The City and the Stars

by Arthur Charles Clarke

  Foiled of its intended victim, the creature sank slowly into the ground-and it was then that Alvin realized that the plain below was merely the thin scum on the surface of a stagnant sea.

  «What was that-thing?» he gasped.

  «I’d have to go down and study it before I could tell you that,» Hilvar replied matter-of-factly. «It may have been some form of primitive animal-perhaps even a relative of our friend in Shalmirane. Certainly it was not intelligent, or it would have known better than to try to eat a spaceship.»

  Alvin felt shaken, though he knew that they had been in no possible danger. He wondered what else lived down there beneath that innocent sward, which seemed to positively invite him to come out and run upon its springy surface.

  «I could spend a lot of time here,» said Hilvar, obviously fascinated by what he had just seen. «Evolution must have produced some very interesting results under these conditions. Not only evolution, but devolution as well, as higher forms of life regressed when the planet was deserted. By now equilibrium must have been reached and-you’re not leaving already?» His voice sounded quite plaintive as the landscape receded below them.

  «I am,» said Alvin. «I’ve seen a world with no life, and a world with too much, and I don’t know which I dislike more.»

  Five thousand feet above the plain, the planet gave them one final surprise. They encountered a flotilla of huge, flabby balloons drifting down the wind. From each semitransparent envelope clusters of tendrils dangled to form what was virtually an inverted forest. Some plants, it seemed, in the effort to escape from the ferocious conflict on the surface had learned to conquer the air. By a miracle of adaptation, they had managed to prepare hydrogen and store it in bladders, so that they could lift themselves into the comparative peace. of the lower atmosphere.

  Yet it was not certain that even here they had found security. Their downward-hanging stems and leaves were infested with an entire fauna of spidery animals, which must! spend their lives floating far above the surface of the globe, continuing the universal battle for existence on their lonely aerial islands. Presumably they must from time to time have some contact with the ground; Alvin saw one of the great balloons suddenly collapse and fall out of the sky, its broken, envelope acting as a crude parachute. He wondered if this was an accident, or part of the life cycle of these strange entities.

  Hilvar slept while they waited for the next planet to approach. For some reason which the robot could not explain to them, the ship traveled slowly-at least by comparison with its Universe-spanning haste-now that it was within a Solar System. It took almost two hours to reach the world that Alvin had chosen for his third stop, and he was a little surprised that any mere interplanetary journey should last so long.

  He woke Hilvar as they dropped down into the atmosphere.

  «What do you make of that?» he asked, pointing to the vision screen.

  Below them was a bleak landscape of blacks and gray, showing no sign of vegetation or any other direct evidence of life. But there was indirect evidence; the low hills an shallow valleys were dotted with perfectly formed hemispheres, some of them arranged in complex, symmetrical patterns.

  They had learned caution on the last planet, and aft carefully considering all the possibilities remained high in the atmosphere while they sent the robot down to investigate. Through its eyes, they saw one of the hemispheres approach until the robot was floating only a few feet awa from the completely smooth featureless surface.

  There was no sign of any entrance, nor any hint of the pur pose which the structure served. It was quite large– a hundred feet high; some of the other hemispheres we larger still. If it was a building, there appeared to be no wa in or out.

  After some hesitation, Alvin ordered the robot to move forward and touch the dome. To his utter astonishment, it refused to obey him. This indeed was mutiny-or so at sight it seemed.

  «Why won’t you do what I tell you?» asked Alvin, wh he had recovered from his astonishment.

  «It is forbidden,» came the reply.

  «Forbidden by whom?»

  «I do not know.»

  «Then how-no, cancel that. Was the order built into you?»

  «No.»

  That seemed to eliminate one possibility. The builders of these domes might well have been the race who made the robot, and might have included this taboo in the machine’s original instructions.

  «When did you receive the order?» asked Alvin.

  «I received it when I landed.»

  Alvin turned to Hilvar, the light of a new hope burning in his eyes.

  «There’s intelligence here! Can you sense it?»

  «No,» Hilvar replied. «This place seems as dead to me as the first world we visited.»

  «I’m going outside to join the robot. Whatever spoke to it may speak to me.»

  Hilvar did not argue the point, though he looked none too happy. They brought the ship to earth a hundred feet away from the dome, not far from the waiting robot, and opened the air lock.

  Alvin knew that the lock could not be opened unless the ship’s brain had already satisfied itself that the atmosphere was breathable. For a moment he thought it had made a mistake-the air was so thin and gave such little sustenance to his lungs. Then, by inhaling deeply, he found that he could grasp enough oxygen to survive, though he felt that a few minutes here would be all that be could endure.

  Panting hard, they walked up to the robot and to the curving wall of the enigmatic dome. They took one more stepthen stopped in unison as if hit by the same sudden blow. In their minds, like the tolling of a mighty gong, had boomed a single message:

  DANGER. COME NO CLOSER.

  That was all. It was a message not in words, but in pure thought. Alvin was certain that any creature, whatever its level of intelligence, would receive the same warning, in the same utterly unmistakable fashion-deep within its mind.

  It was a warning, not a threat. Somehow they knew that it was not directed against them; it was for their own protection.

  Here, it seemed to say, is something intrinsically dangerous, and we, its makers, are anxious that no one shall be hurt through blundering ignorantly into it.

  Alvin and Hilvar stepped back several paces, and looked at each other, each waiting for the other to say what was in his mind. Hilvar was the first to sum up the position.

  «I was right, Alvin,» he said. «There is no intelligence here. That warning is automatic-triggered by our presence when we get too close.»

  Alvin nodded in agreement.

  «I wonder what they were trying to protect,» he said.: «There could be buildings-anything-Under these domes.»

  «There’s no way we can find out, if all the domes warn us off. It’s interesting-the difference between the three planets we’ve visited. They took everything away from the first-they abandoned the second without bothering about it -but they went to a lot of trouble here. Perhaps they expected to come back some day, and wanted everything to be ready for them when they returned.»

  «But they never did-and that was a long time ago.»

  «They may have changed their minds.»

  It was curious Alvin thought, how both he and Hilvar had unconsciously started using the word «they.» Whoever or whatever «they» had been, their presence had been strong on that first planet-and was even stronger here. This was a world that had been carefully wrapped up, and put away until it might be needed again.

  «Let’s go back to the ship,» panted Alvin. «I can’t breathe properly here.»

  As soon as the air lock had closed behind them, and they were at ease once more, they discussed their next move. To. make a thorough investigation, they should sample a large number of domes, in the hope that they might find one that had no warning and which could be entered. If that failed Alvin would not face that possibility until he had to.

  He faced it less than an hour later, and in a far more dramatic form than he would have dreamed. They had sent: the robot down to half a dozen domes, always wi
th the same, result, when they came across a scene that was badly out of place on this tidy, neatly packaged world.

  Below them was a broad valley, sparsely sprinkled with’ the tantalizing, impenetrable domes. At its center was the unmistakable scar of a great explosion-an explosion that had thrown debris for miles in all directions and burned a shallow crater in the ground.

  And beside the crater was the wreckage of a spaceship.

  Twenty-one

  They landed close to the scene of this ancient tragedy and walked slowly, conserving their breath toward mense, broken hull towering above them. Only a short section -either the prow or the stern-of the ship remained; presumably the rest had been destroyed in the explosion. As they approached the wreck, a thought slowly dawned in Alvin’s mind, becoming stronger and stronger until it attained the status of certainty.

  «Hilvar,» he said, finding it hard to talk and walk at the same time, «I believe this is the ship that landed on the first planet we visited.»

  Hilvar nodded, preferring not to waste air. The same idea had already occurred to him. It was a good object lesson, he thought, for incautious visitors. He hoped it would not be lost on Alvin.

  They reached the hull and stared up into the exposed interior of the ship. It was like looking into a huge building that had been roughly sliced in two; floors and walls and ceilings, broken at the point of the explosion, gave a distorted chart of the ship’s cross section. What strange beings, wondered Alvin, still lay where they had died in the wreckage of their vessel?

  «I don’t understand this,» said Hilvar suddenly. «This portion of the ship is badly damaged, but it’s still fairly intact. Where’s the rest of it? Did it break in two out in space, and this part crash here?»

  Not until they had sent the robot exploring again, and had themselves examined the area around the wreckage, did they learn the answer. There was no shadow of doubt; any reservations they might have had were banished when Alvin found the line of low mounds, each ten feet long, on the little hill beside the ship.

  «So they landed here,» mused Hilvar, «and ignored the warning. They were inquisitive, just as you are. They tried to open that dome.»

  He pointed to the other side of the crater, to the smooth, still unmarked shell within which the departed rulers of this world had sealed their treasures. But it was no longer a dome; it was now an almost complete sphere, for the ground in which it had been set had been blasted away.

  «They wrecked their ship, and many of them were killed. Yet despite that, they managed to make repairs and leave again, cutting off this section and stripping out everything of value. What a task that must have been!»

  Alvin scarcely heard him. He was looking at the curious marker that had first drawn him to this spot-the slim shaft Pinged by a horizontal circle a third of the way down from its up. Alien and unfamiliar though it was, be could respond to the mute message it had carried down the ages. Underneath those stones, if he cared to disturb them, was the answer to one question at least. It could remain unanswered; whatever these creatures might have been, they had earned their right to rest.

  Hilvar scarcely heard the words Alvin whispered as walked slowly back to the ship.

  «I hope they got home,» he said.

  «And where now?» asked Hilvar, when they were once more out in space.

  Alvin stared thoughtfully at the screen before replying.

  «Do you think I should go back?» he said.

  «It would be the sensible thing to do. Our luck may ad hold out much longer, and who knows what other surprise these planets may have waiting for us?»

  It was the voice of sanity and caution, and Alvin wad now prepared to give it greater heed than he would have done a few days before. But he had come a long way, and waited all his life, for this moment; he would not turn bar while there was still so much to see.

  «We’ll stay in the ship from now on,» he said, «and wn won’t touch surface anywhere. That should be safe enough surely.»

  Hilvar shrugged his shoulders, as if refusing to accept any responsibility for what migt happen next. Now that Alvin was showing a certain amount of caution, he thought it unwise to admit that he was equally anxious to continu! their exploring, though he had long ago abandoned all hopl of meeting intelligent life upon any of these planets.

  A double world lay ahead of them, a great planet with 1 smaller satellite beside it. The primary might have been the twin of the second world they had visited; it was clothed it that same blanket of livid green. There would be no point it landing here; this was a story they already knew.

  Alvin brought the ship low over the surface of the satellite, he needed no warning from the complex mechanism which protected him to know that there was no atmosphere here. Al shadows had a sharp, clean edge, and there were no gradation between night and day. It was the first world on which he had seen something approaching night, for only one of the more distant suns was above the horizon in the area where they made first contact. The landscape was bathed in a dull rep light, as though it had been dipped in blood.

  For many miles they flew above mountains that were sti) as jagged and sharp as in the distant ages of their birth. This was a world that had never known change or decay, hay never been scoured by winds and rains. No eternity circuit were needed here to preserve objects in their pristine fresh ness.

  But if there was no air, then there could have been no life -or could there have been?

  «Of course,» said Hilvar, when Alvin put the question d him, «there’s nothing biologically absurd in the idea. Lift can’t originate in airless space-but it can evolve forms that will survive in it. It must have happened millions of times, whenever an inhabited planet lost its atmosphere.»

  «But would you expect intelligent life forms to exist in a vacuum ? Wouldn’t they have protected themselves against the loss of their air?»

  «Probably, if it occurred after they achieved enough intelligence to stop it happening. But if the atmosphere went while they were still in the primitive state, they would have to adapt or perish. After they had adapted, they might then develop a very high intelligence. In fact, they probably would-the incentive would be so great.»

  The argument, decided Alvin, was a purely theoretical one, as far as this planet was concerned. Nowhere was there any sign that it had ever borne life, intelligent or otherwise. But in that case, what was the purpose of this world? The entire multiple system of the Seven Suns, he was now certain, was artificial, and this world must be part of its grand design.

  It could, conceivably, be intended purely for ornament to provide a moon in the sky of its giant companion. Even in that case, however, it seemed likely that it would be put to some use.

  «Look, said Hilvar, pointing to the screen. «Over there, on the right.»

  Alvin changed the ship’s course, and the landscape tilted around them. The red-lit rocks blurred with the speed of their motion; then the image stabilized, and sweeping below was the unmistakable evidence of life.

  Unmistakable-yet also baffling. It took the form of a wide-spaced row of slender columns, each a hundred feet from its neighbor and twice as high. They stretched into the distance, dwindling in hypnotic perspective, until the far horizon swallowed them up.

  Alvin swung the ship to the right, and began to race along the line of columns, wondering as he did so what purpose they could ever have served. They were absolutely uniform, marching in an unbroken file over hills and down into valleys. There was no sign that they had ever supported anything; they were smooth and featureless, tapering very slightly toward the top.

  Quite abruptly, the line changed its course, turning sharply through a right angle. Alvin overshot by several miles before he reacted and was able to swing the ship around in the new direction.

  The columns continued with the same unbroken stride across the landscape, their spacing perfectly regular. Then, fifty miles from the last change of course, they turned abruptly through another right angle. At this rate, thought Alvin, w
e will soon be back where we started.

  The endless sequence of columns had so mesmerized them fat when it was broken they were miles past the discontinuity before Hilvar cried out and made Alvin, who had noticed nothing, turn the ship back. They descended slowly, and they circled above what Hilvar had found, a fantastic picion began to dawn in their minds-though at first neither dared mention it to the other. Two of the columns had been broken off near their base and lay stretched out upon the rocks where they had fallen. Nor was that all; the two columns adjoining the gap had bent outward by some irresistible force.

  There was no escape from the awesome conclusion. Alvin knew what they had been flying over; it was so thing he had seen often enough in Lys, but until this mom the shocking change of scale had prevented recognition.

  «Hilvar,» he said, still hardly daring to put his thou into words, «do you know what this is?»

  «It seems hard to believe, but we’ve been flying aro the edge of a corral. This thing is a fence-a fence l hasn’t been strong enough.»

  «People who keep pets,» said Alvin, with the nervous lain men sometimes use to conceal their awe, «should make sure they know how to keep them under control.»

  Hilvar did not react to his forced levity; he was staring the broken barricade, his brow furrowed with thought.

  «I don’t understand it,» he said at last. «Where could have got food on a planet like this? And why did it bred out of its pen? I’d give a lot to know what kind of animal was.»

  «Perhaps it was left here, and broke out because it ail hungry,» Alvin surmised. «Or something may have made it annoyed.»

  «Let’s go lower,» said Hilvar. «I want to have a look the ground.»

  They decended until the ship was almost touching barren rock, and it was then that they noticed that the ply was pitted with innumerable small holes no more than an inch or two wide. Outside the stockade, however, the groud was free from these mysterious pockmarks; they stopped ruptly at the line of the fence.