"Every proto has heard it and agrees with it. We have been afraid of these metal plates for a long time, afraid that men would learn to understand them and to follow what they say to some secret place, leaving the protos behind. Now we are not afraid."
"There wasn't anything to be afraid of," Lavon said indulgently.
"No Lavon before you had said so," Para said. "We are glad. We will throw the plates away."
With that, the shining creature swooped toward the embrasure. With it, it bore away the remaining plates, which had been resting under it on the table-top, suspended delicately in the curved tips of its supple cilia. With a cry, Shar plunged through the water toward the opening.
"Stop, Para!"
But Para was already gone, so swiftly that he had not even heard the call. Shar twisted his body and brought up on one shoulder against the tower wall. He said nothing. His face was enough. Lavon could not look at it for more than an instant.
The shadows of the two men moved slowly along the uneven cobbled floor. The Noc descended toward them from the vault, its single thick jentacle stirring the water, its internal light flaring and fading irregularly. It, too, drifted through the window after its cousin, and sank slowly away toward the bottom. Gently its living glow dimmed, flickered, winked out.
II
For many days, Lavon was able to avoid thinking much about the loss. There was always a great deal of work to be done. Maintenance of the Castles, which had been built by the now-extinct Eaters, was a never-ending task. The thousand dichotomously branching wings tended to crumble, especially at their bases where they sprouted from each other, and no Shar had yet come forward with a mortar as good as the rotifer-spittle which had once held the together. In addition, the breaking through of windows and the construe tion of chambers in the early days had been haphazard and often un sound. The instinctive architecture of the rotifers, after all, had not been meant to meet the needs of human occupants.
And then there were the crops. Men no longer fed precariously upon passing bacteria; now there were the drifting mats of specific water- fungi, rich and nourishing, which had been bred by five generations of Shars. These had to be tended constantly to keep the strains pure, and to keep the older and less intelligent species of the protos from grazing on them. In this latter task, to be sure, the more intricate and farseeing proto types cooperated, but men were needed to supervise.
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 puzzlement of the protos. The blurred and simple-minded speech of the gorgeously engraved plants had brought them into the category of pets— a 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 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 a 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 forge that moment when the last clues to Man's origin and destination ha been seized and borne away into dim space.
It might be possible to ask Para for the return of the plates, explain that a mistake had been made. The protos were creatures of implacable logic, but they respected Man, were used to illogic in Man, and might reverse their decision if pressed—
We are sorry. The plates were carried over the bar and released the gulf. We will have the bottom there searched, but...
With a sick feeling he could not repress, Lavon knew that when rotos 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 conscience, Lavon was convinced that the plates were well lost. What had they ever done for man, except to provide Shars 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 ever had come from the plates.
There had never been anything in the plates 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 experimental 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 original thought, was a gift as well as a limitation. It allowed them to see and feel things at all times as they were—not as they hoped they might be, for they had no ability to hope, either.
"La-von! Laavah-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 splitting free the glutinous tetrads of the algae.
"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 °f the finest-drawn gold. The great light which lived above the sky during the day, brightening or dimming according to some pattern no ahar ever had fathomed, was blooming again.
Few men, caught in the warm glow of that light, could resist looking up at it—
especially 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. bobbling action, and a reflection 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, the invisible division between the colder waters of the bottom and the warm, light waters of the sky. During the height of the warm weather, the thermocline was definite enough a division as to make for good sledding and for chilly passage. A real interface formed between the cold, denser bottom waters and th warm reaches above, and maintained itself almost for the whole of the warm season.
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 waning as it chose, seemed to be one of its properties
Toward the end of the season, the water gradually grew colder and more difficult to breathe, while at the same time the light became duller and stayed for shorter periods between darknesses. Slow currents started to move. The high waters turned chill and began 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.
Then the protos encysted; the bacteria, even most of the plants and, not long afterward, men, too, curled up in their oil-filled amber shells. The world died until the first tentative current of warm water broke the winter silence.
"La-von!"
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 invulnerable —and when some especially hard blow or edge did penetrate them, they broke into smaller bubbles which nothing could touch, and fled toward the sky, leaving behind 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 penetrate a bubble. The surface tension was too strong. As strong as Shar's metal plates. As strong as the top of the sky.
As strong as the top of the sky. And above that—once the top was broken—a 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 infant cosmology include any provisions for Bottoms for the worlds.
And yet some of the local creatures did burrow into the bottom, quite , epjy; seeking something in those depths which was beyond the reach f Man. Even the surface of the ooze, in high summer, crawled with tiny creatures for which mud was a natural medium. Man, too, passed freely between the two countries of water which were divided by the thermocline, though many of the creatures with which he lived could not pass that line at all, once it had established itself.
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 be broken showed that the surface skin that formed between water and gas wasn't completely invulnerable. 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 the difficulty. Here at his back, for instance, was a plant which gave every appearance of continuing beyond the sky: its uppermost fronds broke off and were bent back only by a trick of reflection.
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 imbedded in the perfect mirror. But some were simply chopped off, like the one which sheltered him now.
Perhaps that was only an illusion, and instead it soared indefinitely into some other place—some place where men might once have been born, and might still live ...
The 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 obliviously upon the clustered sheaves 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? Lavon!"
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. Then he began to climb again, breathless.
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 enormous weight.
It was fruitless. He might as well have tried to penetrate a cliff.