INHUMAN ERROR

When the dreadnought Hamilcar Barca came out of the inhuman world of plus-space into the blue-white glare of Meitner's Sun the forty men and women of the dreadnought's crew were taut at their battle stations, not knowing whether or not the whole berserker fleet would be around them as they emerged. But then they were in normal space, seconds of tune were ticking calmly by, and there were only the stars and galaxies to be seen, no implacable, inanimate killers coming to the attack. The tautness eased a little.

Captain Liao, his lean frame strapped firmly into the combat chair in the center of the dreadnought's bridge, had brought his ship back into normal space as close to Meitner's Sun as he dared-operating on interstellar, c-plus drive in a gravitational field this strong was dangerous, to put it mildly-but the orbit of the one planet of the system worth being concerned about was still tens of millions of kilometers closer to the central sun. It was known simply as Meitner's Planet, and was the one rock in the system habitable in terms of gravity and temperature.

Before his ship had been ten standard seconds in normal space, Liao had begun to focus a remote-controlled telescope to bring the planet into close view on a screen that hung before him on the bridge. Luck had brought him to the same side of the sun that the planet happened to be on; it showed under magnification on the screen as a thin illuminated crescent, covered with fluffy-looking perpetual clouds. Somewhere beneath those clouds a human colony of about ten thousand people dwelt, for the most part under the shelter of one huge ceramic dome. The colonists had begun work on the titanic project of converting the planet's ammonia atmosphere to a breathable one of nitrogen and oxygen. Meanwhile they held the planet as an outpost of some importance for the interstellar community of all Earth-descended men.

There were no flares of battle visible in space around the planet, but still Liao lost no time in transmitting a message on the standard radio and laser communications frequencies. "Meitner's Planet, calling Meitner's. This is the dreadnought Hamilcar Barca. Are you under attack? Do you need immediate assistance?"

There came no immediate answer, nor could one be expected for several minutes, the time required for signals traveling at the speed of light to reach the planet, and for an answer to be returned.

Into Liao's earphones now came the voice of his Detection and Ranging Officer. "Captain, we have three ships in view." On the bridge there now sprang to life a three-dimensional holographic presentation, showing Liao the situation as accurately as the dreadnought's far-ranging detection systems and elaborate combat computers could diagram it. He smoothed graying hair back from his high forehead with an habitual gesture, and tried to determine what was going on.

One ship, appearing as a small bright dot with attached numerical coordinates, was hanging relatively motionless in space, nearly on a line between Hamilcar Barca and Meitner's Planet. The symbol chosen for it indicated that this was probably a sizable craft, though not nearly as massive as the dreadnought. The other two ships visible in the presentation were much smaller, according to the mass-detector readings on them. They were also both considerably closer to the planet, and moving toward it at velocities that would let them land on it, if that was their intention, in less than an hour.

What these three ships were up to, and whether they were controlled by human beings or berserker machines, was not immediately apparent. After sizing up the situation for a few seconds, Liao ordered full speed toward the planet-full speed, of course, in the sense of remaining in normal space and thus traveling much slower than light-and to each of the three ships in view he ordered the same message beamed: "Identify yourself, or be destroyed."

The threat was no bluff. No one took chances where berserker machines were concerned. They were an armada of robot spaceships and supporting devices built by some unknown and long-vanished race to fight in some interstellar war that had reached its forgotten conclusion while men on Earth were wielding spears against the sabertooth tiger. Though the war for which the berserker machines had been made was long since over, still they fought on across the galaxy, replicating and repairing themselves endlessly, learning new strategies and tactics, refining their weapons to cope with their chief new enemy, Earth-descended man. The sole known basic in their fundamental programming was the destruction of all life, wherever and wherever they could find it.

Waiting for replies from the planet and the three ships, hoping fervently that the berserker fleet that was known to be on its way here had not already come and gone and left the helpless colony destroyed, Liao meanwhile studied his instruments critically. "Drive, this is the Captain. Can't you get a little more speed on?"

The answer came into his earphones: "No, sir, we're on the red line now. Another kilometer-per-second and we'll blow a power lamp or worse. This is one heavy sun, and it's got some dirty space around it." The ship was running now on the same space-warping engines that carried it faster than light between the stars, but this deep within the huge gravitational well surrounding Meitner's Sun the power that could be applied to them was severely restricted. The more so because here space was dirty, as the Drive Officer had said, meaning the interplanetary matter to be encountered within this system was comparatively dense. It boiled down to the fact that Liao had no hope of overtaking the two small vessels that fled ahead of him toward the planet. They, as it were, skimmed over shoals of particles that the dreadnought must plow through, flirted with reefs of drive-wrecking gravitational potential that it must approach more cautiously, and rode more lightly the waves of the solar wind that streamed outward as always from a sun.

Now the minimum time in which the largest, nearest vessel might have replied to the dreadnought's challenge had come and gone. No reply had been received. Liao ordered the challenge repeated continuously.

The Communications Officer was speaking. "Answer from the planet, Captain. It's coming in code. I mean the simple standard dot-dash code, sir, like the emergency signals. There's a lot of noise around too, maybe that's the only way they can get a signal through." Powerfully and crudely modulated dot-and-dash signals could carry intelligence through under conditions where more advanced forms of modulation were simply lost.

Communications was on the ball; already they had the decoded words flowing across a big screen on the bridge.

DREADNOUGHT ARE WE EVER GLAD TO HEAR FROM YOU STOP ONE OF THE TWO LITTLE SHIPS CLOSING IN ON US MUST BE A BERSERKER STOP BETTER TRANSMIT TO US IN DOT-DASH CODE STOP LOTS OF NOISE BECAUSE SUN IS FLARING AND WE COULDNT READ YOUR SIGNAL VERY WELL

The letters abruptly stopped flowing across the screen. The voice of the Communications Officer said: "Big burst of noise, Captain, signals from the planet are going to be cut off entirely for a little while. This sun is a very active flare star…just a moment, sir. Now we're getting voice and video transmissions beamed to us from both small ships. But the signals from both ships are so garbled by noise we can't make anything out of them."

"Beam back to them in dot-dash, tell them they'll have to answer us that way. Repeat our warnings that they must identify themselves. And keep trying to find out what the ground wants to tell us." The Captain turned his head to look over at his Second Officer in the adjoining combat chair. "What'd you think of that, Miller? 'One of the two little ships must be a berserker'?"

Miller, by nature a somewhat morose man, only shook his massive head gloomily, knitted heavy brows, and saved his speech to make a factual report. "Sir, I've been working on identifying the two active ships. The one nearest the planet is so small it seems to be nothing more than a lifeboat. Extrapolating backward from its present course and position indicates it may well have come from the third ship, the one that's drifting, a couple of hours ago.

"The second little ship is a true interstellar vessel; could be a one-man courier ship or even somebody's private yacht. Or a berserker, of course." The enemy came in all shapes and sizes.

Still no answer had been returned from the large, drifting ship, though the dreadnought was continuing to beam threatening messages to her, now in dot-dash code. Detection reported now that she was spinning slowly around her longest axis, consistent with the theory that she was some kind of derelict. Liao checked again on the state of communications with the planet, but they were still cut off by noise.

"But here's something, Captain. Dot-and-dash is coming in from the supposed courier. Standard code as before, coming at moderate manual speed."

Immediately, more letters began to flow across the number-one screen on the bridge:

I AM METION CHONGJIN COMMANDING THE ONE MAN COURIER ETRURIA EIGHT DAYS OUT OF ESTEEL STOP CANNOT TURN ASIDE I AM CARRYING VITAL DEFENSE COMPONENT FOR COLONY STOP LIFEBOAT APPROX 12 MILLION KM TO MY PORT AND AHEAD IS SAID BY GROUND TO BE CLAIMING TO BE THE SHIP CARRYING THE DEFENSE COMPONENT THEREFORE IT MUST REALLY BE A BERSERKER STOP IT WILL PROBABLY REACH COLONY AND BOMB OR RAM IT BEFORE I GET THERE SO YOU MUST DESTROY IT REPEAT DESTROY THE BERSERKER QUOTE LIFEBOAT UNQUOTE MOST URGENT THAT YOU HIT IT SOON END MESSAGE

Miller made a faint whistling noise. "Sounds fairly convincing, Chief." During briefing back at base three standard days ago they had been informed of the fact that the colony on Meitner's Planet was awaiting shipment of a space inverter to complete and activate their defensive system of protective force-screens and beam-projecting weapons. Until the inverter could be brought from Esteel and installed the colony was virtually defenseless; the dreadnought had been dispatched to offer it some interim protection.

Liao was giving orders to Armament to lock the c-plus cannon of the main battery onto the lifeboat. "But fire only on my command." Turning back to the Second, he said: "Yes, fairly convincing. But the berserkers might have found out somehow that the space inverter was being rushed here. They might even have intercepted and taken over the courier carrying it. We can't see who we're talking to on that ship or hear his voice. It might have been a berserker machine that just tapped out that message to us."

The Communications Officer was on again. "Bridge, we have the first coded reply from the lifeboat coming in now. Here it comes on your screen."

WE ARE HENRI SAKAI AND WINIFRED ISPAHAN CARRYING THE DEFENSE MATERIEL NAMELY SPACE INVERTER THEY NEED ON THE PLANET STOP OUR SHIP THE WILHELMINA FROM ESTEEL WAS SHOT UP BY THE BERSERKER TWO DAYS AGO WHEN IT ALMOST CAUGHT US STOP THE BERSERKER OR ANOTHER ONE IS HERE NOW ABOUT 11 MILLION KM TO OUR STARBOARD AND A LITTLE BEHIND US YOU MUST KEEP IT FROM GETTING TO US OR TO THE PLANET WHERE MAYBE IT COULD RAM THE DOME END MESSAGE

"Communications," the Captain snapped, "how is this coming through? I mean, does this also seem like someone sending manual code?"

"No, sir, this is very rapid and regular. But if you mean, Captain, does that prove they're not human, it doesn't. In a lifeboat the transmitter often has a voice-to-code converter built in."

"And conversely a berserker could send slowly and somewhat irregularly, like a man, if it wanted to. Thank you." The Captain pondered in silence for a little while.

"Sir," Miller suggested, "maybe we'd better order both small ships to stop, until we can overtake and board them."

The Captain turned his head to look at him steadily, but remained silent.

Miller, slightly flustered, took thought and then corrected himself. "Now I see the problem more fully, sir. You can't do that. If one of them is really carrying the space inverter you don't dare delay him for a minute. A berserker fleet may materialize in-system here at any moment, and is virtually certain to arrive within the next six to eight hours. Our ship alone won't be able to do more than hit-and-run when that happens. Our fleet can't get here for another day. The colony will never survive the interval without their space inverter installed."

"Right. Even if I sent a fast launch ahead to board and inspect those ships, the delay would be too much to risk. And that's not all, Second. Tell me this-is this conceivably just some misunderstanding, and both of those ships are really manned by human beings?"

"Not a chance," the Second answered promptly. "They both claim to be carrying the space inverter, and that can't be true. Those things just aren't ordered or built in duplicate or triplicate, and they both claim to be bringing it from the planet Esteel… the next question is, can both of our little targets be berserkers? Trying to psych us into letting one of them get through? I'll keep trying to reach the ground, see if they can shed any more light on this." Miller swiveled away in his heavy chair.

"Good going."

In their earphones Communications said: "Here's more from the ship that calls itself Etruria, Bridge."

"Put it right on our screen."

REPEAT COLONY SAYS LIFEBOAT IS ALSO CLAIMING TO BE THE HUMAN ONE STOP THEY MUST BE A BERSERKER IMPERATIVE YOU STOP THEM WHAT DO YOU WANT ME TO DO TO PROVE IM HUMAN STOP REPEAT MY NAME IS METION CHONGJIN IM ALONE ON BOARD HERE WIFE AND KIDS AT HOME ON ESTEEL IF THAT MEANS ANYTHING TO YOU STOP REPEAT HOW CAN I PROVE TO YOU IM HUMAN END MESSAGE

"Easy," Captain Liao muttered to himself. "Father a human child. Compose a decent symphony. In the next forty minutes or so." That was approximately the time left before at least one of the ships would be able to reach the planet. Liao's mind was racing to formulate possible tests, but getting nowhere. Berserkers had awesome powers, not only as physical fighting machines, but as computers. They could not counterfeit either human appearance or human behavior successfully when under close observation; but Liao was not certain that a battery of psychologists with several days to work in would be able to say with certainty whether it was a living man or a lying berserker that answered their questions in dot-dash.

Time passed. Hurtling through silence and near-emptiness at many kilometers per second, the ships very slowly changed the positions of their symbols in the huge holographic presentation on the bridge.

"Now more from the Wilhelmina's lifeboat, Captain."

"Run that on the top of the screen, will you, and put any more that comes in from Etruria on the bottom."

HENRI AND WINIFRED HERE COLONY TELLS US OTHER SHIP IS CLAIMING TO BE FROM ESTEEL CARRYING DEFENSE COMPONENTS AND REQUESTING LANDING INSTRUCTIONS STOP IT MUST BE LYING IT MUST BE A BERSERKER MAYBE THE SAME ONE THAT ATTACKED OUR SHIP TWO DAYS AGO…

The message ran on and despite some irrelevancies and redundancies it outlined a coherent story. The Wilhelmina (if the story was to be believed) had been on an interstellar cruise, carrying a number of young people on some kind of student exchange voyage or post-graduate trip. Somewhere on the outskirts of the solar system that contained the heavily industrialized planet Esteel, a courier ship bound for Meitner's had approached and hailed the Wilhelmina, had in fact commandeered her to complete the courier's mission. Berserkers were in pursuit of the courier and had already damaged her extensively.

… AND WE WERE ON OUR WAY HERE WITH THE INVERTER WHEN ONE OF THE BERSERKERS ALMOST CAUGHT UP AGAIN TWO STANDARD DAYS AGO STOP WILHELMINA WAS BADLY SHOT UP THEN CREW ALL KILLED WE ARE ONLY TWO LEFT ALIVE TWO HISTORY STUDENTS WE HAD TERRIBLE PROBLEMS ASTROGATING HERE BUT MADE IT STOP LIVING IN LIFEBOAT AND WORKING RIDDLED SHIP IN SPACESUITS YOU CANT STOP US NOW AFTER ALL WE HAVE BEEN THROUGH STOP YOU MUST DESTROY THE BERSERKER SHIP WE WILL REACH PLANET BEFORE IT DOES I THINK BUT IT WILL BE ABLE TO HIT THE DOME BEFORE THE SPACE INVERTER CAN BE INSTALLED STOP WE ARE GOING TO KEEP SENDING UNTIL YOU ARE CONVINCED WE ARE HUMAN…

The message from the lifeboat went on, somewhat more repetitiously now. And at the same time on the bottom of the screen more words from Etruria flowed in:

I HAVE TRIED TO CATCH THE BERSERKER LIFEBOAT AND SHOOT IT DOWN BUT I CANT ITS UP TO YOU TO STOP IT STOP WHAT DO YOU WANT ME TO DO TO PROVE IM HUMAN…

The Second Officer sighed lightly to himself, wondering if, after all, he really wanted his own command.

"Communications, beam this out," the Captain was ordering. "Tell them both to keep talking and give us their life histories. Birth, family, education, the works. Tell them both they'd better make it good if they want to live." On buttons on the arm of his chair he punched out an order for tea, and a moment later tea came to him there through a little door, hot in a capped cup with drinking tube attached. "I've got an idea. Second. You study the background this so-called Esteeler spaceman Metion Chongjin gives us. Think up someplace you might have known him. We'll introduce you to him as an old friend, see how he copes."

"Good idea, Chief."

"Communications here again, Bridge. We've finally gotten another clear answer back from the ground. It's coming through now, we'll put it in the middle of your number-one screen."

… IN ANSWER TO YOUR QUESTION NO THEY CANT BOTH BE BERSERKERS STOP AN HOUR AGO THERE WAS A BRIEF LETUP IN THE NOISE AND WE GOT ONE CLEAR LOOK AT A HUMAN MALE FACE ALIVE AND TALKING COGENTLY ANSWERING OUR QUESTIONS NO POSSIBILITY THAT WAS A BERSERKER BUT UNFORTUNATELY BOTH SUSPECT SHIPS WERE SENDING ON THE SAME FREQ AND WE DONT KNOW FROM WHICH ONE THAT VOICE AND PICTURE CAME BUT WE DO KNOW THAT ONE OF THEM IS HUMAN…

"Damnation, how they've botched things up. Why didn't they ask the two men to describe themselves, and see which description fit what they saw?"

"This is Communications again, fridge. They may have tried asking that, sir, for all we know. We've lost contact with the ground again now, even on code. I guess the solar wind is heating up. Conditions in the ionosphere down there must be pretty fierce. Anyway, here's a little more from the Etruria":

WHAT DO YOU WANT ME TO DO TO PROVE IM HUMAN RECITE POETRY MARY HAD A LITTLE LAMB STOP SAY PRAYERS I NEVER MEMORIZED ANY OF THEM STOP OKAY I GIVE UP SHOOT US BOTH DOWN THEN END MESSAGE

The Second Officer thumped a fist on the arm of his massive chair. "A berserker would say that, knowing that its fleet was coming, and the colony would be defenseless if we stopped the space inverter from getting to it."

Liao shrugged, and helped himself to a massive slug of tea. "But a human might say that too, being willing to die to give the colony a few more hours of life. A human might hope that given a few more hours some miracle might come along, like the human fleet getting here first after all. I'm afraid that statement didn't prove a thing."

"I… guess it didn't."

After another good slug of tea, Liao put in a call to Astrogation.

"Chief Astrogator here, sir."

"Barbara, have you been listening in on this? Good. Tell me, could those two supposed history students, probably knowing little science or technology, have brought that ship in here? Specifically, could they have astrogated for two days, maybe fifty or sixty light years, without getting lost? I suppose the ship's autopilot was knocked out. They said they were living in the lifeboat and working the damaged ship in spacesuits."

"Captain, I've been pondering that claim too, and I just don't know. I can't say definitely that it would be impossible. If we knew just how badly that ship was damaged, what they had to work with, we could make a better guess."

The Captain looked back at his situation hologram. The apparently inert hulk that he had been told was the Wilhelmina was considerably closer now, lying as it did almost in Hamilcar Barca's path toward Meitner's Planet. The dreadnought was going to pass fairly near the other ship within the next few minutes. "As to that, maybe we can find out something. Keep listening in, Barbara." Turning to the Second Officer, Liao ordered: "You're going to be taking over the Bridge shortly, Miller. I want us to match velocities with that supposed hulk ahead, and then I'm going over to her, in hopes of learning something."

"It might be booby-trapped, Captain."

"Then we'll have an answer, won't we? But I don't expect an answer will be found that easily. Also get me a reading on exactly how much time we have left to decide which ship we're going to fire on."

"I've already had the computers going on that, sir. As of now, thirty-two and a quarter minutes. Then the lifeboat will either be down in atmosphere or around on the other side of the planet, and out of effective range in either case. The courier will take a little longer to get out of effective range, but…" He gestured helplessly.

"The courier being slower won't help us. We have to decide in thirty-two minutes."

"Chief, I just had an idea. If the lifeboat was the berserker, since it's closer to the planet, wouldn't it have tried before we got here to head off the courier from the planet… oh. No good. No offensive weapons on the lifeboat."

"Right, except perhaps it has one bloody big bomb, meant for the colony. While the courier ship doubtless has some light armament, enough to deal with the lifeboat if it got in range. Still nothing proven, either way."

In another minute the silent ship ahead was close enough for telescopes on the dreadnought to pick out her name by starlight. It was Wilhelmina, all right, emblazoned near one end of her cigar-like shape. The dreadnought matched velocities with her smoothly, and held position a couple of kilometers off. Just before getting into a launch with a squad of armed marines to go over and inspect her, Liao checked back with the Bridge to see if anything was new.

"Better hear this before you go," Miller told him. "I just introduced myself to Chongjin as an old buddy. This is his reply, quote: 'I honestly don't remember your name if I ever knew it, stop. If this was a test I guess I passed. Hurrah! Now get on with it and stop that berserker on the lifeboat…' and then the signal faded out again. Chief, our communication problems are getting steadily worse. If we're going to say anything more to either of those ships we'd better send it soon."

"How many minutes left, Second?"

"Just eighteen, sir."

"Don't waste any of 'em. This ship is yours."

"I relieve you, sir."

No signs of either life or berserker activity were apparent on the Wilhelmina as the launch crossed the space separating her from the dreadnought and docked, with a gentle clang of magnetic grapples. Now Liao could see that the reported damage was certainly a fact. Holes several meters in diameter had been torn in Wilhelmina's outer hull. Conditions inside could hardly be good.

Leaving one man with the launch, Liao led the rest of his small party in through one of the blasted holes, swimming weightlessly, propelling themselves by whatever they could grip. He had briefed the men to look for something, anything, that would prove or disprove the contention that humans had driven this ship for the last two days since she had been damaged.

Fifteen and a half minutes left.

The damage inside was quite as extensive as the condition of the hull had indicated. Their suit lights augmenting the sharp beams that Meitner's distant sun threw into the airless interior, the boarding party spread out, keeping in touch by means of their suit radios. This had undoubtedly been a passenger ship. Much of the interior was meant as living quarters, divided into single and double cabins, with accommodations for a couple of dozen people. What furnishings remained suggested luxury. So far, everything said by the lifeboat's occupant was being proved true, but Liao as yet had no clear evidence regarding that occupant's humanity, nor even a firm idea of what evidence he was looking for. He only hoped that it was here, and that he would recognize it at first sight.

The interior of the ship was totally airless now, having been effectively opened to the stars by the repeated use of some kind of penetration weapon. The ruin was much cleaner than any similarly damaged structure on a planet's surface could be, loose debris having been carried out of the ship with escaping air, or separated from her when her drive took her outside of normal space and time, between the stars.

"Look here, Captain." The Lieutenant in charge of the marine squad was beckoning to him. Liao followed, on a vertiginous twisting passage through the wreck.

Near the center of the slender ship the Lieutenant had found a place where a wound bigger than any of the others had pierced in, creating in effect an enormous skylight over what had been one of the largest compartments on board. Probably it had been a lounge or refectory for the passengers and crew. Since the ship was damaged this ruined room had evidently provided the most convenient observation platform for whoever or whatever had been in control: a small, wide-angle telescope, and a tubular electronic spectroscope, battery-powered and made for use in vacuum, had been roughly but effectively clamped to the jagged upper edge of what had been one of the lounge's interior walls and now formed a parapet against infinity.

The Lieutenant was swiveling the instruments on their mountings. "Captain, these look like emergency equipment from a lifeboat. Would a berserker machine have needed to use these, or would it have gear of its own?"

The Captain stood beside him. "When a berserker puts a prize crew on a ship, it uses man-sized, almost android machines for the job. It's just more convenient for the machines that way, more efficient. So they could quite easily use instruments designed for humans." He swung his legs to put his magnetic boots against the lounge's soft floor, so that they held him lightly to the steel deck beneath, and stared at the instruments, trying to force more meaning from them.

Men kept on searching the ship, probing everywhere, coming and going to report results (or rather the lack of them) to Liao at his impromptu command post in what had been the lounge. Two marines had broken open a jammed door and found a small airless room containing a dead man who wore a spacesuit; cause of death was not immediately apparent, but the uniform collar visible through the helmet's faceplate indicated that the man had been a member of Wilhelmina's crew. And in an area of considerable damage near the lounge another, suitless, body was discovered wedged among twisted structural members. This corpse had probably been frozen near absolute zero for several days and exposed to vacuum for an equal length of time. Also its death had been violent. After all this it was hard to be sure, but Liao thought that the body had once been that of a young girl who had been wearing a fancy party dress when she met her end.

Liao could imagine a full scenario now, or rather two of them. Both began with the shipload of students, eighteen or twenty of them perhaps, enjoying their interstellar trip. Surely such a cruise had been a momentous event in their lives. Maybe they had been partying as they either entered or were about to leave the solar system containing the planet Esteel. And then, according to Scenario One, out of the deep night of space came the desperate plea for help from the damaged and harried courier, hotly pursued by berserkers that were not thought to be in this part of the galaxy at all.

The students would have had to remain on board the Wilhelmina, there being noplace for them to get off, when she was commandeered to carry the space inverter on to Meitner's Planet. Then urgent flight, and two days from Meitner's a berserker almost catching up, tracking and finding and shooting holes in Wilhelmina, somewhere in the great labyrinth of space and dust and stars and time, in which the little worlds of men were strange and isolated phenomena. And then the two heroic survivors, Henri and Winifred, finding a way to push on somehow.

Scenario Two diverged from that version early on, and was simpler and at first glance more credible. Instead of the Wilhelmina being hailed by a courier and pressed into military service, she was simply jumped by berserkers somewhere, her crew and passengers efficiently wiped out, her battered body driven on here ahead of the main berserker fleet in a ploy to forestall the installation of the space inverter and demolish the colony before any help could reach it Scenario One was more heroic and romantic, Two more prosaic and businesslike. The trouble was that the real world was not committed to behaving in either style but went on its way indifferently.

A man was just now back from inspecting Wilhelmina's control room. "Almost a total loss in there, sir, except for the Drive controls and their directional settings. Artificial gravity's gone, Astrogator's position is wiped out, and the autopilot too. Drive itself seems all right, as far as I can tell without trying it."

"Don't bother. Thank you, mister."

Another man came to report, drifting upside-down before the captain in the lack of gravity. "Starboard forward lifeboat's been launched, Captain. Others are all still in place, no signs of having been lived in. Eight-passenger models."

"Thank you," Liao said courteously. These facts told him nothing new. Twelve minutes left now, before he must select a target and give the command to fire. In his magnetic boots he stood before the telescope and spectroscope as their user had done, and looked out at the stars.

The slow rotation of the Wilhelmina brought the dreadnought into view, and Liao flicked his suit radio to the intership channel. "Bridge, this is Captain. Someone tell me just how big that space inverter is. Could two untrained people manhandle it and its packing into one of those little eight-passenger lifeboats?"

"This is the Armaments Officer, sir," an answer came back promptly. "I used to work in ground installations, and I've handled those things. I could put my arms around the biggest space inverter ever made, and it wouldn't mass more than fifty kilograms. It's not the size makes 'em rare and hard to come by, it's the complexity. Makes a regular drive unit or artificial gravity generator look like nothing."

"All right. Thank you. Astrogation, are you there?"

"Listening in, sir."

"Good. Barbara, the regular astrogator's gear on this ship seems to have been wiped out. What we have then is two history students or whatever, with unknown astronomical competence, working their way here from someplace two days off, in a series of c-plus jumps. We've found their instruments, apparently all they used, simple telescope and spectroscope. You've been thinking it over, now how about it? Possible?"

There was a pause. Barbara would be tapping at her console with a pencil. "Possible, yes. I can't say more than that on what you've given me."

"I'm not convinced it's possible. With umpteen thousand stars to look at, their patterns changing every time you jump, how could you hope to find the one you wanted to work toward?" Ten minutes. Inspiration struck. "Listen! Why couldn't they have shoved off in the lifeboat, two days ago, and used its autopilot?"

Barbara's voice was careful as always. "To answer your last question first, Chief, lifeboats on civilian ships are usually not adjustable to give you a choice of goals; they just bring you out in the nearest place where you are likely to be found. No good for either people or berserkers intent on coming to Meitner's system. And if Wilhelmina's drive is working it could take them between the stars faster than a lifeboat could.

"To answer your first question, the lifeboats carry aids for the amateur astrogator, such as spectral records of thousands of key stars, kept on microfilm. Also often provided is an electronic scanning spectroscope of the type you seem to have found there. The star records are indexed by basic spectral type, you know, types O, B, A, F, G, K, and so on. Type O stars, for example, are quite rare in this neck of the woods so if you just scanned for them you would cut down tremendously on the number of stars to be looked at closely for identification. There are large drawbacks to such a system of astrogation, but on the other hand with a little luck one might go a long way using it. If the two students are real people, though, I'll bet at least one of them knows some astronomy."

"Thank you," Liao said carefully, once again. He glanced around him. The marines were still busy, flashing their lights on everything and poking into every crevice. Eight minutes. He thought he could keep the time in his head now, not needing any artificial chronometer.

People had lived in this lounge, or rec room, or whatever it had been, and enjoyed themselves. The wall to which the astrogation instruments were now fastened had earlier been decorated, or burdened, with numerous graffiti of the kinds students seemed always to generate. Many of the messages, Liao saw now, were in English, an ancient and honorable language still fairly widely taught. From his own schooldays he remembered enough to be able to read it fairly well, helping himself out with an occasional guess.

captain ahab chases alewives, said one message proceeding boldly across the wall at an easy reading height. The first and third words of that were certainly English, but the meaning of the whole eluded him. Captain Liao chases shadows, he thought, and hunches. What else is left?

Here was another:

OSS AND HIS NOBLE CLASSMATES WISH THE WHOLE WORLD

And then nothingness, the remainder of the message having gone when Oss and his noble classmates went and the upper half of this wall went with them.

"Here, Captain! Look!" A marine was beckoning wildly.

The writing he was pointing to was low down on the wall and inconspicuous, made with a thinner writing instrument than most of the other graffiti had been. It said simply: Henri & Winifred.

Liao looked at it, first with a jumping hope in his heart and then with a sagging sensation that had rapidly become all too familiar. He rubbed at the writing with his suited thumb; nothing much came off. He said: "Can anyone tell me in seven minutes whether this was put here after the air went out of the ship? If so, it would seem to prove that Henri and Winifred were still around then. Otherwise it proves nothing." If the berserker had been here it could easily have seen those names and retained them in its effortless, lifeless memory, and used them when it had to construct a scenario.

"Where are Henri and Winifred now, that is the question," Liao said to the Lieutenant, who came drifting near, evidently wondering, as they all must be, what to do next. "Maybe that was Winifred back there in the party dress."

The marine answered: "Sir, that might have been Henri, for all that I could tell." He went on directing his men, and waiting for the Captain to tell him what else was to be done.

A little distance to one side of the names, an English message in the same script and apparently made with the same writing instrument went down the wall like this:

Oh Kiss

Be Me

A Right

Fine Now

Girl Sweetie

Liao was willing to bet that particular message wasn't written by anyone wearing a space helmet. But no, he wouldn't make such a bet, not really. If he tried he could easily enough picture the two young people rubbing faceplates and laughing, momentarily able to forget the dead wedged in the twisted girders a few meters away. Something about that message nagged at his memory, though. Could it be the first line of an English poem he had forgotten?

The slow turn of the torn ship was bringing the dreadnought into view again. "Bridge, this is Captain. Tell me anything that's new."

"Sir, here's a little more that came in clear from the lifeboat. I quote: "This is Winifred talking now, stop. We're going on being human even if you don't believe us, stop.' Some more repetitious stuff, Captain, and then this: 'While Henri was navigating I would come out from the lifeboat with him and he started trying to teach me about the stars, stop. We wrote our names there on the wall under the telescope; if you care to look you'll find them; of course that doesn't prove anything, does it. If I had lenses for eyes I could have read those names there and remembered them…'It cuts off again there, Chief, buried in noise."

"Second, confirm my reading of how much time we have left to decide."

"Three minutes and forty seconds, sir. That's cutting it thin."

"Thanks." Liao fell silent, looking off across the universe. If offered him no help.

"Sir! Sir! I may have something here." It was the marine who had found the names, who was still closely examining the wall.

Looking at the wall where the man had aimed his helmet light, near the deck below the mounted instruments, Liao beheld a set of small grayish indented scratches, about half a meter apart.

"Sir, some machine coming here repeatedly to use the scopes might well have made these markings on the wall. Whereas a man or woman in spacesuits would not have left such marks, in my opinion, sir."

"I see." Looking at the marks, that might have been made by anything, maybe furniture banged into the wall during that final party, Liao felt an irrational anger at the marine. But of course the man was only trying to help. He had a duty to put forward any possibly useful idea that came into his head. "I'm not sure these were made by a berserker, spaceman, but it's something to think about. How much time have we left, Second?"

"Just under three minutes, sir. Standing by ready to fire at target of your choice, sir. Pleading messages still coming in intermittently from both ships, nothing new in them."

"All right." The only reasonable hope of winning was to guess and take the fifty-fifty chance. If he let both ships go on, the bad one was certain to ram into the colony and destroy it before the other could deliver the key to the defenses and it could be installed. If he destroyed both ships, the odds were ten to one or worse that the berserker fleet would be here shortly and accomplish the same ruin upon a colony deprived of any chance of protecting itself.

Liao adjusted his throat muscles so that his voice when it came out would be firm and certain, and then he flipped a coin in his mind. Well, not really. There were the indented scratches on the bulkhead, perhaps not so meaningless after all, and there was the story of the two students' struggle to get here, perhaps a little too fantastic. "Hit the lifeboat," he said then, decisively. "Give it another two minutes, but if no new evidence turns up, let go at it with the main turret. Under no circumstances delay enough to let it reach the planet."

"Understand, sir," said Miller's voice. "Fire at the lifeboat two minutes from your order."

He would repeat the order to fire, emphatically, when the time was up, so that there could be no possible confusion as to where responsibility lay. "Lieutenant, let's get the men back to the launch. Continue to keep your eyes open on the way, for anything…"

"Yes, sir."

The last one to leave the ruined lounge-observatory, Liao looked at the place once more before following the marines back through the ship. Oh, be a fine girl, Winifred, when the slug from the c-plus cannon comes. But if I have guessed wrong and it is coming for you, at least you'll never see it. Just no more for you. No more Henri and no more lessons about the stars.

The stars…

Oh, be a fine girl…

O, B, A, F, G, K…

"Second Officer!"

"Sir!"

"Cancel my previous order! Let the lifeboat land. Hit the Etruria! Unload on that bloody damned berserker with everything we've got, right now!"

"Yessir!"

Long before Liao got back to the launch the c-plus cannon volleyed. Their firing was invisible, and inaudible here in airlessness, but still he and the others felt the energies released pass twistily through all their bones. Now the huge leaden slugs would begin skipping in and out of normal space, homing on their tiny target, far out-racing light in their trajectories toward Meitner's Planet. The slugs would be traveling now like de Broglie wavicles, one aspect matter with its mass magnified awesomely by Einsteinian velocity, one aspect waves of not much more than mathematics. The molecules of lead churned internally with phase velocities greater than that of light.

Liao was back on the dreadnought's bridge before laggard light brought the faint flash of destruction back.

"Direct hit, Captain." There was no need to amplify on that.

"Good shots, Arms."

And then, only a little later, a message got through the planet's ionospheric noise to tell them that the two people with the space inverter were safely down.

Within a few hours the berserker fleet appeared in system, found an armed and ready colony, with Hamilcar Barca hanging by for heavy hit-and-run support, skirmished briefly and then decided to decline battle and departed. A few hours after that, the human fleet arrived and decided to pause for some refitting. And then Captain Liao had a chance to get down into the domed colony and talk to two people who wanted very much to meet him.

"So," he was explaining, soon after the first round of mutual congratulations had been completed, "when I at last recognized the mnemonic on the wall for what it was, I knew that not only had Henri and Winny been there but that he had in face been teaching her something about astronomical spectroscopy at that very place beside the instruments-therefore after the ship was damaged."

Henri was shaking his youthful head, with the air of one still marveling at it all. "Yes, now I can remember putting the mnemonic thing down, showing her how to remember the order of spectral types. I guess we use mnemonics all the time without thinking about it much. Every good boy does fine, for the musical notes. Bad boys race our young girls-that one's in electronics."

The captain nodded. "Thirty days hath September. And Barbara Celarent that the logicians still use now and then. Berserkers, with their perfect memories, probably don't even know what mnemonics are, much less need them. Anyway, if the berserker had been on the Wilhelmina, it would've had no reason to leave false clues. No way it could have guessed that I was coming to look things over."

Winifred, slender and too fragile-looking for what she had been through, took him by the hand. "Captain, you've given us our lives, you know. What can we ever do for you?"

"Well. For a start…" He slipped into some English he had recently practiced: "You might be a fine girl, sweetie, and…"

And the search for truth may be the lifework of a human mind. Praise be to those who have such a purpose-truly-in their hearts!

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