There had been a time, after the war with the Eaters, when it had been customary to prey upon the slow-moving and stupid diatoms, whose exquisite and fragile glass shells were so easily burst, and who were unable to learn that a friendly voice did not necessarily mean a friend. There were still people who would crack open a diatom when no one else was looking, but they were regarded as barbarians, to the puzzle- ment of the Protos. The blurred and simple-minded speech of the gorgeously engraved plants had brought them into the category of community petsa concept which the Protos were utterly unable to grasp, especially since men admitted that diatoms on the half-frustrule were delicious.

Lavon had had to agree, very early, that the distinction was tiny. After all, humans did eat the desmids, which differed from the diatoms only in three particulars: Their shells were flexible, they could not move (and for that matter neither could all but a few groups of diatoms), and they did not speak. Yet to Lavon, as to most men, there did seem to be some kind of distinction, whether the Protos could see it or not, and that was that. Under the circumstances he felt that it was a part of his duty, as the hereditary leader of men, to protect the diatoms from the occasional poachers who browsed upon them, in defiance of custom, in the high levels of the sunlit sky.

Yet Lavon found it impossible to keep himself busy enough to forget that moment when the last clues to Man's origin and destination had been seized, on authority of his own care- less exaggeration, and borne away into-dim space.

It might be possible to ask Para for the return of the plate, explain that a mistake had been made. The Protos were creatures of implacable logic, but they respected men, were used to illogic in men, and might reverse their deci- sion if pressed We are sorry. The plate was carried over the bar and re- leased in the gulf. We will have the Bottom there searched, but...

With a sick feeling he could not repress, Lavon knew that that would be the answer, or something very like it. When the Protos decided something was worthless, they did not hide it in some chamber like old women. They threw it away efficiently.

Yet despite the tormenting of his consicence, Lavon was nearly convinced that the plate was well lost. What had it ever done for Man, except to provide Shais with useless things to think about in the late seasons of their lives? What the Shars themselves had done to benefit Man, here, in the water, in the world, in the universe, had been done by direct experimentation. No bit of useful knowledge had ever come from the plates. There had never been anything in the sec- ond plate, at least, but things best left unthought. The Protos were right.

Lavon shifted his position on the plant frond, where he had been sitting in order to overlook the harvesting of an experi- mental crop of blue-green, oil-rich algae drifting in a clotted mass close to the top Of the sky, and scratched his back gently against the coarse bole. The Protos were seldom wrong, after all. Their lack of creativity, their inability to think an orig- inal thought, was a gift as well as a limitation. It allowed them to see and feel things at all times as they werenot as they hoped they might be, for they had no ability to hope, either.

"La-voni Laa-vah-on!”

The long halloo came floating up from the sleepy depths.

Propping one hand against the top of the frond, Lavon bent and looked down. One of the harvesters was looking up at him, holding loosely the adze with which he had been split- ting free from the raft the glutinous tetrads of the algae.

"I'm up here. What's the matter?”

"We have the ripened quadrant cut free. Shall we tow it away?”

'Tow it away," Lavon said, with a lazy gesture. He leaned back again. At the same instant, a brilliant reddish glory burst into being above him, and cast itself down toward the depths like mesh after mesh of the finest-drawn gold. The great light which lived above the sky during the day, bright- ening or dimming according to some pattern no Shar ever had fathomed, was blooming again.

Few men, caught in the warm glow of that light, could re- sist looking up at itespecially when the top of the sky itself wrinkled and smiled just a moment's climb or swim away.

Yet, as always, .Lavon's bemused upward look gave him back nothing but his own distorted, hobbling reflection, and a re- flection of the plant on which he rested.

Here was the upper limit, the third of the three surfaces of the universe. The first surface was the Bottom, where the water ended.

The second surface was the thermocline, definite enough in summer to provide good sledding, but easily penetrable if you knew how.

The third surface was the sky. One could no more pass through that surface than one could penetrate the Bottom, nor was there any better reason to try. There the universe ended. The light which played over it daily, waxing and wan- ing as it chose, seemed to be one of its properties.

Toward the end of the season, the water gradually became colder and more difficult to breathe, while at the same time the light grew duller and stayed for shorter periods between darknesses. Slow currents started to move. The high waters turned chill and started to fall. The Bottom mud stirred and smoked away, carrying with it the spores of the fields of fungi.

The thermocline tossed, became choppy, and melted away.

The sky began to fog with particles of soft silt carried up from the Bottom, the walls, the corners of the universe.

Before very long, the whole world was cold, inhospitable, flocculent with yellowing, dying creatures. The world died until the first tentative current of warm water broke the win- ter silence.

That was how it was when the second surface vanished. If the sky were to melt away . . .

"Lavoni”

Just after the long call, a shining bubble rose past Lavon.

He reached out and poked it, but it bounded away from his sharp thumb. The gas bubbles which rose from the Bottom in late summer were almost invulnerableand when some especially hard blow or edge did penetrate them, they broke into smaller bubbles which nothing could touch, leaving be- hind a remarkably bad smell.

Gas. There was no water inside a bubble. A man who got inside a bubble would have nothing to breathe.

But, of course, it was impossible to enter a bubble. The surface tension was too strong. As strong as Shar's metal plate. As strong as the top of the sky.

As strong as the top of the sky. And above thatonce the bubble was brokena world of gas instead of water? Were all worlds bubbles of water drifting in gas?

If it were so, travel between them would be out of the question, since it would be impossible to pierce the sky to begin with. Nor did the infant cosmography include any pro- visions for Bottoms for the worlds.

And yet some of the local creatures did burrow into the Bottom, quite deeply, seeking something in those depths which was beyond the reach of Man. Even the surface of the ooze, in high summer, crawled with tiny creatures for which mud was a natural medium. And though many of the en- tities with which man lived could not pass freely between the two countries of water which were divided by the thermo- cline, men could and did.

And if the new universe of which Shar had spoken existed at all, it had to exist beyond the sky, where the light was.

Why could not the sky be passed, after all? The fact that bubbles could sometimes be broken showed that the surface skin had formed between water and gas wasn't completely in- vulnerable. Had it ever been tried?

Lavon did not suppose that one man could butt his way through the top of the sky, any more than he could burrow into the Bottom, but there might be ways around <he diffi- culty. Here at his back, for instance, was a plant which gave every appearance of continuing beyond the sky; its upper fronds broke off and were bent back only by a trick of re- flection.

It had always been assumed that the plants died where they touched the sky. For the most part, they did, for frequently the dead extension could be seen, leached and yellow, the boxes of its component cells empty, floating unbedded in the perfect mirror. But some were simply chopped off, like the one which sheltered him now. Perhaps that was only an il- lusion, and instead it soared indefinitely into some other placesome place where men might once have been born, and might still live ...

Both plates were gone. "There was only one other way to find out.

Determinedly, Lavon began to climb toward the wavering mirror of the sky. His thorn-thumbed feet trampled oblivi- ously upon the clustered sheaths of fragile stippled diatoms.

The tulip-heads of Vortae, placid and murmurous cousins of Para, retracted startledly out of his way upon coiling stalks, to make silly gossip behind him.

Lavon did not hear them. He continued to climb doggedly toward the light, his fingers and toes gripping the plant-bole.

"Lavon! Where are you going? Lavoni”

He leaned out and looked down. The man with the adze, a doll-like figure, was beckoning to him from a patch of blue- green retreating over a violet abyss. Dizzily he looked away, clinging to the bole; he had never been so high before. He had, of course, nothing to fear from falling, but the fear was in his heritage. Then he began to climb again.

After a while, he touched the sky with one hand. He stopped to breathe. Curious bacteria gathered about the base of his thumb where blood from a small cut was fogging away, scattered at his gesture, and wriggled mindlessly back toward the dull red lure.

He waited until he no longer felt winded, and resumed climbing. The sky pressed down against the top of his head, against the back of his neck, against his shoulders. It seemed to give slightly, with a tough, frictionless elasticity. The water here was intensely bright, and quite colorless. He climbed another step, driving his shoulders against that enor- mous weight.

It was fruitless. He might as well have tried to penetrate a cliff.

Again he had to rest. While he panted, be made a curious discovery. All around the bole of the water plant, the steel surface of the sky curved upward, making a kind of sheath.

He found that he could insert his hand into itthere was al- most enough space to admit his head as well. Clinging closely to the bole, he looked up into the inside of the sheath, probing it with his injured hand. The glare was blinding.

There was a tind of soundless explosion. His whole wrist was suddenly encircled in an intense, impersonal grip, as if it were being cut in two. In blind astonishment, he lunged upward.

The ring of pain travelled smoothly down his upflung arm as he rose, was suddenly around his shoulders and chest.

Another lunge and his knees were being squeezed in the cir- cular vise. Another Something was horribly wrong. He clung to the bole and tried to gasp, but there wasnothing to breathe.

The water came streaming out of his body, from his mouth, his nostrils, the spiracles in his sides, spurting in tangible jets.

An intense and fiery itching crawled over the surface of his body. At each spasm, long knives ran into him, and from a great distance he heard more water being expelled from his book-lungs in an obscene, frothy sputtering. Inside his head, a patch of fire began to eat away at the floor of his nasal cavity.

Lavon was drowning:

With a final convulsion, he kicked himself away from the splintery bole, and fell. A hard impact shook him; and then the water, who had clung to him so tightly when he had first attempted to leave her, took him back with cold violence.

Sprawling and tumbling grotesquely, he drifted, down and down and down, toward the Bottom.

For many days, Lavon lay curled insensibly in his spore, as if in the winter sleep. The shock of cold which he had felt on re-entering his native universe had been taken by his body as a sign of coming winter, as it had taken the ozygen-starvation of his brief sojourn above the sky. The spore-forming glands had at once begun to function.

Had it not been for this, Lavon would surely have died.

The danger of drowning disappeared even as he fell, as the air bubbled out of his lungs and readmitted the life-giving water. But for acute desiccation and third degree sunburn, the sunken universe knew no remedy. The healing amniomc fluid generated by the spore-forming glands, after the trans- parent amber sphere had enclosed him, offered Lavon his only chance.

The brown sphere, quiescent in the eternal winter of the Bottom, was spotted after some days by a prowling ameba.

Down there the temperature was always an even 4, no matter what the season, but it was unheard of that a spore should be found there while the high epilimnion was still warm and rich in oxygen.

Within an hour, the spore was surrounded by scores of astonished protos, jostling each other to bump their blunt eyeless prows against the shell. Another hour later, a squad of worried men came plunging from the castles far above to press their own noses against the transparent wall. Then swift orders were given.

Pour Para grouped themselves about the amber sphere, and there was a subdued explosion as their trichocysts burst. The four Paras thrummed and lifted, tugging.

Lavon's spore swayed gently in the mud and then rose slowly, entangled in the fine web. Nearby, a Noc cast a cold pulsating glow over the operation, for the benefit of the baf- fled knot of men. The sleeping figure of Lavon, head bowed, knees drawn up into its chest, revolved with an absurd so- lemnity inside the shell as it was moved.

"Take him to Shar, Para.”

The young Shar justified, by minding his own business, the traditional wisdom with which his hereditary office had in- vested him. He observed at once that there was nothing he could do for the encysted Lavon which would not be classi- fiable as simple meddling.

He had the sphere deposited in a high tower room of his castle, where there was plenty of light and the water was warm, which should suggest to the estivating form that spring was again on the way. Beyond that, he simply sat and watched, and kept his speculations to himself.

Inside the spore, Lavon's body seemed to be rapidly shed- ding its skin, in long strips and patches. Gradually, his curi- ous shrunkenness disappeared. His withered arms and legs and sunken abdomen filled out again.

The days went by while Shar watched. Finally he could discern no more changes, and, on a hunch, had the spore taken up to the topmost battlements of the tower, into the di- rect daylight.

An hour later, Lavon moved in his amber prison.

He uncurled and stretched, turned blank eyes up toward the light. His expression was that of a man who had not yet awakened from a ferocious nightmare. His whole body shone with a strange pink newness.

Shar knocked gently on the walls of the spore. Lavon turned his blind face toward the sound, life coming into his eyes. He smiled tentatively and braced his hands and feet against the inner wall of the shell.

The whole sphere fell abruptly to pieces with a sharp crack- ling. The amnionic fluid dissipated around him and Shar, carrying away with it the suggestive odor of a bitter struggle against death.

Lavon stood among the shards and looked at Shar silently.

At last he said:

"SharI've been above the sky.”

"I know," Shar said gently.

Again Lavon was silent. Shar said, "Don't be humble, Lavon. You've done an epoch-making thing. It nearly cost you your life. You must tell me the restall of it.”

"The rest?”

"You taught me a lot while you slept. Or are you still op- posed to 'useless' knowledge?”

Lavon could say nothing. He no longer could tell what he knew from what he wanted to know. He had only one ques- tion left, but he could not utter it. He could only look dumb- ly into Shar's delicate face.

"You have answered me," Shar said, even more gently than before. "Come, my friend; join me at my table. We will plan our journey to the stars.”

There were five of them around Shar's big table: Shar him- self, Lavon, and the three assistants assigned by custom to the Shars from the families Than, Tanol and Stravol. The duties of these three menor, sometimes, womenunder many previous Shars had been simple and onerous: to put into effect in the field the genetic changes in the food crops which the Shar himself had worked out in little, in laboratory tanks and flats. Under other Shars more interested in metal- working or in chemistry, they had been-smudged mendig- gers, rock-splitters, fashioners and cleaners of apparatus.

Under Shar XVI, however, the three assistants had been more envied than usual among the rest of Lavon's people, for they seemed to do very little work of any kind. They spent long hours of every day talking with Shar in his chambers, poring over records, making miniscule scratch-marks on slate, or just looking intently at simple things about which there was no obvious mystery. Sometimes they actually worked with Shar in his laboratory, but mostly they just sat.

Shar XVI had, as a matter of fact, discovered certain rudi- mentary rules of inquiry which, as he explained it to Lavon, he had recognized as tools of enormous power. He had become more interested in passing these on to future workers than in the seductions of any specific experiment, the journey to the stars perhaps excepted. The Than, Tanol and Stravol of his generation were having scientific method pounded into their heads, a procedure they maintained was sometimes more painful than heaving a thousand rocks.

That they were the first of Lavon's people to be taxed with the problem of constructing a spaceship was, therefore, in- evitable. The results lay on the table: three models, made of diatom-glass, strands of algae, flexible bits of cellulose, flakes of stonewort, slivers of wood, and organic glues collected from the secretions of a score of different plants and animals.

Lavon picked up the nearest one, a fragile spherical con- struction inside which little beads of dark-brown lavaac- tually bricks of rotifer-spittle painfully chipped free from the wall of an unused castlemoved freely back and forth in a kind of ball-bearing race. "Now whose is this one?" he said, turning the sphere curiously to and fro.

"That's mine," Tanol said. "Frankly, I don't think it comes anywhere near meeting all the requirements. It's just the only design I could arrive at that I think we could build with the materials and knowledge we have to hand now.”

"But how does it work?”

"Hand it here a moment, Lavon. This bladder you see in- side at the center, with the hollow spirogyra straws leading out from it to the skin of the ship, is a buoyancy tank. The idea is that we trap ourselves a big gas-bubble as it rises from the Bottom and install it in the tank. Probably we'll have to do that piecemeal. Then the ship rises to the sky on the buoy- ancy of the bubble. The little paddles, here along these two bands on the outside, rotate when the crewtfiat's these bricks you hear shaking around insidewalks a treadmill that runs around the inside of the hull; they paddle us over to the edge of the sky. I stole that trick from the way Didin gets about. Then we pull the paddles inthey fold over into slots, like thisand, still by weight-transfer from the inside, we roll ourselves up the slope until we're out in space. When we hit another world and enter the water again, we let the gas out of the tank gradually through the exhaust tubes represented by these straws, and sink down to a landing at a controlled rate.”

"Very ingenious," Shar said thoughtfully. "But I can fore- see some difficulties. For one thing, the design lacks stability.”

"Yes, it does," Tanol agreed. "And keeping it in motion is going to require a lot of footwork. But if we were to sling a freely-moving weight from the center of gravity of the ma- chine, we could stabilize it at least partly. And the biggest ex- penditure of energy involved in the whole trip is going to be getting the machine up to the sky in the first place, and with this design that's taken care ofas a matter of fact, once the bubble's installed, we'll have to keep the ship tied down until we're ready to take off.”

"How about letting the gas out?" Lavon said. "Will it go out through those little tubes when we want it to? Won't it just cling to the walls of the tubes instead? The skin between water and gas is pretty difficult to deformto that I can tes- tify.”

Tanol frowned. "That I don't know. Don't forget that the tubes will be large in the real ship, not just straws as they are in the model.”

"Bigger than a man's body?" Than said.

"No, hardly. Maybe as big through as a man's head, at the most.”

"Won't work," Than said tersely. "I tried it. You can't lead a bubble through a pipe that small. As Lavon says, it clings to the inside of the tube and won't be budged unless you put pressure behind itlots of pressure. If we build this ship, we'll just have to abandon it once we hit our new world; we won't be able to set it down anywhere.”

"That's out of the question," Lavon said at once. "Putting aside for the moment the waste involved, we may have to use the ship again in a hurry. Who knows what the new world will be like? We're going to have to be able to leave it again if it turns out to be impossible to live in.”

"Which is your model, Than?" Shar said.

"This one. With this design, we do the trip the hard way crawl along the Bottom until it meets the sky, crawl until we hit the next world, and crawl wherever we're going when we get there. No aquabatics. She's treadmill-powered, like Tanol's, but not necessarily man-powered; I've been thinking a bit about using motile diatoms. She steers by varying the power on one side or the other. For fine steering we can also hitch a pair of thongs to opposite ends of the rear axle and swivel her that way.”

Shar looked closely at the tube-shaped model and pushed it experimentally along the table a little way. "I like that," he said presently. "It sits still when you want it to. With Than's spherical ship, we'd be at the mercy of any stray current at home or in the new worldand for all I know there may be currents of some sort in space, too, ga& currents perhaps.

Lavori, what do you think?”

"How would we build it?" Lavon said. "It's round in cross- section. That's all very well for a model, but how do you make a really big tube of that shape that won't fall in on itself?”

"Look inside, through the front window," Than said.

"You'll see beams that cross at the center, at right angles to the long axis. They hold the walls braced.”

"That 'consumes a lot of space," Stravol objected. By far the quietest and most introspective of the three assistants, he had not spoken until now since the beginning of the confer- ence. "You've got to have free passage back and forth inside the ship. How are we going to keep everything operating if we have to be crawling around beams all the time?”

"All right, come up with something better," Than said, shrugging.

"That's easy. We bend hoops.”

"Hoops!" Tanol said. "On that scale? You'd have to soak your wood in mud for a year before it would be flexible enough, and then it wouldn't have the strength you'd need.”

"No, you wouldn't," Stravol said. "I didn't build a ship model, I just made drawings, and my ship isn't as good as Than's by a long distance. But my design for the ship is also tubular, so I did build a model of a hoop-bending machine that's it on the table. You lock one end of your beam down in a heavy vise, like so, leaving the butt striking out on the other side. Then you tie up the other end with a heavy line, around this notch. Then you run your line around a windlass, and five or six men wind up the windlass, like so. That pulls the free end of the beam down until the notch engages with this key-slot, which you've pro-cut at the other end. Then you un- lock the vise, and there's your hoop; for safety you might drive a peg through the joint to keep the thing from spring- ing open unexpectedly.”

"Wouldn't the beam you were using break after it had bent a certain distance?" Lavon asked.

"Stock timber certainly would," Stravol said. "But for this trick you use green wood, not seasoned. Otherwise you'd have to soften your beam to uselessness, as Tanol says. But live wood will flex enough to make a good, strong, single-unit hoopor if it doesn't, Shar, the little rituals with numbers that you've been teaching us don't mean anything after alll”

Shar smiled. "You can easily make a mistake in using num- bers," he said.

"I checked everything.”

"I'm sure of it. And I think it's well worth a trial. Anything else to offer?”

"Well," Stravol said, "I've got a kind of live ventilating sys- tem I think should be useful. Otherwise, as I said, Than's ship strikes me as the type we should build; my own's hope”

lessly cumbersome.”

"I have to agree," Tanol said regretfully. "But I'd like to try putting together a lighter-than-water ship sometime, maybe just for local travel. If the new world is bigger than ours, it might not be possible to swim everywhere you might want to go.”

"That never occurred to me," Lavon exclaimed. "Suppose the new world is twice, three times, eight times as big as ours?

Shar, is there any reason why that couldn't be?”

"None that I know of. The history plate certainly seems to take all kinds of enormous distances practically for granted.

All right, let's make up a composite design from what we have here. Tanol, you're the best draftsman among us, sup- pose you draw it up. Lavon, what about labor?”

"I've a plan ready," Lavon said. "As I see it, the people who work on the ship are going to have to be on the job full time.

Building the vessel isn't going to be an overnight task, or even one that we can finish in a single season, so we can't count on using a rotating force. Besides, this is technical work; once a man learns how to do a particular task, it would be wasteful to send him back to tending fungi just because somebody else has some time on his hands.

"So I've set up a basic force involving the two or three most intelligent hand-workers from each of the various trades.

Those people I can withdraw from their regular work without upsetting the way we run our usual concerns, or noticeably in- creasing the burden on the others in a given trade. They will do the skilled labor, and stick with the ship until it's done.

Some of them will make up the crew, too. For heavy, un- skilled jobs, we can call on the various seasonal pools of un- skilled people without disrupting our ordinary life.”

"Good," Shar said. He leaned forward and rested linked hands on the edge of the tablealthough, because of the web- bing between his fingers, he could link no more than the fin- gertips. "We've really made remarkable progress. I didn't ex- pect that we'd have matters advanced a tenth as far as this by the end of this meeting. But maybe I've overlooked some- thing important. Has anybody any more suggestions, or any questions?”

"I've got a question," Stravol said quietly.

"All right, let's hear it.”

'Where are we going?" ‘

There was quite a long silence. Finally Shar said: "Stravol, I can't answer that yet. I could say that we're going to the stars, but since we still have no idea what a star is, that an- swer wouldn't do you much good. We're going to make this trip because we've found that some of the fantastic things that the history plate says are really so. We know now that the sky can be passed, and that beyond the sky there's a re- gion where there's no water to breathe,, the region our an- cients called 'space.' Both of these ideas always seemed to be against common sense, but nevertheless we've found that they're true.

"The history plate also says that there are other worlds than ours, and actually that's an easier idea to accept, once you've fofind out that the other two are so. As for the stars well, we just don't know yet, we haven't any information at all that would allow us to read the history plate on that sub- ject with new eyes, and there's no point in mating wild guesses unless we can test the guesses. The stars are in space, and presumably, once we're out in space, we'll see them and the meaning of the word will become clear. At least we can confidently expect to see some clueslook at all the informa- tion we got from Lavon's trip of a few seconds above the skyl "But in the meantime, there's no point in our speculating in a bubble. We think there are other worlds somewhere, and we're devising means to make the trip. The other questions, the pendant ones, just have to be put aside for now. We'll an- swer them eventuallythere's no doubt in my mind about that. But it may take a long time.”

Stravol grinned ruefully. "I expected no more. In a way, I think the whole project in crazy. But I'm in it right out to the end, all the same.”

Shar and Lavon grinned back. All of them had the fever, and Lavon suspected that their whole enclosed universe would share it with them before long. He said:

"Then let's not waste a minute. There's still a huge mass of detail to be worked out, and after that, all the hard work will just have begun. Let's get moving!”

The five men arose and looked at each other. Their expres- sions varied, but in all their eyes there was in addition the same mixture of awe and ambition: the composite face of the shipwright and of the astronaut.

Then they went out, severally, to begin their voyages.

It was two winter sleeps after Lavon's disastrous climb be- yond the sky that all work on the spaceship stopped. By then, Lavon knew that he had hardened and weathered into that temporarily ageless. state a man enters after he has just reached his prime; and he knew also that there were wrinkles engraved on his brow, to Stay and to deepen.

"Old" Shar, too, had changed, his features losing some of their delicacy as 'he came into his maturity. Though the wedge~ shaped bony structure of his face would give him a withdrawn and poetic look for as long as he lived, participation in 'the plan had given his expression a kind of executive overlay, which at best made it assume a mask-like rigidity, and at worst coarsened it somehow.

Yet despite the bleeding away of the years, the spaceship was still only a hulk. It lay upon a platform built above the tumbled boulders of the sandbar which stretched out from one wall of the world. It was an immense hull of pegged wood, broken by regularly spaced gaps through which the raw beams of its skeleton could be seen.

Work upon it had progressed fairly rapidly at first, for it was not hard to visualize what kind of vehicle would be needed to crawl through empty space without losing its water; Than and his colleagues had done that job well. It had been recognized, too, that the sheer size of the machine would en- force a long period of construction, perhaps as long as two full seasons; but neither Shar and his assistants nor Lavon had anticipated any serious snag.

For that matter, part of the vehicle's apparent incomplete- ness was an illusion. About a third of its fittings were to con- sist of living creatures, which could not be expected to install themselves in the vessel much before the actual takeoff.

Yet time and time again, work on the ship had to be halted for long periods. Several times whole sections needed to be ripped out, as it became more and more evident that hardly a single normal, understandable concept could be applied to the problem of space travel.

The lack of the history plate, which the Para steadfastly refused to deliver up, was a double handicap. Immediately upon its loss, Shar had set himself to reproduce it from mem- ory; but unlike the more religious of his ancestors, he had never regarded it as holy writ, and hence had never set him- self to memorizing it word by word. Even before the theft, he had accumulated a set of variant translations of passages pre- senting specific experimental problems, which were stored in his library, carved in wood. Most of these translations, how- ever, tended to contradict each other, and none of them re- lated to spaceship construction, upon which the original had been vague in any case.

No duplicates of the cryptic characters of the original had ever been made, for the simple reason that there was nothing in the sunken universe capable of destroying the originals, nor of duplicatihg their apparently changeless permanence.

Shar remarked too late that through simple caution they should have made a number of verbatim temporary records but after generations of green-gold peace, simple caution no longer covers preparation against catastrophe. (Nor, for that matter, does a culture which has to dig each letter of its simple alphabet into pulpy water-logged wood with a flake of stonewort encourage the keeping of records in triplicate.) As a result, Shar's imperfect memory of the contents of the history plate, plus the constant and miUenial doubt as to the accuracy of the various translations, proved finally to be the worst obstacle to progress on the spaceship itself.

"Men must paddle before they can swim," Lavon observed belatedly, and Shar was forced to agree with him.

Obviously, whatever the ancients had known about space- ship construction, very little of that knowledge was usable to a people still trying to build its first spaceship from scratch. In retrospect, it was not surprising that the great hulk rested in- complete upon its platform above the sand boulders, exuding a musty odor of wood steadily losing its strength, two genera- tions after its flat bottom had been laid down.

The fat-faced young man who headed the strike delega- tion to Shar's chambers was Phil XX, a man two generations younger than Shar, four younger than Lavon. There were crow's-feet at the comers of his eyes, which made him look both like a querulous old man and like an infant spoiled in the spore. ‘

"We're calling a halt to this crazy project," he said bluntly.

"We've slaved away our youth on it, but now that we're our own masters, it's over, that's all. It's over.”

"Nobody's compelled you," Lavon said angrily.

"Society does-, our parents do," a gaunt member of the del- egation said. "But now we're going to start living in the real world. Everybody these days knows that there's no other world but this one. You oldsters can hang on to your super- stitions if you like. We don't intend to.”

Baffled, Lavon looked over at Shar. The scientist smiled and said, "Let them go, Lavon. We have no use for the faint- hearted.”

The fat-faced young man flushed. "You can't insult us into going back to work. We're through. Build your own ship to no place!”

"All' right," Lavon said evenly. "Go on, beat it. Don't stand around here orating about it. You've made your decisions and we're not interested in your self-justifications. Goodbye.”

The fat-faced young man evidently still had quite a bit of heroism to dramatize which Lavon's dismissal had short-cir- cuited. An examination of Lavon's stony face, however, seemed to convince him that he had to take his victory as he found it. He and the delegation trailed ingloriously out the archway.

"Now what?" Lavon asked when they had gone. "I must admit, Shar, that I would have tried to persuade them. We do need the workers, after all.”

"Not as much as they need us," Shar said tranquilly. "I know all those young men. I think they'll be astonished at the runty crops their fields will produce next season, after they have to breed them without my advice. Now, how many volunteers have you got for the crew of the ship?”

"Hundreds. Every youngster of the generation after Phil's wants to go along. Phil's wrong about the segment of the pop- ulace, at least. The project catches the imagination of the very young.”

"Did you give them any encouragement?”

"Sure," Lavon said. "I told them we'd call on them if they were chosen. But you can't take that seriously! We'd do badly to displace our picked group of specialists with youths who have enthusiasm and nothing else.”

"That's not what I had in mind, Lavon. Didn't I see a Noc in these chambers somewhere? Oh, there he is, asleep in the dome. Noc!”

The creature stirred its tentacle lazily.

"Noc, I've a message," Shar called. "The Protos are to tell all men that those who wish to go to the next world with the spaceship must come to the staging area right away. Say that we can't promise to take everyone, but that only those who help us to build the ship will be considered at all.”

The Noc curled its tentacle again, and appeared to go back to sleep.

Lavon turned from the arrangement of speaking-tube mega- phones which was his control board and looked at Para.

"One last try," he said. "Will you give us back the history plate?”

"No, Lavon. We have never denied you anything before.

But this we must.”

"You're going with us, though, Para. Unless you give. us back the knowledge we need, you'll lose your life if we lose ours." ‘

"What is one Para?" the creature said. "We are all alike.

This cell will die; but the Protos need to know how you fare on this journey. We believe you should make it without the plate, for in no other way can we assess the real importance of the plate.”

"Then you admit you still have it. What if you can't com- municate with your fellows once we're out in space? How do you know that water isn't essential to your telepathy?”

The Proto was silent. Lavon stared at it a moment, then turned deliberately back to the speaking tubes. "Everyone hang on," he said. He felt shaky. "We're about to start. Stra- vol, is the ship sealed?”

"As far as I can tell, Lavon.”

Lavon shifted to another megaphone. He took a deep breath. Already the water seemed stifling, although the ship hadn't moved.

"Ready with one-quarter power. . . . One, two, three, go.”

The whole ship jerked and settled back into place again.

The raphe diatoms along the under hull settled into their niches, their jelly treads turning against broad endless belts of crude caddis-worm leather. Wooden gears creaked, step- ping up the slow power of the creatures, transmitting it to the sixteen axles of the ship's wheels.

The ship rocked and began to roll slowly along the sand bar. Lavon looked tensely through the mica port. The world flowed painfully past him. The ship canted and began to climb the slope. Behind him, he could feel the electric silence of Shar, Para, and the two alternate pilots. Than and Stravol, as if their gaze were stabbing directly through his body and on out the port. The world looked different, now that he was leaving it. How had he missed all this beauty before?

The slapping of the endless belts and the squeaking and groaning of the gears and axles grew louder as the slope steep- ened. The ship continued to climb, lurching. Around it, squad- rons of men and Protos dipped and wheeled, escorting it to- ward the sky.

Gradually the sky lowered and pressed down toward the top of the ship.

"A little more work from your diatoms, Tanol," Lavon said. "Boulder ahead." The ship swung ponderously. "All right, slow them up again. Give us a shove from your side, Tolno, that's too muchthere, that's it. Back to normal; you're still turning us I Tanol, give us one burst to line us up again. Good. All right, steady drive on all sides. It shouldn't be long now.”

"How can you think in webs like that?" the Para won- dered behind him.

"I just do, that's all. It's the way men think. Overseers, a little more thrust now; the grade's getting steeper.”

The gears groaned. The ship nosed up. The sky brightened in Lavon's face. Despite himself, he began to be frightened.

His lungs seemed to burn, and in his mind he felt his long fall through nothingness toward the chill slap of the water as if he were experiencing it for the first time. His skin itched and burned. Ctould he go up there again? Up there into the burning void, the great gasping agony where no life should go?

The sand bar began to level out and the going became a little easier. Up here, the sky was so close that the lumbering motion of the huge ship disturbed it. Shadows of wavelets ran across the sand. Silently, the thick-barreled bands of blue-green algae drank in the light and converted it to oxy- gen, writhing in their slow mindless dance just under the long mica skylight which ran along the spine of the ship. In the hold, beneath the latticed corridor and cabin floors, whirring Vortae kept the ship's water in motion, fueling them- selves upon drifting organic particles.

One by one, the figures wheeling outside about the ship waved arms or cilia and fell back, coasting down the slope of th? sand bar toward the familiar world, dwindling and disappearing. There was at last only one single Euglena, half- plant cousin of the Protos, forging along beside the space- ship into the marshes of the shallows. It loved the light, but finally it, too, was driven away into deeper, cooler waters, its single whiplike tentacle undulating placidly as it went. It was not very bright, but Lavon felt deserted when it left.

Where they were going, though, none could follow.

Now the sky was nothing but a thin, resistant skin of water coating the top of the ship. The vessel slowed, and when Lavon called for more power, it began to dig itself in among the sandgrains and boulders.

"That's not going to work," Shar said tensely. "I think we'd better step down the gear-ratio, Lavon, so you can apply stress more slowly.”

"All right," Lavon agreed. "Full stop, everybody. Shar, will you supervise gear-changing, please?”

Insane brilliance of empty space looked Lavon full in the face just beyond his big mica bull'seye. It was maddening to be forced to stop here upon the threshold of infinity; and it was dangerous, too. Lavon could feel building in him the old fear of the outside. A few moments more of inaction, he knew with a gathering coldness in his belly, and he would 'be un- able to go through with it.

Surely, he thought, there must be a better way to change gear-ratios than the traditional one, which involved disman- tling almost the entire gear-box. Why couldn't a number of gears of different sizes be carried on the same shaft, not nec- essarily all in action at once, but awaiting use simply by shov- ing the axle back and forth longitudinally in its sockets? It would still be clumsy, but it could be worked on orders from the bridge and would not involve shutting down the entire machineand throwing the new pilot into a blue-green funk.

Shar came lunging up through the trap and swam himself to a stop.

"All set," he said. "The big reduction gears aren't taking the strain too well, though.”

"Splintering?”

"Yes. I'd go it slow at first.”

Lavon nodded mutely. Without allowing himself to stop, even for a moment, to consider the consequences of his words, he called: "Half power." , The ship hunched itself down again and began to move, very slowly indeed, but more smoothly than before. Over- head, the sky thinned to complete transparency. The great light came blasting in. Behind Lavon there was an uneasy stir.

The whiteness grew at the front ports.

Again the ship slowed, straining against the blinding bar- rier. Lavon swallowed and called for more power. The ship groaned like something about to die. It was now almost at a standstill.

"More power," Lavon ground out.

Once more, with infinite slowness, the ship began to move.

Gently, it tilted upward.

Then it lunged forward and every board and beam in it began to squall.

"Lavoni Lavon!”

Lavon started sharply at the shout. The voice was coming at him from one of the megaphones, the one marked for the port at the rear of the ship.

"Lavoni”

"What is it? Stop your damn yelling.”

"I can see the top of the skyl From the other side, from the top side! It's like a big flat sheet of metal. We're going away from. it. We're above the sky, Lavon, we're above the sky!”

Another violent start swung Lavon around toward the for- ward port. On the outside of the mica, the water was evap- orating with shocking swiftness, taking with it strange distor- tions and patterns made of rainbows.

Lavon saw space.

It was at first like a deserted and cruelly dry version of the Bottom. There were enormous boulders, great cliffs, tumbled, split, riven, jagged rocks going up and away in all directions, as if scattered at random by some giant.

But it had a sky of its owna deep blue dome so far away that he could not believe in, let alone estimate, what its dis- tance might be. And in this dome was a ball of reddish-white fire that seared his eyeballs.

The wilderness of rock was still a long way away from the ship, which now seemed to be resting upon a level, glistening plain. Beneath the surface-shine, the plain seemed to be made of sand, nothing but familiar sand, the same substance which had heaped up to form a bar in Lavon's universe, the bar along which the ship had climbed. But the glassy, colorful skin over it Suddenly Lavon became conscious of another shout from the megaphone banks. He shook his head savagely and said, "What is it now?”

"Lavon, this is Tol. What have you gotten us into? The belts are locked. The diatoms can't move them. They aren't faking, either; we've rapped them hard enough to make them think we were trying to break their shells, but they still can't give us more power.”

"Leave them alone," Lavon snapped. "They can't fake; they haven't enough intelligence. If they say they can't give you more power, they can't.”

"Well, then, you get us out of it.”

Shar came forward to Lavon's elbow. "We're on a spac&- water interface, where the surface tension is very high," he said softly. "If you order the wheels pulled up now, I think we'll make better progress for a while on the belly tread.”

"Good enough," Lavon said with relief. "Hello below haul up the wheels.”

"For a long while," Shar said, "I couldn't understand the reference of thi history plate to 'retractable landing gear,' but it finally occurred to me that the tension along a space-mud interface would hold any large object pretty tightly. That's why I insisted on our building the ship so that we could lift the wheels.”

"Evidently the ancients knew their business after all, Shar.”

Quite a few minutes laterfor shifting power to the belly treads involved another setting of the gear boxthe ship was crawling along the shore toward the tumbled roc5. Anx- iously, Lavon scanned the jagged, threatening wall for a break. There was a sort of rivulet off toward the teft which might offer a route, though a dubious one, to the next world.

After some thought, Lavon ordered his ship turned toward it.

"Do you suppose that thing in the sky is a 'star'?" he asked.

"But there were supposed to be lots of them. Only one is up .thereand one's plenty for my taste.”

"I don't know," Shar admitted. "But I'm beginning to get a picture of the way the universe is made, I think. Evidefttly our world is a sort of cup in the Bottom of this huge one.

This one has a sky of its own; perhaps it, too, is only a cup in the Bottom of a still huger world, and so on and on with- out end. It's a hard concept to grasp, I'll admit. Maybe it would be more sensible to assume that all the worlds are cups in this one common surface, and that the great light shines on them all impartially.”

"Then what makes it go out every night, and dim even in the day during winter?" Lavon demanded.

"Perhaps it travels in circles, over first one world, then an- other. How could I know yet?”

"Well, if you're right, it means that all we have to do is crawl along here for a while, until we hit the top of the sky' of another world," Lavon said. "Then we dive in. Somehow it seems too simple, after all our preparations.”

Shar chuckled, but the sound did not suggest that he had discovered anything funny. "Simple? Have you noticed the temperature yet?”

Lavon had noticed it, just beneath the surface of aware- ness, but at Shar's remark he realized that he was gradually being stifled. The oxygen content of the water, luckily, had not dropped, but the temperature suggested the shallows in the last and worst part of autumn. It was like trying to breathe soup.

"Than, give us more action from the Vortae," Lavon said.

"This is going to be unbearable unless we get more circula- tion.”

There was a reply from Than, but it came to Lavon's ears only as a mumble. It was all he could do now to keep his at- tention on the business of steering the ship.

The cut or defile in the scattered razor-edged rocks was a little closer, but there still seemed to be many miles of rough desert to cross. After a while, the ship settled into a steady, painfully slow crawling, with less pitching and jerking than before, but also with less progress. Under it, there was now a sliding, grinding sound, rasping against the hull of the ship itself, as if it were treadmilling over some coarse lubricant the particles of which were each as big as a man's head.

Finally Shar said, "Lavon, we'll have to stop again. The sand this far up is dry, and we're .wasting energy using the tread.”

"Are you sure we can take it?" Lavon asked, gasping for breath. "At least we are moving. If we stop to lower the wheels and change gears again, we'll boil.”

"We'll boil if we don't," Shar said calmly. "Some of our algae are dead already and the rest are withering. That's a pretty good sign that we can't take much more. I don't think we'll make it into the shadows, unless we do change over and put on some speed.”

There was a gulping sound from one of the mechanics. "We ought to turn back," he said raggedly. "We were never meant to be outhere in the first place. We were made for the water, not for this hell.”

"We'll stop," Lavon said, "but we're not turning back. That's final." - The words made a brave sound, but the man had upset Lavon more than he dared to admit, even to himself. "Shar,”

he said, "make it fast, will you?”

The scientist nodded and dived below.

The minutes stretched out. The great red-gold globe in the sky blazed and blazed. It had moved down the sky, far down, so that the light was pouring into the ship directly in Lavon's face, illuminating every floating particle, its rays like long milky streamers. The currents of water passing Lavon's cheek were almost hot.

How could they dare go directly forward into that inferno?

The land directly under the "star" must be even hotter than it was here.

"Lavon! Look at Paral”

Lavon forced himself to turn and look at his Proto ally.

The great slipper had settled to the deck, where it was lying with only a feeble pulsation of its cilia. Inside, its vacuoles were beginning to swell, to become bloated, pear-shaped bubbles, crowding the granulated cytoplasm, pressing upon the dark nuclei.

"Is . . . is he dying?”

"This cell is dying," Para said, as coldly as always. "But go ongo on. There is much to learn, and you may live, even though we do not. Go on.”

"You'refor us now?" Lavon whispered.

"We have alway been for you. Push your folly to the utter- most. We will benefit in the end, and so will Man.”

The whisper died away. Lavon called the creature again, but it did not respond.

There was a wooden clashing from below, and then Shar's voice came tinnily from one of the megaphones. "Lavon, go aheadi The diatoms are dying, too, and then we'll be without power. Make it as quickly and directly as you can.”

Grimly, Lavon leaned forward. "The 'star' is directly over the land we're approaching.”

"It is? It may go lower still and the shadows will get longer.

That may be our only hope.”

Lavon had not thought of that. He rasped into the banked megaphones. Once more, the ship began to move, a little faster now, but seemingly still at a crawl. The thirty-two wheels rumbled.

It got hotter.

Steadily, with a perceptible motion, the "star" sank in Lavon's face. -Suddenly a new terror struck him. Suppose it should continue to go down until it Was gone entirely? Blast- ing though it was now, it was the only source of heat. Would not space become bitter cold on the instantand the ship an expanding, bursting block of ice?

The shadows lengthened menacingly, stretching across the desert toward the forward-rolling vessel. There was no talking in the cabin, just the sound of ragged breathing and the creaking of the machinery.

Then the jagged horizon seemed to rush upon them. Stony teeth cut into the lower rim of the ball of fire, devoured it swiftly. It was gone.

They were in the lee of the cliffs. Lavon ordered the ship turned to parallel the rock-line; it responded heavily, slug- gishly. Far above, the sky deepened steadily, from blue to indigo.

Shar came silently up through the trap and stood beside Lavon, studying that deepening color and the lengthening of the shadows down the beach toward their own world. He said nothing, but Lavon was sure that the same chilling thought was in his mind.

"Lavon.”

Lavon jumped. Shar's voice had iron in it. "Yes?”

"We'll have to keep moving. We must make the next world, wherever it is, very shortly.”

"How can we dare move when we can't see where we're going? Why not sleep it overif the cold will let us?”

"It will let us," Shar said. "It can't get dangerously cold up here. If it did, the skyor what we used to think of as the skywould have frozen over every night, even in summer.

But what I'm thinking about is the water. The plants will go to sleep now. In our world that wouldn't matter; the supply of oxygen there is enough to last through the night. But in this confined space, with so many creatures in it and no supply of fresh water, we will probably smother.”

Shar seemed hardly to be involved at all, but spoke rather with the voice of implacable physical laws.

"Furthermore," he said, staring unseeingly out at the raw landscape, "the diatoms are plants, too. In other words, we must stay on the move for as long as we have oxygen and powerand pray that we make it." .

"Shar, we had quite a few Protos on board this ship once.

And Para there isn't quite dead yet. If he were, the cabin would be intolerable. "The ship is nearly sterile of bacteria, because all the protos have been eating them as a matter of course and there's no outside supply of them, either. But still and all there would have been some decay.”

Shar bent and tested the pellicle of the motionless Para with a probing finger. "You're right, he's still alive. What does that prove?”

"The Vortae are also alive; I can feel the water circulating.

Which proves that it wasn't the heat that hurt Para. it was the light. Remember how badly my skin was affected after I climbed beyond the sky? Undiluted starlight is deadly. We should add that to the information from the plate.”

"I still don't get the point.”

"It's this: We've got three or four Noc down below. They were shielded from the light, and so must be still alive. If we concentrate them in the diatom galleys, the dumb diatoms will think it's still daylight and will go on working. Or we can con- centrate them up along the spine-of the ship, and keep the algae putting out oxygen. So the question is: Which do we need more, oxygen or power? Or can we split the difference?”

Shar actually grinned. "A brilliant piece of thinking. We may make a Shar out of you some day, Lavon. No, I'd say that we can't split the difference. Noc's light isn't intense enough to keep the plants making oxygen; I tried it once, and the oxygen production was too tiny to matter. Evidently the plants use the light for energy. So we'll have to settle for the diatoms for motive power.”

"All right. Set it up that way, Shar.”

Lavon brought the vessel away from the rocky lee of the cliff, out onto the smoother sand. All trace of direct light was now gone, although there was still a soft, general glow on the sky. , "Now then," Shar said thoughtfully, "I would guess that there's water over there in the canyon, if we can reach it. I'll go below again and arrange”

Lavon gasped.

"What's the matter?”

Silently, Lavon pointed, his heart pounding.

The entire dome of indigo above them was spangled with ' tiny, incredibly brilliant lights. There were hundreds of them, and more and more were becoming visible as the darkness deepened. And far away, over the ultimate edge of the rocks, was a dim red globe, crescented wigh ghostly silver. Near the zenith was another such body, much smaller, and silvered all over...

Under the two moons of Hydrot, and under the eternal stars, the two-inch wooden spaceship and its microscopic cargo toiled down the slope toward the drying little rivulet.

The ship rested on the Bottom of the canyon for the rest of the night. The great square doors were unsealed and thrown open to admit the raw, irradiated, life-giving water from out- sideand the wriggling bacteria which were fresh food.

No other creatures approached them, either out of curi- osity or for hunting, while they slept, although Lavon had posted guards at the doors just in case. Evidently, even up here on the very floor of space, highly organized creatures were quiescent at night.

But when the first flush of light filtered through the water, trouble threatened.

First of all, there was the bug-eyed monster. The thing was green and had two snapping claws, either one of which could have broken the ship in two like a spirogyra strand. Its eyes were black and globular, on the ends of short columns, and its long feelers were thicker through than a plant bole. It passed in a kicking fury of motion, however, never noticing the ship at all.

"Is thata sample of the kind of life they have here?" La- von whispered. "Does it all run as big as that?" Nobody an- swered, for the very good reason that nobody knew.

After a while, Lavon risked moving the ship forward against the current, which was slow but heavy. Enormous writhing worms whipped past them. One struck the hull a heavy blow, then thrashed on obliviously.

"They don't notice us," Shar said. "We're too small. Lavon, the ancients warned us of the immensity of space, but even when you see it, it's impossible to grasp. And all those stars can they mean what I think they mean? It's beyond thought, beyond belief!”

"The Bottom's sloping," Lavon said, looking ahead intently.

"The walls of the canyon are retreating, and the water's be- coming rather silty. Let the stars wait, Shar; we're coming toward the entrance of our new world.”

Shar subsided moodily. His vision of space apparently had disturbed him, perhaps seriously. He took little notice of the great thing that was happening, but instead huddled worriedly over his own expanding speculations. Lavon felt the old gap between their minds widening once more.

Now the Bottom was tilting upward again. Lavon had no experience with delta-formation, for no rivulets left his own world, and the phenomenon worried him. But his worries were swept away in wonder as the ship topped the rise and nosed over.

Ahead, the Bottom sloped away again, indefinitely, into glimmering depths. A proper sky was over them once more, and Lavon could see small rafts of plankton floating placidly beneath it. Almost at once, too, he saw several of the smaller kinds of Protos, a few of which were already approaching the ship Then the girl came darting out of the depths, her features blurred and distorted with distance and terror. At first she did not seem to see the ship at all. She came twisting and turning lithely through the water, obviously hoping only to throw herself over the mound of the delta and into the sav- age streamlet beyond.

Lavon was stunned. Not that there were men herehe had hoped for that, had even known somehow that men were everywhere in the universebut at the girl's single-minded flight toward suicide.

"What”

Then a dim buzzing began to grow in his ears, and he un- derstood.

"Sharl Than! Stravoll" he bawled. "Break out crossbows and spears! Knock out all the windows!" He lifted a foot and kicked through the port in front of him. Someone thrust a crossbow into his hand.

"What?" Shar blurted. "What's the matter? What's happen- ing?”

"Eaters!”

The cry went through the ship like .a galvanic shock. The rotifers back in Lavon's own world were virtually extinct, but everyone knew 'thoroughly the grim history of the long battle man and Proto had waged against them.

The girl spotted the ship suddenly and paused, obviously stricken with despair at the sight of this new monster. She drifted with her own momentum, her eyes alternately fixed upon the ship and jerking back over her shoulder, toward where the buzzing snarled louder and louder in the dimness.

"Don't stop!" Lavon shouted. "This way, this way! We're friends! We'll help!”

Three great semi-transparent trumpets of smooth flesh bored over the rise, the many thick cilia of their coronas whirring greedily. Dicrans, arrogant in their flexible armor, quarrel- ing thickly among themselves as they moved, with the few blurred, pre-symbolic noises which made up their own lan- guage. ‘

Carefully, Lavon wound the crossbow, brought it to his shoulder, and fired. The bolt sang away through the water. It lost momentum rapidly, and was caught by a stray current which brought it closer to the girl than to the Eater at which Lavon had aimed.

He bit his lip, lowered the weapon, wound it up again. It did not pay to underestimate the range; he would have to wait.

Another bolt, cutting through the water from a side port, made him issue orders to cease firing "until," he added, "you can see their eyespots.”

The irruption of the rotifers decided the girl. The motion- less wooden monster was of course strange to her, but it had not yet menaced herand she must have known what it would be like to have three Dicrans over her, each trying to grab from the others the largest share. She threw herself to- wards the bull'seye port. The three Eaters screamed with fury and greed and bored in after her.

She probably would not have made it, had not the dull vi- sion of the lead Dicran made out the wooden shape of the ship at the last instant. The Dicran backed off, buzzing, and the other two sheered away to avoid colliding with her. After that they had another argument, though they could hardly have formulated what it was that they were fighting .about; they were incapable of exchanging any thought much more complicated than the equivalent of "Yaah," "Drop dead,”

and "You're another.”

While they were still snarling at each other, Lavon pierced the nearest one aU the way through with an arablast bolt.

The surviving two were at once involved in a lethal battle over the remains.

"Than, take a party out and spear me those two Eaters while they're still fighting," Lavon ordered. "Don't forget to destroy their eggs, too. I can see that this world needs a little taming.”

The girl shot through the port and brought up against the far wall of the cabin, flailing in terror. Lavon tried to approach her, but from somewhere she produced a flake of stonewort chipped to a nasty point. Since she was naked, it was hard to tell where she had been hiding it, but she obviously knew how to use it, and meant to. Lavon retreated and sat down on the stool before his control board, waiting while she took in the cabin, Lavon, Shar, the other pilots, the senescent Para.

At last she said: "Areyouthe godsfrom beyond the sky?”

"We're from beyond the sky, all right," Lavon said. "But we're not gods. We're human beings, just like you. Are there many humans here?”

The girl seemed to assess the situation very rapidly, savage though she was. Lavon had the odd and impossible impression that he should recognize her: a tall, deceptively relaxed, tawny woman, not after all quite like this one . . . a woman from another world, to be sure, but still . . .

She tucked the knife back into her bright, matted hairaha, Lavon thought confusedly, there's a trick I may need to re- memberand shook her head.

"We are few. The Eaters are everywhere. Soon they will have the last of us.”

Her fatalism was so complete that she actually did not seem to care.

"And you've never cooperated against them? Or asked the Protos to help?”

"The Protos?" She shrugged. "They are as helpless as we are against the Eaters, most of them. We have no weapons that kill at a distance, like yours. And it's too late now for such weapons to do any good. We axe too few, the Eaters too many.”

Labon shook his head emphatically. "You've had one weapon that counts, all along. Against it, numbers mean noth- ing. We'll show you how we've used it. You may be able to use it even better than we did, once you've given it a try.”

The girl shrugged again. "We dreamed of such a weapon, but never found it Are you telling the truth? What is the weapon?”

"Brains, of course," Lavon said. "Not just one brain, but a lot of them. Working together. Cooperation.”

"Lavon speaks the truth," a weak voice said from the deck.

The Para stirred feebly. The girl watched it with wide eyes.

The sound of the Para using human speech seemed to impress her more than the ship itself, or anything else that it con- tained.

"The Eaters can be conquered," the thin, burring voice said. "The Protos will help, as they helped in the world from which we came. The Protos fought this flight through space, and deprived Man of his records; but Man made the trip with- out the records. The Protos will never oppose Man again. We have already spoken to the Protos of this world, and have told them that what Man can dream, Man can do. Whether the Protos will it or not.

"Sharyour metal record is with you. It was hidden in the ship. My brothers will lead you to it.

"This organism dies now. It dies in confidence of knowl- edge, as an intelligent creature dies. Man has taught us this.

There is nothing. That knowledge. Cannot do. With it . . .

men . . ."have crossed . . . have crossed space . . .”

The voice whispered away. The shining slipper did not change, but something about it was gone. Lavon looked at the girl; their eyes met. He felt an unaccountable Warmth.

"We have crossed space," Lavon repeated softly.

Shar's voice came to him across a great distance. The young-old man was whispering: "Buthave we?”

Lavon was looking at the girl. He had no answer for Shar's question. It did not seem to be important.