knees. Roberto was somewhere in this same enclosure, he supposed, but the first thing to do was to see if he could rouse Sandy. Then together they could try to work out some scheme to rescue themselves.

"Sandy, Sandy," Ken whispered, shaking the redhead's shoulder once more. "Sandy-wake up!"

The big body remained inert beneath his hands. Ken slapped Sandy's cheeks then, lightly at first but with growing fierceness. "Sandy! Can't you hear me? Wake up!" Sandy's head rolled back and forth beneath the blows, but his slow, regular breathing was uninterrupted.

It was no use, Ken knew.

He swung around then and began to crawl over the stone floor in the dark. If he could find Roberto, that would be some small gain. Just to know that the small boy was still alive would be a relief. Roberto was so young-it was hard to know what reaction he might have had to a dose of chloroform similar to the one that had Sandy still unconscious. Ken knew that his own last-minute gulp of air was all that had prevented him from receiving an equal amount.

After five long frantic minutes he found the boy's body. Roberto was alive-yes. But, like Sandy, he failed to respond to shakings and slappings. Ken sank back on his heels finally, almost overcome with weakness and hopelessness.

What could he do by himself against two armed men?

Then, suddenly, he remembered the car wheel he had seen in the brief moment of light before he had closed his eyes when Al and Joe entered. It was the wheel of their own convertible-he felt sure of that- and the car must be parked just inside the big doors, hood pointed toward them. A way to utilize it leaped, full-formed, into his mind.

He'd get in the car, behind the wheel. And the instant he heard the doors opening he'd drive the car against them-rip them from their hinges and escape into the open. He was certain now that their prison was the underground garage, built into the hill behind the patio. If he drove fast enough, straight along the passage cut through the long building, he would reach the outer, public section of the hospital before anyone could stop him. And there, surely, he could call for help. He only had to find the car, climb into it, get the ignition key turned on and ready.

He had completely lost track of where he was, in relation to Sandy and to the wheel he had seen long minutes before. Again he crawled around in the dark, feeling ahead of him with his hands, for what seemed like hours. But finally his fingers found the smooth patterned curve of a wheel and Ken gasped his relief. Clutching its upper edge, and then the fender, and finally the door handle, he pulled himself erect. He turned the handle, clinging to the door as it opened out against him. Then he edged around the end of it and flung himself forward over the front seat, his right hand fumbling for the switch.

He should be close to it now. He knew every inch of the dashboard by heart. There-he had found it!

The key was missing.

For a moment he refused to believe it, and his hand slid back and forth over the smooth dashboard. He told himself that he had, after all, made a mistake.

But it wasn't a mistake. The feel of the switch under his fingers was unmistakable. And the key that should have protruded from the narrow slit was not there.

His hand dropped to the floor and he wasted another minute exploring the ridged rubber mat, in the frenzied hope that the key had dropped out of place. Finally he gave up.

He lay slumped face downward on the leather seat for a long time, unable to think of another plan of action, unable to summon the strength or the hope to urge himself to further movement.

His throat felt dry and parched. His body was shivering again. If only Sandy were awake! Sandy understood all the intricacies of motors. He could start an engine without a key, if necessary.

And then another numbing thought flashed through Ken's mind, and he knew his inspired plan wouldn't work even if Sandy could be aroused to help him. The big doors he had watched move open, grating noisily on the stone floor, swung inward. Even if he could drive the car against them, he could achieve nothing more than pushing them shut.

He remembered the quick glimpse he had had, before Al and Joe herded Sandy and Roberto and himself into the long building, of the garage doors set into the flower-draped wall. They were heavy doors, and they were braced by a heavy timber threshold. It would, in any case, be impossible to catapult them open, knocking down the men who stood just outside, and make a dash through the patio and the passageway to the front of the hospital.

It was no use. They were caught here, helpless- trapped in a prison from which there was no escape. And outside Joe and Al waited to-

Ken's thoughts came to an abrupt halt. That was the important point, he suddenly realized: Al and Toe were outside! If he could manage to keep them tnere, he and Sandy and Roberto would be safe at least temporarily.

All he had to do was to transform their prison into a fortress. It was as simple as that. And the doors were the only thing he had to guard. Al had said there was no other way in or out of the place.

Ken began to move automatically, doing the things he knew had to be done. His hand found the emergency brake and he turned the handle, releasing the catch and easing the brake off.

If only there was time enough! Somehow, he had to get the car so close to the doors that its bumper touched die wood. Then it would provide a barricade against the doors' opening. Even as he felt his way toward the rear of the convertible he raged at himself for not thinking of this idea sooner, for wasting priceless minutes in despair.

Ken placed himself in the middle of the rear bumper, back to the car, and bent his knees until he could grasp the bumper in his hands. Then he put all his weight against it. Almost immediately it began to move.

His strength was returning to his muscles. Even as he pushed he felt stronger and more powerful. But when the car had rolled a few scant inches it stopped, bumping softly against some unevenness of the stone floor.

Ken let the car roll back again, waited a moment to catch his breath, and then heaved once more.

Again the convertible rolled forward, struck the uneven stone, and stopped. Ken dug his heels against the floor, fighting for a grip. Under his desperate thrust the car lifted, fell, and then moved forward again. It moved six inches-nine inches-a foot.

Ken's chest was heaving. How far away from the doors had it stood when he started this stupendous task? He wasn't sure. And he couldn't waste time now by measuring the distance he still had to push it. He thrust backward again, and again the car rolled gently a few more inches.

Suddenly above the pounding in his ears Ken could hear voices. Al and Joe were coming back! Somehow, from somewhere, Ken found new strength. He was only barely aware of the sharp edge of the bumper cutting into the palms of his hands. He drove his heels against the floor until his leg muscles were as stiff as steel bands.

The chain on the doors rattled. But the car was still moving-another half foot, and another and another. That ominous sound of wood scraping over stone-the sound that meant the doors were beginning to open- had just reached his ears when he felt the car nudge gently against an obstacle. He had made it! The convertible's front bumper held the doors shut against an angry thrust from outside.

"Push hard! They always stick a little." Al's voice, heard dimly through the wooden barrier, was sharper than it had been before.

"They're not stuck! Something's shoved up against them!"

"Here! Let me see!"

Ken held himself rigid, every muscle straining to keep the car in its position against the push from without.

"You're right! There is something holding them!" Al sounded more surprised than angry.

"I told you!" Joe wailed. "They came to-like I was afraid they would-and they've got themselves barricaded up in there. Now what are we going to do?" His voice suddenly rose. "All right!" He was no longer speaking to Al, Ken knew. He was directing his words through the doors. "Get away from that door or I’ll shoot."

"Put that gun away, you fool!" Al said fiercely. "How much good could you do shooting through that door? Besides, don't you remember-they're not supposed to be marked? Here, let's shove together. Now!"

Ken felt his feet slide on the stone as the car was pushed against him, away from the doors. His heels slid into a wide crack between two of the stones and he drove against the tiny hold with all his might. Once more he felt the car roll toward the doors. Softly they thudded shut.

The next shove was sudden and strong. For an instant Ken was almost caught off balance. But miraculously his heels slid into the groove again and once more, with agonizing slowness, he drove the convertible's nose against the timber panels.

But he couldn't keep it up, he knew. Once more- perhaps twice more-he could summon up the strength to answer their thrust. But then the men's superior weight would triumph. The doors would open wide enough to let them slide through. And that would be the end.

If he could only get at the emergency brake to lock the wheels! If he could find something-anything-to push beneath the tires and prevent them from rolling! But he didn't dare leave his post to search for blocks. He didn't dare leave even for the few seconds he would need to hurl himself into the car and jerk up the brake. All he could do was to hang on, where he was, for as long as he could stand it. After that . . .

"Ready?"

The word penetrated the wood only faintly, but it gave Ken a flash of warning. He braced himself. Once more he and the two men outside played their deadly game of seesaw and once more Ken managed to win. But it took all the strength he had, and more. His breath was tearing at his throat.

"It's all over," he thought dimly.

He wondered vaguely what it was Al and Joe were saying. He couldn't make it out. That murmuring sound was unlike their angry voices. It was fainter and-and nearer! It was inside the prison, not far from where he stood.

"Sandy!" Ken gasped. "Sandy!"

A shoe scraped on stone. "Ken? Ken, where are you? It's dark. I can't see anything." Sandy's voice was only a husky quaver.

"Sandy!" Ken sent his own voice toward his friend like a missile, determined to penetrate the cloud out of which Sandy was emerging. "Sandy! Get up! I need you!"

"But where are you? I-" Again the shoe scraped on stone, this time with a stumbling sound.

"Over here, Sandyl Follow my voice. Here! Here!"

Outside Al said grimly, "You ready now? Give it everything this time. We almost made it before. Come on!"

But now Ken had hope again and his aching muscles had new vigor. He ground his heels into the crack and waited. And in the moment before the shove came, he found time to say "Here, Sandy! This way. Here!"

"I'm coming. If I only knew-"

The rest of Sandy's words were lost as Ken heaved against the push of the car. The car moved only a scant few inches that time before he forced it back against the doors. Immediately, still breathless, he began the chant again, "Here, Sandy. Over here."

He wasn't trying to make Sandy understand anything. He knew the effect of the chloroform was still too strong for that. But if he could just get him near enough-could just get him to do one thing- "Here, Sandy," he repeated. "Here."

The shuffling footsteps were closer now, were only a few feet away. Ken longed to reach out and pull Sandy toward him-he felt sure he could grab him in a split second-but he didn't dare.

"What's the matter with you, anyway?" Al was berating Joe furiously. "You've got about as much strength as a puppy! Now this time we'll really hit it! Ready?"

The car quivered slightly and Ken knew Sandy had blundered against it.

"Great!" he said swiftly. "That's the car you're touching, Sandy. Our car."

"It is? But what-?"

"Never mind. Get in. Pull the emergency brake. Quick! Quick, Sandy!"

"I'm ready all right!" Joe growled. "I'm ready to get my hands on those-"

"Save your breath!" Al snapped.

The faint creak was the car door opening. Sandy was moving with maddening slowness. And then the car sagged slightly on Ken's right and he knew Sandy was climbing in.

"Quick!" he said once more. "Pull the emergency brake!"

The last word was a gasp. Once more, from outside, the big wooden doors were yielding under a violent thrust. The crack of light they admitted formed a pale wall of dancing dust motes that cut through the dark space like a gauze curtain.

Ken felt the car force itself against the backs of his legs, felt himself sliding forward. He couldn't hold it. He couldn't. But he gave one last desperate heave and the curtain of light evaporated.

Instantly the pressure on his back began again. It was beyond bearing this time. It-

Then he heard it-the wonderful rasp of the emergency brake being pulled up. The thrust against his back eased. The car stood still, solid as a rock.

Ken unbent his fingers, gripped painfully around the bumper. He made his shaky legs carry him around to the driver's seat. He reached inside and gave the brake lever another yank.

"Was that what you wanted me to do, Ken?" Sandy's voice still sounded vague.

"That's what I wanted." Ken dropped his arms on the edge of the door and let his head sink forward on them. 'That was it, Sandy."

CHAPTER XIV

SPARKS OF HOPE

The car door that Ken was leaning on quivered slightly. Dimly his mind registered the fact that the men outside were again trying to force an entry. It didn't matter, he thought. There was nothing he could do about it any more. He was too tired. Too tired to raise his head, to open his eyes.

And then he realized that the car was holding. He was no longer bracing it with his back. It was holding alone.

Slowly the wave of exhaustion receded and Ken became aware of the new situation. Sandy had pulled up the brake and it was no longer necessary to beat back each attack with the strength of his own aching muscles.

"Ken?" The familiar voice was close to his ear. And though it sounded weak and faint, it was a familiar voice-not the vague murmur of one still more than half unconscious.

"Right here." Ken forced his head up, opened the door on which he had been leaning, and climbed inside the car to slump down beside his friend.

"Where are we? What happened?" Sandy's voice was stronger with every syllable. But he was still as confused as Ken had been when he first began to emerge from the anesthetic.

Ken put his hand on his friend's arm and the warm human contact somehow restored his own strength. The realization that he was no longer alone struck him with the impact of a blow.

"I remember now! They chloroformed us!" Sandy was saying. "But where are we? Where's the boy? And what was all that about brakes a while ago? I'm still dizzy-I can't seem to-"

"Take it easy," Ken said. He put into his voice all the confidence he could summon up. Sandy needed time to sort out vague impressions and separate fact from dim chloroform-induced fantasy. Ken knew only too well how difficult that was to do, especially in the utter darkness of their prison.

Suddenly Ken realized that the darkness was unnecessary. He reached forward and flicked the switch of the headlights. Immediately the great weathered gray timbers of the doors just in front of the car were brightly illuminated, and the glow reflected back into the car. Ken turned and looked at his friend. Sandy's big bulk was a comforting sight, even when the redhead was still rubbing a limp hand over a pale, sick-looking face.

"The dizziness will clear up pretty soon," Ken said firmly. "Just take it easy."

As he spoke, his eyes were traveling over the heavy doors, each formed of huge timbers apparently several inches thick, and crisscrossed with almost equally heavy braces. The walls that stretched away into dimness on either side of the doors were made of big smooth stones, like the stones of the floor.

Ken's eyes fell on a small heap of firewood not far from the car's front right wheel. He remembered how desperately, only a few minutes ago, he had wanted blocks for the convertible's wheels. Blocks would still be a valuable bulwark to the strength of the emergency brake. And these were perfect for the purpose-triangular splits from a log that must have been more than a foot in diameter.

"I'm going to put a couple of blocks under the wheels," Ken said, sliding out of the car. "I'll be right here, Sandy."

The splintery pieces of wood hurt the palms of his hands, still deeply grooved from his fierce hold of the bumper. But Ken gritted his teeth and carried them two at a time, kicking and prodding each one beneath a wheel.

There was no longer any noise outside the big doors, Ken realized. Had Al and Joe gone away long enough to bring up reinforcements? In any case, the barricade he had formed with the convertible could only provide temporary safety. They had to make plans. They had to-

"Ken? You haven't told me where we are," Sandy said.

Ken took a deep breath. Sandy sounded as if he could understand things now. "I can tell you where I think we are," he said, coming back to the car.

'This seems to be the situation." Ken spoke quietly, watching Sandy's face and speaking more quickly as he saw its expression change from blank incomprehension to at least a partial understanding and accepting of their position.

"I don't know where you found the strength," Sandy murmured once. "I couldn't push this car, now, if-"

"Sure you could," Ken assured him. "If you had to. But I certainly was glad to feel that brake go on."

When he had finished telling Sandy what little he knew himself, he said, "So let's take a look around here first and see just what kind of hole I've got us trapped in."

"You?" Sandy blinked at him.

"Sure. It's my fault we were picked up. I'm the one who insisted on taking a look at the hospital."

Sandy reached toward the glove compartment. "Cut it out," he said. "We're wasting time."

Ken didn't argue with him. He was too glad to hear the brusque note in Sandy's voice, to know that from now on they were really facing this predicament together. Sandy found the flashlight and climbed out of the car. When he first put his feet on the ground, he clung to the door handle a minute, weaving slightly. But then he raised the flashlight and flicked it on, and they both followed its beam as it traveled in a slow arc.

They were in a windowless enclosure measuring some forty feet from the double doors to the back wall, and about twice that distance in the other direction. The ceiling was of rough planking laid above untrimmed logs. Ken studied it for signs of a trap door, but found none.

"Good," he muttered. "Then nobody can get at us from there."

In one corner there was a circular stone construction which on closer inspection proved to be an ancient forge. A masonry hood, six feet above the hearth, had been designed to catch the smoke and funnel it into a stone chimney. Ken leaned over the edge of the forge and peered upward.

"I can see light," he said. "But the chimney's only about a foot square inside. I guess nobody could get through there either." He took a deep breath. "So it looks as if the doors were our only problem."

He hadn't told Sandy yet, but he felt convinced that when Al and Joe returned to the attack they would no longer be using merely their own strength. They probably would have a truck or a car of some sort, with which they would attempt to ram the doors open.

As the flashlight continued its survey of the room Ken watched for the sight of something-anything-which might serve as added weight to the barricade now formed by the convertible. The yellow beam slid over a small pile of broken bricks, several rusted five-gallon cans which had once contained oil, and a couple of splintered worm-eaten planks. Ken shook his head. None of the dusty litter was of any use.

And then he caught his breath. "Look!" he said. "A model T Ford!"

The flashlight was illuminating a fantastically battered old roadster, its four thin tires flat and cracked open from years of disuse, its top gone, its high-set body covered with a thick layer of rust. Ordinarily Sandy's mechanical interest would have leaped at the sight. But now it was Ken who was aroused.

"Can we drag it up against the back bumper of our car?" he asked. "It would add a lot of weight to our door block."

"Sure we can," Sandy told him slowly. "If you think we need it."

"We'll need it all right," Ken told him then, "if they decide to try to break the doors down by driving a car through them."

"Oh." Sandy's brow furrowed and Ken knew that his friend was just beginning to foresee the grim problem that still lay ahead of them. "All right. Come on."

Ken was still afraid to urge Sandy to hurry, for fear his slowly returning strength would be wasted in panicky motion. The car moved sluggishly on its flat tires, an inch at a time. They pulled it forward and then had to cut the front wheels over and back it up, in order to shift its direction. Finally, after several such maneuvers, the old car was close to the convertible's rear and sideways to it, its rusted left side in contact with the convertible's bumper.

"O.K." Ken was out of breath. "To skid our car backward now, they'll have to move this ton of scrap sideways."

"Hey! You in there!" The shout from outside was their first indication that Al and Joe had returned. "This is your last chance!" Al warned them harshly. "Clear the doors!"

Sandy stiffened. Ken shook his head, warning him to silence. A long moment went by.

"All right!" Al shouted then. "You're going to regret this."

They could hear a car motor roar.

Sandy turned suddenly and took several long strides to the pile of broken bricks that lay on the floor. "If they crash through there," he said, "we're going to fight."

Ken started to protest. A handful of bricks, he knew, would be small defense against the arms Al and Joe would undoubtedly bring with them if-or when-they battered the big doors open. If the barricade didn't hold, he and Sandy and the still unconscious Roberto would be lost. It was their only real hope. But Ken knew Sandy would feel better if he had some kind of weapon at hand, and so he too gathered up as many of the broken bricks as he could carry. They both returned to the doors and stationed themselves on either side of the convertible. Each had a pile of bricks at his feet, and a single sharp-angled one held tightly in his right hand.

The big doors quivered slightly. The car outside had bumped gently against them.

"All right, Joe," Al ordered tersely. "Give it all you've got."

The engine outside speeded up and the pressure against the doors increased. With infinite slowness the heavy timbers moved inward until there was a half-inch slit between the two wide panels. The convertible moved backward slightly too, as the tires tried to climb the wheel blocks. But a half inch was as far as the barricade yielded.

The roar of the engine rose another notch in volume. The slit widened another quarter of an inch. Sandy's throwing arm lifted. Ken's heart was thudding against his ribs. A sudden vision of Gonzalez's big car, with its whip antenna and its two-way radio, flashed through his mind and he wished desperately that that car stood in the red convertible's place. Then they could be flashing an appeal for help into the ether, with the certain knowledge that Phillips and Gonzalez would pick it up. If only there were some way they could get a message through the stone walls of this prison!

The convertible was rocking under the pulsating surge of power on the other side of the doors. But its brakes still held, and the wheel blocks and the old car prevented the tires from being skidded rearward.

The laboring engine outside thrust even harder for an instant. And then it stalled. The tremendous pressure against the doors eased suddenly. The convertible rolled forward and jammed the doors tightly shut.

"Whew!" Sandy wiped perspiration from his face with the back of a hand that still clutched a brick in a paralyzing grip.

"So far so good," Ken said. "But-"

Al’s angry voice snapped a command. "Back up and ram them!"

The engine started again. The car outside backed away from the doors and stopped. The noise of the motor subsided as the driver shifted to forward, and then it rose again as the car drove ahead. An instant later its front bumper was crashing against the wood. The heavy panels thudded backward against the convertible's bumper, and the red car bucked as it reared up on its blocks. Its back bumper clanged noisily against the old Ford.

But even before the noise died away, Ken could see that the impact had achieved nothing. The convertible held fast and the doors remained closed.

"Try it again!" Al ordered.

"But I'll wreck this-"

Al overrode Joe's alarmed protest. "Wreck it! But get those doors down!"

Once again the car outside could be heard backing off and then charging forward. And once again the stone walls echoed to the clang of crashing wood and metal.

But again the barricade held solidly.

"The wheel blocks!" Sandy said hoarsely, and bent swiftly down. The toe of his shoe drove hard against the log splits.

Ken glanced at the blocks on his side of the car and saw that they, too, had shifted slightly. With all his strength he jammed them back into place.

The car outside had backed away again. Its motor was idling now. Ken listened, waiting for the roar that would mean another attack. But instead he heard voices in low, angry argument.

Suddenly a fist thumped furiously on the door. "Don't think we're giving up!" Al called to them. "We'll get you out of there if we have to blast the doors in!"

A moment later the car motor picked up a little, but to the boys' amazement the sound then diminished into complete silence. The car had driven away.

"Blast!" Sandy repeated faintly. "If they blast-" He looked down at the brick in his hand. Slowly he opened his fingers and let it drop. It hit the stone floor with a dull crack, a gesture of surrender.

"They won't blast," Ken told him sharply. "They wouldn't risk making that much noise." But he knew that Sandy, like himself, was now thinking of the many other things Al and Joe could do instead, things against which he and Sandy would have no defense. Sandy looked defeated, and Ken could feel himself sinking into despair.

A small whimper reached his ears. Ken's head snapped up. "Roberto!" He ran around the car, grabbed Sandy's arm, and pulled him along to the small boy still lying on the cold, stone floor.

As they neared the little figure, Roberto tried to raise himself on one arm. He shrank back in fright as the beam of the flashlight encompassed him.

Ken swung the light aside and knelt down. "Roberto," he said quietly, "are you all right?"

Roberto looked at him with wide eyes. When he recognized Ken he relaxed slightly. "Senor," he asked weakly, "why is my head turning and turning?"

"Don't worry," Ken told him. "It'll stop turning pretty soon. Won't it, Sandy?" He looked up at the redhead, towering above them.

"Sure it will, Roberto," Sandy said, but his voice was unconvincing.

"But those men-they are here?"

Roberto's terror struck through to Sandy. Suddenly he knelt down and took the small brown hand in his own big one. "Don't worry, Roberto," he said steadily. "They're not in here, and we're not going to let them in. We're glad you woke up," he went on, "because we've got a job for you to do. Do you think you can manage it?"

Roberto lifted his head a little from Ken's supporting arm. "A job I can do, senor?" he asked hesitantly.

"Sure you can do it," Sandy told him. "Come on. I'll show you." He picked up the slight figure, winked briefly at Ken over Roberto's head, and carried the boy to the hooded forge in the corner. Seating him on the stone hearth, he said, "There. Now you keep an eye on that chimney up there and let us know if you see anything-anybody looking in through the top, or trying to drop anything down. All right?"

Roberto's lip was trembling but he bit it firmly. "All right, senor. I watch. But you are not going away?"

"No, of course not," Sandy assured him. "We've got our job to do right over here. And don't you worry-if you do your job, and we do ours, we'll keep those men outside."

"Nice going, Sandy," Ken said quietly a moment later, when they had drawn a few steps aside, in the direction of the convertible.

Sandy grinned wryly. "I learned the technique from you." The grin faded. "But what is our job, anyway? I'm sorry I panicked there a couple of minutes ago. But"-he drove a fist fiercely into a palm-"but it's being stuck in here unable to do anything."

"It's eleven o'clock already," Ken said, trying to keep his own voice steady. "Maybe the chief of police has already reported to Phillips and Gonzalez that we haven't turned up. Maybe-"

He broke off abruptly at the sound of a gentle knock on the big wooden doors.

"Holt-Allen-can you hear me?" It was the voice of Cosset.

The gentle mildness of it, filtered through the heavy timber, was more deadly than ever. Ken could feel his blood chilling in his veins.

"You don't have to answer," the voice continued. "I know you've recovered from the little nap I arranged for you. Too bad, really-I did it for your own good. I'm afraid you've been wasting your time, however, with your efforts to barricade yourselves inside there. Though I admit it was clever of you, under the circumstances. Quite clever indeed. You surprised me." He chuckled.

"Your friends, however," he went on, "have not surprised me. They have returned from their fruitless journey, just as I expected, and are beginning to wonder where you are. They have already made inquiries in the plaza, where your car was seen. But unfortunately people were more interested in the parade than in yourselves, and have not even told them the direction you took when you left the square. And of course your handsome car is now out of sight, so that the two planes circling overhead for the past twenty minutes have been unable to see it."

When he paused, the boys could hear, very faintly, the drone of a plane overhead. Sandy looked up toward the roof, jaw clenched.

"I'll be going now," Gosset's voice went on gently. "But several of my men will remain outside here, in case you need anything-water, or food perhaps. Just open the door and express your wants, whatever they may be." Again he chuckled. "Of course," he added, lowering his voice a little, so that the boys instinctively strained to hear, "if you prefer to keep the doors closed, we will find it necessary to open them ourselves, when it becomes convenient. I'm sure you realize that that will be by no means an impossible feat. Good-by." There were three playfully light taps on the door, in farewell, and then there was silence.

Sandy loosened his clenched jaws. "I'd like to get my hands on him for about three minutes. That's all-just three minutes!"

"He's clever," Ken said, half under his breath.

Overhead, again, the circling plane droned faintly. Ken, standing near the convertible, struck it lightly with a balled fist. The car was their only protection against the men outside. And yet if the car itself were outside it could serve as a signal to the planes above.

They should have arranged things very differently, he thought. They should certainly have arrived at the hospital in Gonzalez's black sedan instead of in their own car. The sedan would form a sturdier blockade than the little red convertible, and at the same time they could be using its radio apparatus to-

Ken's crazily wandering thoughts stopped suddenly and he swung around to clamp a tight grip on Sandy's arm. "Sandy! What was that story you told me once about the time you and Bert were fooling with an old spark coil? Didn't you say you messed up the radio reception for a couple of blocks around your house?"

"Huh? What story?" Sandy stared at him, bewildered by the sudden question.

"You must remember!" Ken shook his arm. "It happened before I knew you. But you told me you and Bert were trying to make some sort of a machine that would administer electric shocks, and the sparks from the machine interfered-"

"Oh, sure. We got hold of an old Ford spark coil and-" Sandy's voice stopped abruptly and then rose to a near shout. "Ford spark coil!" He ripped himself free from Ken's grasp and ran to the old car. He opened the hood with such violence that it fell to the floor with a noisy clatter.

"Meesters," Roberto said faintly from his perch, "is trouble come now?"

Sandy waved a rust-smeared hand at him. "Don't you worry, Roberto," he said. "Trouble is going away now."

He was brushing at the thick layer of cobwebs that overlay the coil-box cover, and then opening the clasps and lifting the cover up. The beam from the flashlight in Ken's shaking hand illuminated the four wooden boxes inside the larger box-the four wooden boxes that enclosed the spark coils.

"Trouble is going away now, we hope," Sandy breathed quietly. As if he were handling a stick of dynamite, he drew one wooden box slowly out of its place. "If only it still works," he whispered. "If only it still works!"

CHAPTER XV

DESPERATE ERROR

They stood there for a moment staring at the small wooden box that might have the magical power of summoning help. It didn't look like much, Ken thought. Certainly it bore no resemblance to the coil Sandy had pointed out to him under the hood of their own convertible. Its size was about half the size of an ordinary cigar box, and there was some sort of mechanism on top-a flat springy piece of metal that moved up and down, like half a seesaw, when Sandy gingerly touched the free end. Ken supposed that the dirt-encrusted nuts and screws set into the box top controlled the movement of the springy piece of metal. But he couldn't even guess at the purpose of the several metal disks he saw, set flush into the wooden sides of the box. To his unknowing eyes the most noticeable thing about the whole contraption was the fact that all the metal surfaces were dull and corroded, and that the wooden box itself appeared to be warped from long years of dampness.

"Is it any good at all?" Ken demanded finally.

"How do I know?" Sandy snapped back. Fear and uncertainty put a sharp rasp in his voice. "How can I tell until I've tried it out?"

"Well, try it out then." The strain was telling on Ken too. "Don't just stand there."

"Here." Sandy thrust the box at him. "If you're in such a hurry do it yourself!"

In the next instant they both realized what was happening to them. Sandy shook his head. "Sorry, Ken," he muttered. Ken shoved the box gently back toward his friend. "I'm sorry," he said. "I just wish I knew enough about things like that to be able to help you."

"Don't worry." Sandy was setting the box carefully on the floor. From his pocket he pulled a stub of a pencil and the small Spanish dictionary which they had had so little opportunity to use. "We'll both have plenty to do when I figure out where to start. Just give me a couple of minutes-and a lot of luck." He bit the end of the pencil for a moment and then he began to draw a diagram on a blank page at the back of the dictionary.

Ken watched briefly. The lines and squiggles on the paper were meaningless to him. He forced himself to move away, to leave Sandy alone. Roberto gave him a small scared smile and Ken walked over to him.

"Feeling better?" Ken asked, ruffling the youngster's black hair. And when Roberto nodded, Ken found another question to ask him-and then another. Roberto's fearfulness gave way in the comfort of Ken's presence close beside him. He talked eagerly about his widowed mother, who had a small taco stand on the square, and about his three brothers and three sisters, all younger than himself.

But in spite of Ken's best efforts he could only give Roberto the surface of his attention. He was acutely aware of the minutes ticking slowly away, one by one, and the complete silence behind him that indicated Sandy was still struggling over his diagram.

"O.K.," Sandy said suddenly, and Ken swung swiftly around. "I know as much now as I'll ever know."

Ken started toward him, his hands itching for action, any kind of action. Then he heard Roberto's quivering intake of breath at being left alone again. Ken turned back. "Come on, Roberto," he said, lifting the youngster down. "We have to help Sandy now." Roberto's black eyes thanked him silently.

Sandy held out the small sheet of paper. "This is the idea," he said. "If we can-"

Ken, looking at the maze of penciled lines, interrupted him. "It would take you all day to explain it to me," he said. "Just tell me what to do."

"O.K. I'm not sure I could explain it, anyway." Sandy flashed him a brief glance of grim amusement. "Get the fifty-foot flash-bulb extension wire out of my camera case and scrape the insulation off one end of the wire. You'll need this." He handed Ken his pocketknife. "Then wrap the bare copper end of the wire around the handle of one of those five-gallon kerosene cans we saw here somewhere. You'll have to scrape the rust off the handle first, so the connection will be good. The can and the wire are going to be our antenna. Fasten the can to the end of one of those old planks and raise it as high up in the air as you can. Got it?"

Ken nodded. "Come on, Roberto," he said. "I'll find a screw driver and you can clean off the handle of the can."

It was good to have something to do. They worked in silence, all of them. Sandy was bent over the coil box, using a nail file to polish the metal disks set flush with its surface. Roberto scraped busily away at the handle of the kerosene can. And Ken found the wire in Sandy's camera case and carefully removed the insulation from a six-inch length at one end of it.

Time went quickly now. In what seemed a very few minutes Ken was twisting the bright copper end of his wire around the newly bright handle of the kerosene can. Then he slung the can over one end of one of the splintery wooden planks and held it firmly in place with a loop of wire. Carefully he raised that end of the plank high in the air and let it come to rest against the wall. He made sure the lower end was firmly set into one of the cracks between the stones of the floor.

Sandy glanced over and saw that he had finished. "All right," he said. "Now bring the free end of the wire here. We have to make a ground connection, and that means we're going to have to pry up one of these stones." His foot tapped a spot about ten feet to one side of the convertible. "This one looks as if it might be fairly easy to move. Try the jack handle on it."

"Right." Ken found the jack handle and set to work. Roberto tried to help him, but there was little he could do. The ground around the stone was packed nearly as hard as the stone itself, and Roberto's screw driver scraped away only tiny particles of dust. At first Ken thought he was making little more headway himself, but gradually he found he could dig the jack handle far enough in so that he could begin to worry the stone very slightly.

He was only vaguely aware, as he sweated at his task, that Sandy was equally busy. The redhead was scraping clean another length of extension wire from his camera case. Then he cut the bare copper wire into shorter pieces, and wrapped the pieces around the coil box, in such a way that each wire was in contact with one of the metal disks in the box's walls.

Ken gave one last powerful lift with the jack handle and the stone rose up. He jammed his foot against it, and Roberto's small hands pushed strongly, to keep it from falling back again into its hole. A moment later Ken heaved it clear out and toppled it back onto the adjoining stone. The hole it left smelled dank.

"The stone's out," Ken reported, breathing heavily. He dashed sweat from his forehead with the back of a dirty hand. "Now what?"

"Bury the end of this wire at the bottom of the hole." Sandy handed him a short length of wire with a shiny stretch of bare copper at its end. "Then pour water over the dirt until it's good and wet."

Ken looked at him. "Water? Have we got water in a thermos?" It struck him that he was painfully thirsty.

"Not that I know of," Sandy said shortly. "But there's water in the car radiator."

"Oh-sure." Ken swallowed and forced himself to think of the job at hand. With the screw driver he scraped a groove in the hard earth at the bottom of his hole, laid the wire in it, and covered it up. Then he took one of the other kerosene cans, pried off its rusted lid, and used it as a container for the water he drained out of the convertible's radiator. He wasted cupfuls of the precious liquid because it was difficult to direct the flow into the small opening in the can's top.

Sandy, working close beside him, was removing a spark plug from the convertible's engine. "Save all you can of that," he muttered. "We'll need it."

For the first time in many long minutes a voice shouted to them from outside. "Getting hungry in there?" it taunted. "Or thirsty? We've got plenty of sandwiches and stuff out here." A derisive laugh punctuated the words. "All you've got to do is open up."

"Friendly, aren't they?" Sandy said furiously under his breath.

Ken swallowed again, trying not to think of his own thirst. Had the men outside heard their conversation? he wondered. But he reminded himself that he and Sandy had been speaking quietly, and he knew that only a raised voice could penetrate those heavy doors.

"Real friendly," he agreed. "Glad they're enjoying themselves." He bit the words off hard. "But he who laughs last-"

"Sure," Sandy said. "Let's just hope it's us." He carried the spark plug away with him and placed it and the coil box on a plank which he laid beside the hole in the floor. Then he began to connect wire after wire, until he seemed to be sitting in the middle of a wildly tangled confusion. One wire ran to the coil from the cigar lighter on the convertible's dashboard. Two ran from the coil to the spark plug. One connected the spark plug to the makeshift antenna. And still another ran from the metal body of the spark plug to the ground wire Ken had buried in the earth.

Ken came over with the can of water. He took one look at the maze of wires and then looked away. If he'd known what the job involved, he thought, he might not have had the courage to suggest that Sandy tackle it. Carefully Ken poured water into the hole, until the earth in which the ground wire was buried was a small sea of sticky mud.

"Now what?" he asked.

Sandy glanced down at the mud and nodded. "This is about it," he said then. He was kneeling before the plank and he ran his tongue nervously over his lips as he looked up at Ken.

Roberto was watching them both with tense, wide-eyed interest.

"I'm getting power to run the thing from the convertible," Sandy explained. He pointed to a pair of wires whose bright ends were a scant half inch apart. "When I touch those two wires together, current from the convertible's battery will flow through the primary of the coil."

Ken wished Sandy would dispense with the explanation, but he sensed that his friend was deliberately delaying for one last moment the trial of his laboriously constructed mechanism.

"That will set the vibrator in motion," Sandy went on, "which will generate a high voltage in the secondary of the coil. This will make a spark jump across the gap in the spark plug. And this spark will send radio waves out through the antenna. Understand?"

Ken shook his head. "No. But I don't have to. As long as you understand it, that's all that matters."

"I hope I do." Sandy spoke the words almost silently. And then his right hand moved toward one of the wires. Grasping it between thumb and forefinger, he moved it gently toward the other wire a fraction of an inch away.

The wires touched. A faint blue spark showed. But there was no answering spark at the spark plug.

Sandy looked quickly up at Ken and then back at the coil again. Once more he brought the two wires into contact. Again a feeble spark was created, but the plug itself remained dead.

Beads of perspiration stood out clearly on Sandy's forehead. He had to clear his throat before he could speak.

"I don't even know what's wrong," he said finally. "Of course the coil itself might have been exposed to dampness for too many years."

Ken made himself speak calmly, as if they had all the time in the world. "There were four of those boxes in the Ford, weren't there? Maybe another one of them is all right."

"Maybe." Sandy was staring fixedly at his maze of wires. He seemed only half-conscious of what Ken was saying.

"I'll get one," Ken said firmly. "I'll clean up those little disks, the way you did, and-"

"Wait a minute!" Sandy's voice crackled with renewed hope. He was peering so closely at some part of the coil that his red hair almost touched the floor. "Here's some contact points I forgot to clean. That could be-" He didn't bother finishing the sentence. He was giving all his attention to the delicate task of working the nail file back and forth between the tiny points on the coil's vibrator. Without looking up, he murmured, "Flashlight."

Ken snatched up the light and knelt down to hold it on the spot where Sandy was working. Sandy moved the vibrator gently up and down, making certain that the two newly bright nubs of metal met each other squarely.

"O.K.," he said finally. "We'll try it again." He wiped damp hands on his trousers, took a deep breath, and then picked up the wire between his fingers. He flicked it forward and it touched the wire from the coil.

An angry buzz sounded from the vibrator, and across the spark-plug gap a blue spark leaped, crackling noisily.

Sandy held the wires together for a long second. The spark snarled and quivered, hot and blue.

"You did it!" Ken's hand gripped Sandy's knee violently. "You did it!"

A faint ghost of a triumphant smile lighted Sandy's face, and he flicked the two wires together several times, as if still unable to believe what he had achieved.

Roberto cautiously moved closer. His bright eyes reflected the boys' excitement. "Now we can talk to the police?" he whispered. "Now we can ask them to come and take away the men who wait out there?"

Ken and Sandy stared at each other for a long incredulous moment. Sandy finally spoke the staggering thought that was in both their minds. "What dopes we are!" he groaned. "We've got this all rigged up-and we don't know any code! What good is it?" On the last words his voice rose and cracked.

From something he had read long ago, printed letters on a page leaped into Ken's mind. He waited an instant, afraid to rely on this sudden recollection. Then he knew that it would be better to take a chance than to discard all their hard work in complete despair.

"I know the code for-" His voice was thin and uncertain. He started over, firmly. "I know the code for SOS, the international distress signal. Anyway, I think I do-three dots, three dashes, three dots."

Sandy stared at him. Slowly his face became illuminated. "You know," he said softly, "I think you're right." Without another word he bent over his mechanism again. He brought the two wires together and then parted them, three times in quick succession. Each time they touched, the spark crackled. Then he made three longer contacts, and followed them with another trio of short ones.

"That's it, all right," he breathed. "That's the S O S signal." He went through the routine once more.

Zzz-zzz-zzz. Zzzzzzz-zzzzzz-zzzzzz. Zzz-zzz-zzz.

His hands were steady now. His face was set in concentrated purpose. "Switch to our parking lights," he told Ken briefly. "We have to save the battery for this." Then, carefully, timing his signals, he began to send again.

"Check." Ken leaped for the car and the wide glow of the headlights reduced itself to two small beams that flattened themselves against the big doors. In the dimness that now filled the whole big room the little sparks glowed more brightly. Ken stationed himself beside Roberto, with a reassuring arm across the slight shoulders, and they both watched and listened as Sandy kept steadily on with his task. Five long minutes went by.

Ken found himself picturing the police station, and the activity that might be taking place there now because their signal had crackled its way through the police radio receiver. But suppose the receiver wasn't turned on? And even if it was, were their signals strong enough to interrupt normal reception?

Suddenly he struck his forehead with his fist. "We can at least find out if we're getting through," he said, running the few steps to the car again. It had belatedly occurred to him that they could check the effects of their sparks on their own radio. He flipped the switch, keeping the volume low. "Any idea where I should turn to on the dial?" he asked Sandy.

"It shouldn't make any difference," Sandy told him, pausing briefly. "These sparks ought to be blanketing the entire dial-if they're doing anything at all." He went to work again.

And suddenly the car's radio speaker erupted violently. In perfect time with Sandy's sparks, it snapped and crackled.

"You're sending!" Ken didn't have to say the words aloud. Sandy, too, had heard the echo of his carefully spaced sparks.

Ken turned the dial. The crackling followed wherever he moved. "It's all over!" Ken reported. "They can't miss it! You must be ruining reception all over town!"

But Sandy shook his head. "We can't be sure how far the effects are felt," he said. "They may not reach those planes in the air. They may not even reach the police station. And if not, we're wasting our time." But he kept grimly on, changing hands when one grew too unsteady for the delicate task.

Ken looked at his watch. It was noon. What were Mort Phillips and Gonzalez doing? If they were hearing these signals, would they realize where they came from? Surely they would at least suspect that the boys might be sending them out. And in that case they probably would already have their patrols scouring the town of Rio Claro, trying to run them down. They would- Of course!

"Roberto!" Ken said suddenly. "What is the frequency of the local radio station?"

Roberto blinked. "The-? I do not understand, senor."

"Come here a minute," Ken told him. And when Roberto climbed into the car beside him, Ken said, "Can you find the Rio Claro station on this dial?"

"That is what you ask me? But yes-it is here." Roberto's small fingers twisted the dial until the pointer was set at one thousand kilocycles.

Faintly, behind the noisy static of the sparks, Ken could hear music. Then the music stopped and he heard the shadow of a voice. He leaned closer.

"Sandy!" he said suddenly. "Stop transmitting for a minute." He turned the volume up as the crackle of the sparks ceased.

An instant later Sandy was beside the car too. There was no mistaking Mort Phillips' clear voice.

"Holt and Allen? Holt and Allen? This is Phillips. This is Phillips. We're picking up an S O S. We're picking up an S O S. If you are sending this signal, reply by transmitting five dots. Reply by transmitting five dots."

Sandy was back at the transmitter before Phillips had given the order a second time. His wrist flicked five times, and five times the speaker crackled. Then he stopped.

"Got it!" The relief and triumph in Phillips' tone was evident. "Nice going-mighty nice going. Now listen closely. Can you answer this message in Morse code? Answer two dots for Yes and one dot for No."

Grimly Sandy tapped out the brief negative.

For a moment the speaker was silent, as if Phillips were gathering himself to face a more difficult problem than he had expected. Then he began to speak again.

"Using two dots for Yes, one for No, tell us this: Are you being held somewhere by force?"

Sandy sent out two quick dots.

"Do you know where you are?" Phillips asked.

Again Sandy transmitted the double signal that meant Yes.

The radio was silent for the space of a breath. Then Phillips said, "We're trying to trace your position through your transmitter, but that's a slow process. So is this Yes-and-No question business. We can communicate faster if I give you the international code signals. O.K.? Have you got pencil and paper with you?"

Sandy signaled in the affirmative while Ken rummaged frantically in the glove compartment and came up with a sheaf of yellow copy paper, left there from some recent Advance assignment. Sandy waved his pencil stub in the air and Roberto grabbed it quickly and hurried back to the car to give it to Ken.

"Ready?" Phillips asked.

Again Sandy signaled Yes.

"All right," Phillips said. "Here goes. Send a single dash after every letter-I'll give you time-so that our direction finders can keep looking for you. The code for the letter A is dot-dash."

Ken wrote it down and Sandy sent the requested dash signal.

"B is dash three dots."

Less than three minutes later Phillips was saying, "That's it. Got them all?"

Ken said, "Check" to Sandy, and Sandy tapped out a Yes.

"Right," Phillips said. His voice sounded taut. "Then tell us where you are. But keep sending dashes until you're ready to transmit."

Sandy's weary finger started a steady slow series of buzzes, while Ken hurried to his side, the flashlight in his hand.

"It ought to be enough to say just 'private hospital,'" Ken said quickly. "I'll give it to you letter by letter."

Sandy broke off the monotonous buzzes and began to send the dots and dashes that Ken recited, pausing long enough between each letter so that there could be no possible confusion.

When the fifteen letters were completed, Phillips' startled voice came through the loud-speaker:

"The private hospital here in Rio Claro?"

Sandy tapped out the two dots for Yes.

A blur of voices sounded through the speaker. The boys strained to listen and heard several staccato syllables in Gonzalez's accented English. Phillips was obviously conferring with him.

"Are you being held in the main building of the hospital?" Phillips asked finally.

Sandy buzzed a sharp single dot for No.

"In the clinic building near the road?" Gonzalez was apparently relaying to Phillips the layout of the hospital. But before the boys could answer that question, Phillips changed his mind. "No-that method's too slow. Can you give us your exact location?"

Sandy tapped out a Yes, waited an instant, and then transmitted, at Ken's dictation, two more words: underground garage.

Again there was a blur of talk over the receiver, and then Phillips said, "Right! We're on our way! We'll be there in five minutes. Keep your chins up!"

Ken and Sandy both slumped back on their heels and stared at each other. Wide foolish grins replaced the expressions of tense anxiety that they had both been wearing for what felt like weeks. Ken reached out and drew Roberto close.

"It's all right," he said. His voice was slightly unsteady. "It's all right, Roberto. The police are coming. They'll be here in a few minutes and then we'll be out of this place."

"That is good." Roberto's chin was trembling again.

It was a moment before they realized that the slight noise somewhere in the background of their enormous relief was a light tapping at the door. By the time they recognized its significance, the gentle voice of Gosset was speaking again through the wooden barrier.

"Very clever," it said. "But not quite clever enough, of course. Naturally we were receiving your signals, and the answers of your friends. You didn't think of that?"

He waited, laughing softly. "I thought not. And you underestimated me in another way too. You thought I would be so foolish as to hide you on the hospital grounds. Tut-tut, you might have given me more credit than that! It was elementary to transfer you to another location while you were unconscious."

Ken's mind could scarcely absorb the staggering news. They were not in the underground garage on the hospital grounds! That meant that their message to Phillips had been useless-had been worse than useless.

"In fact," Cosset was continuing cheerfully, "your friends will find nothing whatever to interest them when they reach the hospital. Even our latest patient, Mr. Baron, has been moved. We regretted the necessity, but your stupid blundering made it imperative. And now, unfortunately-it's really most inconvenient-we shall have to speed up our plans so far as you are concerned. We shall have to put you out of our way immediately- and permanently, I need not add."

"You want me to shoot through the door?" Joe's voice, asking the question, sounded eager.

"You always were a fool, Joe," Gosset told him gently. "Can you shoot blindly through three inches of oak and expect to do any damage? Of course not. Use the ax- quickly!"

The heavy thud of a sharp blade biting into timber put a period to Cosset's command. Incongruously, at the same moment, the Rio Claro radio station resumed its interrupted program, and the strains of a lively folk dance filled the air.

CHAPTER XVI

FIGHTING FIRE WITH FIRE

The sound of the ax's blow brought Ken and Sandy both out of the paralysis that had held them rigid during Gosset's speech. They spoke simultaneously, as they faced each other above the makeshift transmitter over which they had unwittingly flashed false information to the only men who could save them now.

"How can we-?" Sandy began.

"Send out the S O S again!" Ken said.

Sandy's fingers fumbled toward the wires and a moment later the long and short buzzes of the distress signal, sparking their way out into space, echoed noisily as crackling interruptions to the merry music flowing from the car's radio loud-speaker. The second blow of the ax thudded heavily.

On the final buzz of the second SOS signal the music broke off abruptly. The voice of the young police officer, Pedro Montez, took its place.

"Holt and Allen!" it said sharply. "This is Pedro Montez, standing by here. Have received your signal. Please explain."

Ken's mind had been working furiously. He was ready with the first message for Sandy to relay. Swiftly he dictated the dots and dashes that spelled out: not at hospital.

The blows of the ax were falling rhythmically now.

When they heard the voice of Montez again, it was harsh with amazement. "You are not at the hospitall" Then, as if Montez mistrusted his own understanding of the signals, he added, "This is your message?"

Sandy tapped out the two brief dots for Yes.

"Then where are you?" Montez demanded. But immediately, as if realizing that this question might waste time, he said, "Never mind. Answer this question: Do you know where you are?"

The wires under Sandy's hand touched once for No.

There was a brief pause. Then Montez said decisively, "I will transmit your message immediately to Phillips and Gonzalez. Also to our planes. They will resume trying to locate your transmitter. Continue to send the SOS signal to guide them. I will stand by here. Maintain contact."

Just as his voice fell silent the air was rent with a loud-splitting sound. Sandy's fingers faltered at their task. The bright edge of an ax glittered on the inner surface of the right-hand door. It was approximately at eye level, and in the center of the big panel, inside the heavy framework that gave the door extra thickness around its edges. It stayed there a moment, like a tiny streak of lightning in a dark sky, and then it disappeared. The ax had been pulled free, ready for the next blow.

In the three-second tick of time, before it thudded home again, Ken held out his hand, palm forward, to halt Sandy's transmitting. And in the silence he heard it-the drone of a plane somewhere overhead.

The ax struck the timber with a sharp crack, but Ken scarcely noticed. He was consulting the sheet of copy paper on which he had scribbled down the international code signals. "Send this," he told Sandy urgently. And he dictated the dots and dashes that spelled out: plane overhead.

Montez answered almost immediately. "Received your message: Plane overhead. Am relaying. Keep transmitting."

The axhead appeared again. This time a long sliver of wood, perhaps an inch wide and more than six feet long, splintered away from the door at the force of the impact. It fell onto the hood of the convertible, remaining attached to the timber of the door only at its lower end, as if on a hinge. A shaft of bright sunlight came with it, and in the narrow opening the boys could clearly see the glint of the ax blade as it was jerked free and withdrawn.

Cosset's henchman had made the first successful breach in the wooden wall that separated him from his victims.

Ken's mind was racing. Montez knew now that a plane was above the place where they were being held. But if several planes were taking part in the search, would it be clear immediately which one was directly above the boys' prison? And did that one plane have a direction finder accurate enough to pinpoint the place?

Another sliver of wood splintered inward, alongside the first, creating a gap nearly three inches wide. But almost immediately the broader beam of light was partially blocked. Ken realized that a body was being pressed against the outside of the opening. The pale oval of a face told him that Gosset or one of his men was peering into the prison, finding the exact location of its unarmed defenders. Then the body moved away.

Suddenly Ken knew what would replace it. He lunged across the floor to the pile of bricks alongside the convertible and grabbed one in his right hand. He stood erect and waiting, his arm up and back.

In the background of his consciousness he heard Sandy's signals buzzing their steady pattern. It was impossible to tell whether there was a plane throbbing above them now or not.

Ken stiffened. He was seeing what he had expected to see-the muzzle of an automatic thrust through the gap in the door, aimed directly at Sandy's crouched body.

"Get down!" Ken shouted. And in the same instant he hurled the brick.

It struck the gun just as it went off. The muzzle tilted high and disappeared from sight as the bullet thudded dully into one of the planks that formed the roof. Bits of whitewash drifted down from the ceiling like snow.

Sandy's signals had stopped. His pale face stared toward the door. Roberto, nearby, was a small frozen statue of fright.

"Keep sending!" Ken snapped at Sandy. "Roberto," he added, "hand me more bricks. Quickly!"

Sandy's hand was shaking. It was a moment before he could bring the two tiny points of wire in contact. He paused after two ragged buzzes and started over, more steadily.

Roberto was running across the floor, instinctively crouched low like a frightened puppy. But he found the bricks and handed two up to Ken, one for each hand. Ken kept his eye fixed steadily on the bright sunlit gap in the door.

Several voices rose outside, mingled in argument. Gosset's finally drowned out the others, although for a moment Ken didn't recognize the suddenly thin high-pitched tone. Cosset's inhuman gentleness had vanished. It had been replaced by an equally inhuman rage.

"Then make the hole bigger! You helpless idiot!" It was almost a scream.

"Not me. I'm getting out of here-now!" It was Joe who answered. "As long as that plane's gone away, I think we should-"

A shot rang out. "Next time I won't be playing, Joe," Cosset told him. "Get back here and stay here. Nobody's leaving until we get rid of those kids! Al, you take the ax!"

Again the glinting axhead flashed into view and thudded into the wood.

"Did you hear that?" Sandy's hand had fallen to his side. "The plane's gone!" The tone of his voice, as well as his motionless fingers, announced his hopelessness. "We're sunk!"

As if to confirm his statement another jagged piece of wood crashed forward out of the door. In the newly enlarged opening Al's contorted face showed clearly.

Instantaneously Ken hurled another brick. It zoomed unerringly through the aperture. The face jerked rearward and disappeared. Al's voice rose in a bellow of rage.

"Sandy, keep sending!" Ken shifted another brick to his right hand and reached his left for the one Roberto held ready. The small boy's eyes were as round as marbles. Ken didn't dare look down at him, for fear of betraying his thoughts. His mind told him that Sandy was right-that they were fighting a pitifully losing battle. But he refused to face what must be the inevitable outcome, the grim fate that Cosset had planned for him and his friend and young Roberto.

"Keep sending!" he repeated. "How can they find us if we don't keep transmitting?"

"But they'll never-"

Ken cut him off. "Keep sending. And I've got another idea, too. Roberto, can you throw these bricks?"

"Not so hard as you," Roberto answered in a small voice.

"Never mind. It doesn't have to be hard-it isn't far to the door if you stand here." With a hand on Roberto's shoulder he turned the little figure so that it faced the door. Then he grabbed his list of code signals out of his pocket and knelt down by Sandy. "Now send this," he said.

Sandy glanced at him out of haggard eyes, but he didn't argue. Automatically he sent out the thirteen signals that Ken dictated.

Ken jumped to his feet as he finished, pulling off his shirt and ripping a sleeve out of it as he did so.

"What was the message?" Sandy asked. "And what-"

"Holt and Allen!" The radio, long silent except for the rasp of Sandy's spark signals, erupted into sudden life. "Is this your message: Watch for smoke?"

"Smoke!" Sandy gasped.

"That's right," Ken snapped back. "Answer Yes."

After a brief startled interval Sandy tapped out the two sparks.

Ken was standing beside the convertible, opening the gas-tank cap.

"Right!" Pedro Montez almost shouted the word. "We will watch! Am alerting the planes immediately!"

Ken jerked the gas-tank cap free and frantically stuffed into the small opening the sleeve he had torn from his shirt. He left the cloth dangling in the gasoline as he raced to Sandy's side to pick up the jackknife.

In the enlarged opening Al's contorted face showed clearly.

With it in his hand he ran to the old Ford and began hacking away at its ancient tires. Flakes of aged, brittle rubber came away at every slash of the blade. When he had a small pile of them he gathered them up in both hands and ran to place them on the hearth of the forge.

Little Roberto gave a frightened gasp. The brick he had thrown had banged harmlessly against the wooden door, wide of its mark. Beyond the jagged hole, now nearly a foot wide, was Cosset's rage-contorted face. Ken, back at the convertible, paused to stoop down, grab up a brick, and hurl it with all his strength. Gosset's face drew away as the missile flew toward him, but not quite in time. His howl of pain told Ken that the brick must at least have grazed his ear.

"You're doing fine, Roberto," Ken said. "Just keep throwing. I'll be back to help in a minute."

Then Ken pulled his torn sleeve, dripping now with gasoline, out of the tank of the red car. Cupping it in is palms he returned to the hearth, squeezed the inflammable liquid over the rubber, and tossed the soaked sleeve on top of the little pile. He wiped his hands swiftly on his shirt, fumbled in his pocket for a match, scratched it on the stone and tossed it as the flame flared.

The gasoline fumes ignited with a violent roar. A wave of searing red rose toward the ceiling, billowing outside the masonry hood and licking upward at the dry rafters and planks. Then the flames receded. But the rubber had already caught fire. A dense cloud of black choking smoke was eddying up the funnel-shaped chimney.

Ken raced back to Roberto's side. The boy stood poised and ready, part of a brick clutched in his fingers. No face was showing at the opening now. Al was apparently trying to hack at the door from a position slightly to one side. Not all of his blows were effective, but further jagged splinters of wood had torn away.

"I'll take over, Roberto," Ken said. "Here's a knife. You go and cut more pieces of rubber from those old tires-see?-and throw them on the fire."

Roberto nodded in swift comprehension and trotted away.

Suddenly a plump white hand appeared in the opening. It was clutching a gun. Ken let fly. The gun went off, and once more a bullet crashed into the ceiling from a muzzle that had been knocked upward at the last moment. The hand that held the gun was dashed against the jagged edge of wood and Gosset's voice rose in a thin scream of agony. Slowly the hand holding the gun was withdrawn from sight.

"Chief!" Joe shouted. "There's smoke coming out of the chimney! They've got a fire in there! The planes'll see it and-! Chief, let's get in the helicopter and take off!"

The blows against the doors had ceased. "Joe's right, chief." Al, too, now sounded terrified. "Let's get out of here while we still can!"

"We'll leave when I say so and not before!" Pain had further increased the note of uncontrolled rage in Gosset's voice. "Get at that door!"

Gosset was obviously more of a menace than any threat of outside danger. The protests stopped abruptly and once again the ax beat its rhythmic thud against the wood.

"Good!" Gosset shrieked. "Faster! Faster!"

The car's loud-speaker spoke suddenly, the first words lost in the crackle of Sandy's steady signals, until Sandy realized what was happening and broke off.

"-see smoke! Both planes have reported sudden column of black smoke!" Montez was saying excitedly. "One plane is now almost directly above it and will dive low over the spot within fifteen seconds. Signal if you hear the dive! Send two dots for Yes if you hear the dive!"

Ken started to count. One-two-three-

There was a throbbing overhead now. The throbbing grew louder. Suddenly it changed to the thunderous shaking roar of a power dive. Even the heavy stone walls of the building seemed to quiver.

The roar diminished quickly as the plane rose again. But already Sandy was sending out a series of paired dots, one after the other.

"Bueno!" Montez shouted over the radio. "Then we know your location. It is less than two miles from the police station. Phillips and Gonzalez are on their way to you now!"

Something sang past Ken's ear. An instant later he heard a bullet zing into the stone wall behind him. As he instinctively flung himself to the floor he took one last look at the hole. No face was in sight beyond it. Gosset, he realized, must be standing to one side of the hole and shooting through it at an angle.

"Get close to the front wall!" Ken said swiftly to the others. As he spoke he leaped to his feet and ran, to flatten himself against the wall to the right of the doors -one of the two locations in the room which Gosset would have most difficulty in hitting with his wild shots. "Come here, Roberto!"

But Sandy had grabbed Roberto and was pressing the small body against the wall, beside his own, to the left of the doors.

"Keep that ax going!" Gosset's insane rage drove his voice to a shriek. He fired again and this shot clanged noisily against the convertible. "I said to get that door down!"

Al's ax had been silent. He didn't use it again now. Instead he said, "But, chief, you heard that voice over the radio! You saw that plane! It means-!"

The panic-stricken plea was cut short by a maniacal scream from Gosset. "Use that ax! Or I'll-!"

He broke off his command as the metal blade struck the wood again. But this time the blow was lighter, as if Al were too concerned over the gun in Cosset's hand to give his strength to the task.

And now Gosset began to fire through the hole again, still from his safe position. The shots covered a wide arc of the room directly in front of Ken, to within a few feet of where he stood. Then, suddenly, the aim shifted. Gosset had moved to the other side of the hole and was firing from the opposite angle. Ken looked over the convertible's hood to where Sandy and Roberto stood. The bullets were slanting across in front of them, but there was a margin of safety between the deadly slugs and the two figures flat against the wall. The noise of their explosion was deafening in the enclosed place.

At any moment, Ken knew, Gosset would realize the futility of what he was doing. Then, too insane with fury to reckon his own danger, he would place himself in front of the hole and reach inside to take a true aim.

They would have to be ready. Ken moved quietly forward along the convertible, stopping on the way to pick up as many bricks as he could carry. He reached the red car's rear fender and moved on around to stand beyond the old Ford. There he dropped the bricks on the floor, keeping one in his right hand. By peering over the old car's hoodless engine, he could look past the convertible's flank, directly at the widening gash in the door, now nearly two feet across.

Sandy had seen what Ken was doing. He jerked his head frantically to signal Ken back to his previous safe position. But Ken stayed where he was.

"Faster!" Gosset was chanting. "Faster!"

Twice more the ax thudded. But the second time it was not withdrawn from the wood.

"I can't," Al gasped. "I'm finished!"

“I told you-!”

"I don't care what you told me!" Al broke in, still fighting for air. "Use the ax yourself-or are you afraid of getting that close to the door?"

"Afraid!" The voice rose still higher and cracked. And suddenly Gosset appeared in the center of the gap, gun raised, pointed straightforward.

Ken's head, peering around the convertible, was directly in the line of fire. Instantly his arm flashed forward. All his strength, all his fear, all his anger was behind that throw. The jagged brick shot forward past the convertible and straight through the hole in the door.

Ken had intended to duck the moment the brick left his hand, but he found himself watching spellbound as his projectile flew toward its mark. It struck the gun, knocking it sideways, and crashed against Gosset's chest.

The small mouth in the round pink face opened foolishly. In that instant he looked as harmless as a stuffed doll. But Ken knew that as long as Gosset was alive he was as harmless as a cobra. He reached down for another brick.

He didn't throw it. Joe's stocky body suddenly appeared alongside Gosset. He clamped his hand over the gun Cosset still held and wrenched it free. Then his other arm went around Cosset's neck and the gun came down like a club on the silver-white hair.

Cosset's head fell forward. Joe released his hold. The plump body sagged.

"Come on, Al!" Joe yelled. "Start the helicopter!"

Joe lunged out of sight to the left of the gap in the door. Another pair of fleeing footsteps joined his.

Without knowing it, Ken had moved forward. He reached the door just as he heard the roar of a car's motor. An instant later a big black sedan swerved into view and skidded to a stop in a cloud of dust.

"Ken! Sandy!" Phillips' voice shouted before Ken saw the stocky body tumble out of the car.

"We're here!" Ken called. "But we're all right!" He poked his head through the opening and looked in the direction he knew Joe and Al had fled. "Over there! Quick! They've got a helicopter!"

He didn't know Sandy had joined him until he heard his friend's voice, shouting above his own. "Don't worry about us! Just don't let them get away!"

Phillips swerved in his headlong run. Gonzalez and three uniformed figures were behind him.

"Senores," Roberto said in a small voice, "the police have found us, no?"

Ken reached back and pulled him close. "The police have found us, yes!" He felt Sandy's arm fall on top of his own, across Roberto's shoulders. "Everything's all right now, Roberto," he added. "The trouble's all over."

The big clock on the wall at police headquarters said two o'clock, and the bells of the cathedral were booming the same hour across the sunny plaza. Ten minutes earlier the cool, stone-floored room in the ancient municipal palace had been crowded with Cosset and his associates and the police officers and deputies to whom they had been handcuffed. But now the prisoners had all been locked in the half-dozen cells somewhere to the rear of the office, and the deputies and officers had been dismissed. Only the chief of police himself remained, together with young Pedro Montez. With the help of Phillips and Gonzalez they were still working on the prisoner admission forms spread out on the chiefs desk -more forms than the Rio Claro chief had ever been responsible for at any one time. He was still incredulous at the thought that his quiet peaceful town had harbored the headquarters of an important criminal ring.

Ken and Sandy were already at work on what they knew would be one of the biggest stories of their lives. Sandy was preparing captions for the rolls of film he had taken during the past hour and a half, and Ken was typing his copy on a borrowed typewriter.

The phone rang and Ken looked up expectantly. He knew that Phillips and Gonzalez had both placed several long-distance calls, some of which had still not been completed. But when Ken had placed a call to his,father, the police chief had told the switchboard operator to put it through the moment Richard Holt had been reached, even if it meant delaying one of the official communications.

A moment later Ken was taking the phone from the chief's hands and grinning into it. "Dad?" he said. He listened briefly to his father's warm voice coming over the wire and then he answered, "No, we're not in Mexico City-not yet. We-er-we got held up a little. We ran into quite a story here."

Five minutes went by and Ken was still talking. Phillips and Gonzalez had abandoned their work and were frankly listening, because there still were many details of the past several hours which they had not yet had time to learn from the boys. Some of the facts Ken told his father, however, was information that he and Sandy had not known until they returned to the police station.

Once Richard Holt interrupted to ask, "But where was this place where you and Sandy were being held?"

"There was a time," Ken told him, "when it looked as if we might not live to learn the answer to that question ourselves." Then he went on hurriedly, to forestall his father's comments of alarmed anger. "A ruined hacienda just over the hill from the hospital. There are several big stone buildings there, some of them partially destroyed. Gosset used one of them as a hangar for his helicopter. He sent Baron and all the rest of his gang over there as soon as he intercepted Sandy's message about the hospital, and if they'd taken off right then, they might have escaped. But Gosset obviously went completely crazy when things began to go wrong-so Phillips and Gonzalez were able to round up the whole lot of them. They recovered the money from Baron, too. Baron himself is in the hospital now. The others are all here in the municipal jail temporarily."

When the whole story had been fully outlined, and Richard Holt had been assured that Ken and Sandy were both safe and unharmed, Ken added, "So will you send a flash on this to Granger, Dad? I've already started typing the yarn, and Sandy has some pictures." He grinned suddenly. "You might tell Granger, by the way, that Sandy is going to put in a bill for a lot of ruined extension wire."

Sandy leaned close to speak into the mouthpiece. "That's right. Tell Granger to brace himself. It's likely to cost him two dollars-maybe even three!"

Richard Holt's chuckle drifted over the wire. Sandy backed away from the phone, to make room for Ken again, and Phillips asked curiously, "Who's Granger?"

"Manager of the New York office of Global News," Sandy told him. He grinned. "Wish I could see his face when he gets my bill. He'll start yelling his head off. He used to scare Ken and me to death, until we learned that he did it on purpose, to cover up the fact that he'd give us the shirt off his back if he thought we needed it."

Ken was reading into the phone from his notes now, giving his father a brief run-down on Gosset and his most important associates.

"No," he said, "Gosset has no previous criminal record. But Roland Spander, the doctor, has-two years ago he served time for doing plastic surgery on criminals. And George Toby-that's the man with the green-flamed lighter, who first talked to us at the border-is wanted in the United States for counterfeiting. He's, too, had his face changed. And so have two of the others-Anthony Talburt and Gerald Burke-who are wanted for that Greystone Bank robbery in New York last year."

"Hmmm." Ken could hear his father's pencil racing over paper, nearly four hundred miles away in Mexico City. "Quite a haul. And, as you said, quite a story. But if I can't let you two out of my sight for a single day, without your running into-"

"Dad," Ken interrupted hastily, "I can't stay on the phone much longer. Phillips and Gonzalez both have calls coming through."

"I see," Richard Holt said dryly. "When I'm on the point of making a paternal remark about the trouble you get into, then suddenly it's time for you to hang up.

Very well. But I'll finish this speech when I see you. When will that be, by the way?"

"We'll phone you again tonight," Ken promised him, "when things get settled here. But you should have Sandy's pictures and my story pretty soon. Captain Gonzalez is going to put them on a plane for us and they should reach you in-" he looked at Gonzalez, who held up two stubby fingers-"in about two hours, Dad."

"Good. I'll put it right on the wire to Granger. And when I see you two, I'll put you-well, never mind," Richard Holt concluded. "Just try to take care of yourselves until tonight, will you?"

"Yes, Dad."

Phillips shook his head. "It must be a strain, being the father of one of you two. I've nearly turned gray in the last six hours, worrying about you. At the end of a year-"

"But everything worked out all right," Sandy reminded him. "Except," he added thoughtfully, "that we haven't had any lunch and I'm likely to die of starvation.”

Gonzalez was getting to his feet. "Mort," he said with mock solemnity, "I see we must rescue these young men again. I, personally, will undertake the mission, as a small gesture of gratitude for services rendered by Holt and Allen. I will buy them the finest arroz con polio available in Rio Claro." He glanced at the chief. "Is there a good restaurant in town-a really good one?"

His answer came unexpectedly from a bench in the corner, where Roberto had been curled up, contentedly sucking at a new stick of sugar cane presented to him by young Pedro Montez.

"Si, sefior," Roberto said eagerly, scrambling off the bench. "There is a most good restaurant. I will take you there." He turned to Ken and Sandy, "I am still your guide, no?"

Ken and Sandy, grinning proudly and affectionately at the little boy who had so bravely shared their grim ordeal, answered him in a single voice, "You are still our guide, yes!"

The warmth of the bright sun chased away the last grim memories of the vicious, half-crazed Gosset, as they all walked lightheartedly across the plaza in the wake of a happily chattering Roberto.

"It'll be a relief to sit down to a meal and have all the time we need to enjoy it," Sandy said.

"Time," Gonzales pointed out, "is the most precious thing in the world, especially when you do not have any."

Ken and Sandy grinned at him cheerfully, aware of the vacation leisure stretching out before them. But they would remember his words in a very different mood, at a moment in the near future, when time was the one thing they didn't have-when they were perilously involved in the adventure that would become famous as The Mystery of the Grinning Tiger.

THE END

THE MYSTERY OF THE GREEN FLAME

A KEN HOLT MYSTERY, No. 10

By Bruce Campbell

Side note: The authors of this tale, using a different pseudonym, wrote another tale of mystery and adventure on a tourist trip to Mexico, called THE RIDDLE OF THE HIDDEN PESOS by Martin Colt.