The City and the Stars/The Sands of Mars

by Arthur C. Clarke

  “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 loose!”

  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.

  “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 Alvin, 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 there 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.”

  Alvin 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 Alvin 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 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.”

  Alvin 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; Diaspar was just as he had always 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 different design. The transformation was so abrupt that had Alvin 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 Khedron. “We’re going back in time.”

  “A picturesque but hardly accurate way of putting it,” replied 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’ll 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.

  “Ah, 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 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 billion-year-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?”

  Khedron’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 difference, 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.

  CHAPTER

  9

  Alystra had found it very easy to follow Alvin and Khedron without their knowledge. They seemed in a great hurry— something 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.

  At that moment, Alvin and Khedron were a hundred feet underground, in a small, boxlike room whose walls seemed to be flowing steadily upward. That was the only indication of movement; there was no trace of vibration to show that they were sinking swiftly into the earth, descending toward a goal that even now neither of them fully understood.

  It had been absurdly easy, for the way had been prepared for them. (By whom? wondered Alvin. By the Central Computer? Or by Yarlan Zey himself, when he transformed the city?) The monitor screen had shown them the long, vertical shaft plunging into the depths, but they had followed its course only a little way when the image had blanked out. That meant, Alvin knew, that they were asking for information that the monitor did not possess, and perhaps never had possessed.

  He had scarcely framed this thought when the screen came to life once more. On it appeared a brief message, printed in the simplified script that machines had used to communicate with men ever since they had achieved intellectual equality:

  STAND WHERE THE STATUE GAZES— AND REMEMBER:

  DIASPAR WAS NOT ALWAYS THUS

  The last five words were in larger type, and the meaning of the entire message was obvious to Alvin at once. Mentally framed code messages had been used for ages to unlock doors or set machines in action. As for “Stand where the statue gazes”— that was really too simple.

  “I wonder how many people have read this message?” said Alvin thoughtfully.

  “Fourteen, to my knowledge,” replied Khedron. “And there may have been others.” He did not amplify this rather cryptic remark, and Alvin was in too great a hurry to reach the park to question him further.

  They could not be certain that the mechanisms would still respond to the triggering impulse. When they reached the Tomb, it had taken them only a moment to locate the single slab, among all those paving the floor, upon which the gaze of Yarlan Zey was fixed. It was only at first sight that the statue seemed to be looking out across the city; if one stood directly in front of it, one could see that the eyes were downcast and that the elusive smile was directed toward a spot just inside the entrance to the Tomb. Once the secret was realized, there could be no doubt about it. Alvin moved to the next slab, and found that Yarlan Zey was no longer looking toward him.

  He rejoined Khedron, and mentally echoed the words that the Jester spoke aloud: “Diaspar was not always thus.” Instantly, as if the millions of years that had lapsed since their last operation had never existed, the waiting machines responded. The great slab of st
one on which they were standing began to carry them smoothly into the depths.

  Overhead, the patch of blue suddenly flickered out of existence. The shaft was no longer open; there was no danger that anyone should accidentally stumble into it. Alvin wondered fleetingly if another slab of stone had somehow been materialized to replace the one now supporting him and Khedron, then decided against it. The original slab probably still paved the Tomb; the one upon which they were standing might only exist for infinitesimal fractions of a second, being continuously recreated at greater and greater depths in the earth to give the illusion of steady downward movement.

  Neither Alvin nor Khedron spoke as the walls flowed silently past them. Khedron was once again wrestling with his conscience, wondering if this time he had gone too far. He could not imagine where this route might lead, if indeed it led anywhere. For the first time in his life, he began to understand the real meaning of fear.

  Alvin was not afraid; he was too excited. This was the sensation he had known in the Tower of Loranne, when he had looked out across the untrodden desert and seen the stars conquering the night sky. He had merely gazed at the unknown then; he was being carried toward it now.

  The walls ceased to flow past them. A patch of light appeared at one side of their mysteriously moving room, grew brighter and brighter, and was suddenly a door. They stepped through it, took a few paces along the short corridor beyond— and then were standing in a great, circular cavern whose walls came together in a sweeping curve three hundred feet above their heads.

  The column down whose interior they had descended seemed far too slim to support the millions of tons of rock above it; indeed, it did not seem to be an integral part of the chamber at all, but gave the impression of being an afterthought. Khedron, following Alvin’s gaze, arrived at the same conclusion.