Arthur C Clarke - City And The Stars Read online

  Eight

  The image on the monitor screen faded as alvin raised his hands from the control panel and cleared the circuits. For a moment he sat quite motionless, looking into the blank rec-tangle that had occupied all his conscious mind for so many weeks. He had circumnavigated his world; across that screen had passed every square foot of the outer wall of diaspar. He knew the city better than any living man save perhaps iche-dron; and he knew now that there was no way through the walls. The feeling that possessed him was not mere despondency; be had never really expected that it would be as easy as this, that he would find what he sought at the first attempt. What was important was that he had eliminated one possibility. Now he must deal with the others. He rose to his feet and walked over to the image of the city which almost filled the chamber. It was hard not to think of it as an actual model, though he knew that in reality it was no more than an optical projection of the pattern in the memory cells he had been exploring. When he altered the monitor controls and set his viewpoint moving through dias-par, a spot of light would travel over the surface of this rep-lica, so that he could see exactly where he was going. It had been a useful guide in the early days, but he soon had grown so skillful at setting the co-ordinates that he had not needed this aid. The city lay spread out beneath him; he looked down upon it like a god. Yet he scarcely saw it as he considered, one by one, the steps he should now take. If all else failed, there was one solution to the problem. Diaspar might be held in a perpetual stasis by its eternity circuits frozen forever according to the pattern in the memory cells, but that pattern could itself be altered, and the city would then change with it. It would be possible to redesign a section of the outer wall so that it contained a doorw feed this pattern into the monitors, and let the city resh itself to the new conception. Alvin suspected that the large areas of the monitor control board whose purpose khedron had not explained to him concerned with such alterations. It would be useless to periment with them; controls that could alter the very structure of the city were firmly locked and could be operated only with the authority of the council and the approval the central computer. There was very little chance that council would grant him what he asked, even if he was prepared for decades or even centuries of patient pleading. This was not a prospect that appealed to him in the least. He turned his thoughts toward the sky. Sometimes he imagined, in fantasies which he was half-ashamed to recall that he had regained the freedom of the air which man h renounced so long ago. Once, he knew, the skies of earth ha been filled with strange shapes. Out of space the great ships had come, bearing unknown treasures, to berth at the legendary port of diaspar. But the port had been beyond the limits of the city; aeons ago it had been buried by the drifting sand he could dream that somewhere in the mazes of diaspar flying machine might still be hidden, but he did not really lieve it. Even in the days when small, personal flyers had bee in common use, it was most unlikely that they had ever be 1 allowed to operate inside the limits of the city. For a moment he lost himself in the old, familiar dream. He imagined that he was master of the sky, that the world lay spread out beneath him, inviting him to travel where hewilled. It was not the world of his own time that he saw, but the lost world of the dawn-a rich and living panorama of hills and lakes and forests. He felt a bitter envy of his unknown ancestors, who had flown with such freedom over the earth and who had let its beauty die. This mind-drugging reverie was useless; he tore himself back to the present and to the problem at hand. If the sky was unattainable and the way by land was barred, what remained? Once again he had come to the point when he needed help, when he could make no further progress by his own efforts he disliked admitting the fact, but was honest enough not deny it. Inevitably, his thoughts turned to khedron. Alvin had never been able to decide whether he liked the jester. He was very glad that they had met, and was grateful to khedron for the assistance and implicit sympathy he had given him on his quest. There was no one else in diaspar with whom he had so much in common, yet there was some element in the other's personality that jarred upon him. Perhap it was khedron's air of ironic detachment, which sometime gave alvin the impression that he was laughing secretly at all his efforts, even while he seemed to be doing his best to help. Because of this, as well as his own natural stubbornness and independence, alvin hesitated to approach the jester except as a last resort. They arranged to meet in a small, circular court not far from council hall. There were many such secluded spots in the city, perhaps only a few yards from some busy thoroughfare, yet completely cut off from it. Usually they could be reached only on foot after a rather roundabout walk; some-times, indeed, they were at the center of skillfully contrived mazes which enhanced their isolation. It was rather typical of khedron that he should have chosen such a place for a rendevous. The court was little more than fifty paces across, and was in reality located deep within the interior of some great building. Yet it appeared to have no definite physical limits, being bounded by a translucent blue-green material which glowed with a faint internal light. However, though there were no visible limits, the court had been so laid out that there was no danger of feeling lost in infinite space. Low walls, less than waist high and broken at intervals so that one could pass through them managed to give the impression of safe con-finement without which no one in diaspar could ever feel entirely happy. Khedron was examining one of these walls when alvin arrived. It was covered with an intricate mosaic of colored tiles, so fantastically involved that alvin did not even attempt to unravel it. "Look at this mosaic, alvin," said the jester. "Do you notice anything strange about it?" "no," confessed alvin after a brief examination. "I don't care for it-but there's nothing strange about that." khedron ran his fingers over the colored tiles. "You are not very observant," he said. "Look at these edges here-see how they become rounded and softened. This is something that one very seldom sees in diaspar, alvin. It is wear-the crumbling away of matter under the assault of time. I can remember when this pattern was new, only eighty thousand years ago, in my last lifetime. If i come back to this spot a dozen lives from now, these tiles will have been worn completely away." "i don't see anything very surprising about that," answered alvin. "There are other works of art in the city not good enough to be preserved in the memory circuits, but not bad enough to be destroyed outright. One day, i suppose, some other artist will come along and do a better job. And his work won't be allowed to wear out." "i knew the man who designed this wall," said khedron, his fingers still exploring the cracks in the mosaic. "Strange that i can remember that fact, when i don't recall the man himself. I could not have liked him, so i must have erased him from my mind." he gave a short laugh. "Perhaps i designed it myself, during one of my artistic phases, and was so annoyed when the city refused to make it eternal that i decided to forget the whole affair. There i knew that piece was coming loosel" he had managed to pull out a single flake of golden tile, and looked very pleased at this minor sabotage. He threw the fragment on the ground, adding, "now the maintenance robots will have to do something about it!" there was a lesson for him here, alvin knew. That strange instinct known as intuition, which seemed to follow short cuts not accessible to mere logic, told him that. He looked at the golden shard lying at his feet, trying to link it somehow to the problem that now dominated his mind.

  It was not hard to find the answer, once he realized that it existed. Khedron "i see what you are trying to tell me," he said to khedron. "There are objects in diaspar that aren't preserved in the memory circuits, so i could never find them through the monitors at council hall. If i was to go there and focus on this court, there would be no sign of the wall we're sitting on." "i think you might find the wall. But there would be no mosaic on it." "yes, i can see that," said arvin, too impatient now to bother about such hairsplitting. "And in the same way, parts of the city might exist that had never been preserved in the eternity circuits, but which hadn't yet worn away. Still, i don't really see how that helps me. I know that the outer wall exists-and that it has no openings in it." "perhaps the
re is no way out, answered khedron. "I can promise you nothing. But i think there is still a great deal that the monitors can teach us-if the central computer will let them. And it seems to have taken rather a liking to you. Arvin pondered over this remark on their way to council hall. Until now, he had assumed that it was entirely through khedron's influence that he had been able to gain access to the monitors. It had not occurred to him that it might be through some intrinsic quality of his own. Being a unique had many disadvantages; it was only right that it should have some compensations. The unchanging image of the city still dominated the chamber in which arvin had spent so many hours. He looked at it now with a new understanding; all that he saw here existed-but all of diaspar might not be mirrored. Yet, surely, any discordancies must be trivial, and, as far as he could see, undetectable. I attempted to do this many years ago," said khedron, as he sat down at the monitor desk, but the controls were locked against me. Perhaps they will obey me now." slowly, and then with mounting confidence as he regained of the wall we're sitting access to long-forgotten skills, khedron's fingertips moved over the control desk, resting for a moment at the nodal points in the sensitive grid buried in the panel before him. "I think that's correct," he said at last. "Anyway we'll soon see." the screen glowed into life, but instead of the picture that alvin had expected, there appeared a somewhat baffling message:

  Regression will commence as soon as you have set rate control

  "Foolish of me," muttered khedron. "I got everything else right and forgot the most important thing of all." his fingers now moved with a confident assurance over the board, and as the message faded from the screen he swung around in his seat so that he could look at the replica of the city. "Watch this, alvin," he said. "I think we are both going to learn something new about diaspar." arvin waited patiently, but nothing happened. The image of the city floated there before his eyes in all its familiar wonder and beauty-though he was conscious of neither now. He was about to ask khedron what he should look for when a sudden movement caught his attention, and he turned his head quickly to follow it. It had been no more than a half-glimpsed flash or flicker, and he was too late to see what had made it. Nothing had altered; diasnar was just as he had al-ways known it. Then he saw that khedron was watching him with a sardonic smile, so he looked again at the city. This time, the thing happened before his eyes. One of the buildings at the edge of the park suddenly vanished, and was replaced instantly by another of quite dif-ferent design. The transformation was so abrupt that had arvin been blinking he would have missed it. He stared in amazement at the subtly altered city, but even during the first shock of astonishment his mind was seeking for the answer. He remembered the words that had appeared on the monitor screen-regression will commence-and he knew at once what was happening. "That's, the city as it was thousands of years ago," he said to khedrn. "We're going back in time." "a picturesque but hardly accurate way of putting it," re-plied the jester. "What is actually happening is that the monitor is remembering the earlier versions of the city. When any modifications were made, the memory circuits were not simply emptied; the information in them was taken to subsidiary storage units, so that it could be recalled whenever needed. I have set the monitor to regress through those units at the rate of a thousand years a second. Already, we're looking at the diaspar of half a million years ago. We'll have to go much farther back than that to see any real changes-i'11 increase the rate." he turned back to the control board, and even as he did so, not one building but a whole block whipped out of exis­tence and was replaced by a large oval amphitheater. "Ali, the arena!" said khedron. "I can remember the fuss when we decided to get rid of that. It was hardly ever used, but a great many people felt sentimental about it." the monitor was now recalling its memories at a far higher rate; the image of diaspar was receding into the past at mil­lions of years a minute, and changes were occurring so rapid­ly that the eye could not keep up with them. Alvin noticed that the alterations to the city appeared to come in cycles; there would be a long period of stasis, then a whole rash of , rebuilding would break out, followed by another pause. It was almost as if diaspar were a living organism, which had to re­gain its strength after each explosion of growth. Through all these changes, the basic design of the city had not altered. Buildings came and went, but the pattern of streets seemed eternal, and the park remained as the green heart of. Diaspar. Alvin wondered how far back the monitor could go. Could it return to the founding of the city, and pass through the veil that sundered known history from the myths and leg­ends of the dawn? Already they had gone five hundred million years into the past. Outside the walls of diaspar, beyond the knowledge of the monitors, it would be a different earth. Perhaps there might be oceans and forests, even other cities which man had not yet deserted in the long retreat to his final home. The minutes drifted past, each minute an aeon in the little universe of the monitors. Soon, thought alvin, the earliest of all these stored memories must be reached and the regres­sion would end. But fascinating though this lesson was, he q did not see how it could help him to escape from the city as it was here and now. With a sudden, soundless implosion, diaspar contracted to a fraction of its former size. The park vanished; the boundary wall of linked, titanic towers instantly evaporated. This city was open to the world, for the radial roads stretched out to , the limits of the monitor image without obstruction. Here was diaspar as it had been before the great change came upon mankind. ~~ "We can go no farther," said khedron, pointing to the monitor screen. On it had appeared the words: regression concluded. "This must be the earliest version of the city that has been preserved in the memory cells. Before that, i doubt if the eternity circuits were used, and the buildings were al­lowed to wear out naturally." for a long time, alvin stared at this model of the ancient city. He thought of the traffic those roads had borne, as men came and went freely to all the corners of the world-and to other worlds as well. Those men were his ancestors; he felt a closer kinship to them than to the people who now shared his life. He wished that he could see them and share their thoughts, as they moved through the streets of that billion­year-remote diaspar. Yet those thoughts could not have been happy ones, for they must have been living then beneath the shadow of the invaders. In a few more centuries, they were to turn their faces from the glory they had won and build a wall against the universe: khedron ran the monitor backward and forward a dozen times through the brief period of history that had wrought the transformation. The change from a small open city to a much larger closed one had taken little more than a thousand years. In that time, the machines that had served diaspar so faithfully must have been designed and built, and the knowl­edge that would enable them to carry out their tasks had been fed into their memory circuits. Into the memory circuits, also, must have gone the essential patterns of all the men who were now alive, so that when the right impulse called them forth again they could be clothed in matter and would emerge re­born from the hall of creation. In some sense, alvin realized, he must have existed in that ancient world. It was possible, of course, that he was completely synthetic-that his entire per­sonality had been designed by artist-technicians who had worked with tools of inconceivable complexity toward some clearly envisaged goal. Yet he thought it more likely that he was a composite of men who had once lived and walked on earth. Very little of the old diaspar had remained when the new city was created; the park had obliterated it almost complete­ly. Even before the transformation, there had been a small, grass-covered clearing at the center of diaspar, surrounding the junction of all the radial streets. Afterward it had expanded tenfold, wiping out streets and buildings alike. The tomb of yarlan zey had been brought into existence at this time, re­placing a very large circular structure which had previously stood at the meeting point of all the streets. Alvin had never really believed the legends of the tomb's antiquity, but now it seemed that they were true. "I suppose," said alvin, struck by a sudden thought, "that we can explore this image, just as we explored the image of today's diaspar?" khedro
n's fingers flickered over the monitor control board, and the screen answered alvin's question. The long-vanished city began to expand before his eyes as his viewpoint moved along the curiously narrow streets. This memory of the dias­par that once had been was still as sharp and clear as the image of the city he lived in today. For a billion years, the informa­tion circuits had held it in ghostly pseudo-existence, waiting for the moment when someone should call it forth again. And it was not, thought alvin, merely a memory he was seeing now. It was something more complex than that-it was the memory of a memory. He did not know what he could learn from it, and whether it could help him in his quest. No matter; it was fascinating to look into the past and to see a world that had existed in the days when men still roamed among the stars. He pointed to the low, circular building that stood at the city's heart. "Let's start there," he told khedron. "That seems as good a place as any to begin." perhaps it was sheer luck; perhaps it was some ancient memory; perhaps it was elementary logic. It made no dif. Ference since he would have arrived at this spot sooner or later-this spot upon which all the radial streets of the city converged. It took him ten minutes to discover that they did not meet here for reasons of symmetry alone ten minutes to know that his long search had met its reward.

  Nine

  Alystra had found it very easy to follow alvin and khed­ron without their knowledge. They seemed in a great hurry­something which in itself was most unusual-and never looked back. It had been an amusing game to pursue them along the moving ways, hiding in the crowds yet always keeping them in sight. Toward the end their goal had been obvious; when they left the pattern of streets and went into the park, they could only be heading for the tomb of yarlan zey. The park con­tained no other buildings, and people in such eager haste as alvin and khedron would not be interested merely in enjoy­ing the scenery. Because there was no way of concealing herself on the last few hundred yards to the tomb, alystra waited until khedron and alvin had disappeared into the marbled gloom. Then, as soon as they were out of sight, she hurried up the grass-cov­ered slope. She felt fairly sure that she could hide behind one of the great pillars long enough to discover what alvin and khedron were doing; it did not matter if they detected her after that. The tomb consisted of two concentric rings of columns, enclosing a circular courtyard. Except in one sector, the col­umns screened off the interior completely, and alystra avoided approaching through this opening, but entered the tomb from the side. She cautiously negotiated the first ring of columns, saw that there was no one in sight, and tiptoed across to the second. Through the gaps, she could see yarlan zey looking` out through the entrance, across the park he had built, and beyond that to the city over which he had watched for so many ages. And there was no one else in all this marble solitude. The tomb was empty.