Khedron continued without waiting for a reply.

  “It would be hard to think of a simpler system. People would come down the moving ways, select the place they wished to visit, and then follow the appropriate line on the map.”

  “And what happened to them after that?” asked Alvin. Khedron was silent, his eyes searching out the mystery of those descending tunnels. There were thirty or forty of them, all looking exactly the same. Only the names on the map would have enabled one to distinguish between them, and those names were indecipherable now.

  Alvin had wandered away and was circumnavigating the central pillar. Presently his voice came to Khedron, slightly muffled and overlaid with echoes from the walls of the chamber.

  “What is it?” called Khedron, not wishing to move, because he had nearly succeeded in reading one of the dimly visible groups of characters. But Alvin’s voice was insistent, so he went to join him.

  Far beneath was the other half of the great map, its faint webwork radiating to the points of the compass. This time, however, not all of it was too dim to be clearly seen, for one of the lines— and only one— was brilliantly illuminated. It seemed to have no connection with the rest of the system, and pointed like a gleaming arrow to one of the downward-sloping tunnels. Near its end the line transfixed a circle of golden light, and against that circle was the single word LYS. That was all.

  For a long time Alvin and Khedron stood gazing down at that silent symbol. To Khedron it was a challenge he knew he could never accept— and which, indeed, he would rather did not exist. But to Alvin it hinted at the fulfillment of all his dreams; though the word Lys meant nothing to him, he let it roll around his mouth, tasting its sibilance like some exotic flavor. The blood was pounding in his veins, and his cheeks were flushed as by a fever. He stared around this great concourse, trying to imagine it as it had been in the ancient days, when air transport had come to an end but the cities of Earth still had contact with one another. He thought of the countless millions of years that had passed with the traffic steadily dwindling and the lights on the great map dying one by one, until at last only this single line remained. How long, he wondered, had it gleamed there among its darkened companions, waiting to guide the steps that never came, until Yarlan Zey had sealed the moving ways and closed Diaspar against the world?

  And that had been a billion years ago. Even then, Lys must have lost touch with Diaspar. It seemed impossible that it could have survived; perhaps, after all, the map meant nothing now.

  Khedron broke into his reverie at last. He seemed nervous and ill at ease, not at all like the confident and self-assured person that he had always been in the city above.

  “I do not think that we should go any farther now,” he said. “It may not be safe until— until we are more prepared.”

  There was wisdom in this, but Alvin recognized the underlying note of fear in Khedron’s voice. Had it not been for that, he might have been sensible, but a too-acute awareness of his own valor, combined with a contempt for Khedron’s timidity, drove Alvin onward. It seemed foolish to have come so far, only to turn back when the goal might be in sight.

  “I’m going down that tunnel,” he said stubbornly, as if challenging Khedron to stop him. “I want to see where it leads.” He set off resolutely, and after a moment’s hesitation the Jester followed him along the arrow of light that burned beneath their feet.

  As they stepped into the tunnel, they felt the familiar tug of the peristaltic field, and in a moment were being swept effortlessly into the depths. The journey lasted scarcely a minute; when the field released them they were standing at one end of a long narrow chamber in the form of a half-cylinder. At its distant end, two dimly lit tunnels stretched away toward infinity.

  Men of almost every civilization that had existed since the Dawn would have found their surroundings completely familiar, yet to Alvin and Khedron this was a glimpse of another world. The purpose of the long, streamlined machine that lay aimed like a projectile at the far tunnel was obvious, but that made it none the less novel. Its upper portion was transparent, and looking through the walls Alvin could see rows of luxuriously appointed seats. There was no sign of any entrance, and the entire machine was floating about a foot above a single metal rod that stretched away into the distance, disappearing in one of the tunnels. A few yards away another rod led to the second tunnel, but no machine floated above it. Alvin knew, as surely as if he had been told, that somewhere beneath unknown, far-off Lys, that second machine was waiting in another such chamber as this.

  Khedron began to talk, a little too swiftly.

  “What a peculiar transport system! It could only handle a hundred people at a time, so they could not have expected much traffic. And why did they go to all this trouble to bury themselves in the Earth if the skies were still open? Perhaps the Invaders would not even permit them to fly, though I find that hard to believe. Or was this built during the transition period, while men still traveled but did not wish to be reminded of space? They could go from city to city, and never see the sky and the stars.” He gave a nervous laugh. “I feel sure of one thing, Alvin. When Lys existed, it was much like Diaspar. All cities must be essentially the same. No wonder that they were all abandoned in the end, and merged into Diaspar. What was the point of having more than one?”

  Alvin scarcely heard him. He was busy examining the long projectile, trying to find the entrance. If the machine was controlled by some central or verbal code order, he might never be able to make it obey him, and it would remain a maddening enigma for the rest of his life.

  The silently opening door took him completely unawares. There was no sound, no warning when a section of the wall simply faded from sight and the beautifully designed interior lay open before his eyes.

  This was the moment of choice. Until this instant, he had always been able to turn back if he wished. But if he stepped inside that welcoming door, he knew what would happen, though not where it would lead. He would no longer be in control of his own destiny, but would have placed himself in the keeping of unknown forces.

  He scarcely hesitated. He was afraid to hold back, being fearful that if he waited too long this moment might never come again— or that if it did, his courage might not match his desire for knowledge. Khedron opened his mouth in anxious protest, but before he could speak, Alvin had stepped through the entrance. He turned to face Khedron, who was standing framed in the barely visible rectangle of the doorway, and for a moment there was a strained silence while each waited for the other to speak.

  The decision was made for them. There was a faint flicker of translucence, and the wall of the machine had closed again. Even as Alvin raised his hand in farewell, the long cylinder started to ease itself forward. Before it had entered the tunnel, it was already moving faster than a man could run.

  There had been a time when, every day, millions of men made such journeys, in machines basically the same as this, as they shuttled between their homes and their humdrum jobs. Since that far-off day, Man had explored the Universe and returned again to Earth— had won an empire, and had it wrestled from his grasp. Now such a journey was being made again, in a machine wherein legions of forgotten and unadventurous men would have felt completely at home.

  And it was to be the most momentous journey any human being had undertaken for a billion years.

  Alystra had searched the Tomb a dozen times, though once was quite sufficient, for there was nowhere anyone could hide. After the first shock of surprise, she had wondered if what she had followed across the park had not been Alvin and Khedron at all, but only their projections. But that made no sense; projections were materialized at any spot one wished to visit, without the trouble of going there in person. No sane person would “walk” his projected image a couple of miles, taking half an hour to reach his destination, when he could be there instantly. No; it was the real Alvin and the real Khedron that she had followed into the Tomb.

  Somewhere, then, there must be a secret entrance. Sh
e might as well look for it while she was waiting for them to come back.

  As luck would have it, she missed Khedron’s reappearance, for she was examining a column behind the statue when he emerged on the other side of it. She heard his footsteps, turned toward him, and saw at once that he was alone.

  “Where is Alvin?” she cried.

  It was some time before the Jester answered. He looked distraught and irresolute, and Alystra had to repeat her question before he took any notice of her. He did not seem in the least surprised to find her there.

  “I do not know where he is,” he answered at last. “I can only tell you that he is on his way to Lys. Now you know as much as I do.”

  It was never wise to take Khedron’s words at their face value. But Alystra needed no further assurance that the Jester was not playing his role today. He was telling her the truth— whatever it might mean.

  CHAPTER

  10

  When the door closed behind him, Alvin slumped into the nearest seat. All strength seemed suddenly to have been drained from his legs: at last he knew, as he had never known before, that fear of the unknown that haunted all his fellow men. He felt himself trembling in every limb, and his sight became misty and uncertain. Could he have escaped from this speeding machine he would willingly have done so, even at the price of abandoning all his dreams.

  It was not fear alone that overwhelmed him, but a sense of unutterable loneliness. All that he knew and loved was in Diaspar; even if he was going into no danger, he might never see his world again. He knew, as no man had known for ages, what it meant to leave one’s home forever. In this moment of desolation, it seemed to him of no importance whether the path he was following led to peril or to safety; all that mattered to him now was that it led away from home.

  The mood slowly passed; the dark shadows lifted from his mind. He began to pay attention to his surroundings, and to see what he could learn from the unbelievably ancient vehicle in which he was traveling. It did not strike Alvin as particularly strange or marvelous that this buried transport system should still function perfectly after such aeons of time. It was not preserved in the eternity circuits of the city’s own monitors, but there must be similar circuits elsewhere guarding it from change or decay.

  For the first time he noticed the indicator board that formed part of the forward wall. It carried a brief but reassuring message:

  LYS

  35 MINUTES

  Even as he watched, the number changed to “34.” That at least was useful information, though since he had no idea of the machine’s speed it told him nothing about the length of the journey. The walls of the tunnel were one continual blur of gray, and the only sensation of movement was a very slight vibration he would never have noticed had he not looked for it.

  Diaspar must be many miles away by now, and above him would be the desert with its shifting sand dunes. Perhaps at this very moment he was racing below the broken hills he had watched so often from the Tower of Loranne.

  His imagination sped onward to Lys, as if impatient to arrive ahead of his body. What sort of a city would it be? No matter how hard he tried, he could only picture another and smaller version of Diaspar. He wondered if it still existed, then assured himself that not otherwise would this machine be carrying him swiftly through the Earth.

  Suddenly there was a distinct change in the vibration underfoot. The vehicle was slowing down— there was no question of that. The time must have passed more swiftly than he had thought; somewhat surprised, Alvin glanced at the indicator.

  LYS

  23 MINUTES

  Feeling puzzled, and a little worried, he pressed his face against the side of the machine. His speed was still blurring the walls of the tunnel into a featureless gray, yet now from time to time he could catch a glimpse of markings that disappeared almost as quickly as they came. And at each disappearance, they seemed to remain in his field of vision for a little longer.

  Then, without any warning, the walls of the tunnel were snatched away on either side. The machine was passing, still at a very great speed, through an enormous empty space, far larger even than the chamber of the moving ways.

  Peering in wonder through the transparent walls, Alvin could glimpse beneath him an intricate network of guiding rods, rods that crossed and crisscrossed to disappear into a maze of tunnels on either side. A flood of bluish light poured down from the arched dome of the ceiling, and silhouetted against the glare he could just make out the frameworks of great machines. The light was so brilliant that it pained the eyes, and Alvin knew that this place had not been intended for man. A moment later, his vehicle flashed past row after row of cylinders, lying motionless above their guide rails. They were much larger than the one in which he was traveling, and Alvin guessed that they must have been used for transporting freight. Around them were grouped incomprehensible, many-jointed mechanisms, all silent and stilled.

  Almost as quickly as it had appeared, the vast and lonely chamber vanished behind him. Its passing left a feeling of awe in Alvin’s mind; for the first time he really understood the meaning of that great, darkened map below Diaspar. The world was more full of wonder than he had ever dreamed.

  Alvin glanced again at the indicator. It had not changed; he had taken less than a minute to flash through the great cavern. The machine was accelerating again; though there was little sense of motion, the tunnel walls were flowing past on either side at a speed he could not even guess.

  It seemed an age before that indefinable change of vibration occurred again. Now the indicator was reading:

  LYS

  1 MINUTE

  That minute was the longest that Alvin had ever known. More and more slowly moved the machine; this was no mere slackening of its speed. It was coming at last to rest.

  Smoothly and silently the long cylinder slid out of the tunnel into a cavern that might have been the twin of the one below Diaspar. For a moment Alvin was too excited to see anything clearly; the door had been open for a considerable time before he realized that he could leave the vehicle. As he hurried out of the machine, he caught a last glimpse of the indicator. Its wording had now changed and its message was infinitely reassuring:

  DIASPAR

  35 MINUTES

  As he began to search for a way out of the chamber, Alvin found the first hint that he might be in a civilization different from his own. The way to the surface clearly lay through a low, wide tunnel at one end of the cavern— and leading up through the tunnel was a flight of steps. Such a thing was extremely rare in Diaspar; the architects of the city had built ramps or sloping corridors whenever there was a change of level. This was a survival from the days when most robots had moved on wheels, and so found steps an impassable barrier.

  The stairway was very short, and ended against doors that opened automatically at Alvin’s approach. He walked into a small room like that which had carried him down the shaft under the Tomb of Yarlan Zey, and was not surprised when a few minutes later the doors opened again to reveal a vaulted corridor rising slowly to an archway that framed a semicircle of sky. There had been no sensation of movement, but Alvin knew that he must have risen many hundreds of feet. He hurried forward up the slope to the sunlit opening, all fear forgotten in his eagerness to see what lay before him.

  He was standing at the brow of a low hill, and for an instant it seemed as if he were once again in the central park of Diaspar. Yet if this were indeed a park, it was too enormous for his mind to grasp. The city he had expected to see was nowhere visible. As far as the eye could reach there was nothing but forest and grass-covered plains.

  Then Alvin lifted his eyes to the horizon, and there above the trees, sweeping from right to left in a great arc that encircled the world, was a line of stone which would have dwarfed the mightiest giants of Diaspar. It was so far away that its details were blurred by sheer distance, but there was something about its outlines that Alvin found puzzling. Then his eyes became at last accustomed to the scale of that colossal land
scape, and he knew that those far-off walls had not been built by man.

  Time had not conquered everything; Earth still possessed mountains of which she could be proud.

  For a long time Alvin stood at the mouth of the tunnel, slowly growing accustomed to the strange world in which he had found himself. He was half stunned by the impact of sheer size and space; that ring of misty mountains could have enclosed a dozen cities as large as Diaspar. Search as he might, however, Alvin could see no trace of human life. Yet the road that led down the hillside seemed well-kept; he could do no better than accept its guidance.

  At the foot of the hill, the road disappeared between great trees that almost hid the sun. As Alvin walked into their shadow, a strange medley of scents and sounds greeted him. The rustle of the wind among the leaves he had known before, but underlying that were a thousand vague noises that conveyed nothing to his mind. Unknown odors assailed him, smells that had been lost even to the memory of his race. The warmth, the profusion of scent and color, and the unseen presences of a million living things, smote him with almost physical violence.

  He came upon the lake without any warning. The trees to the right suddenly ended, and before him was a great expanse of water, dotted with tiny islands. Never in his life had Alvin seen so much water; by comparison, the largest pools in Diaspar were scarcely more than puddles. He walked slowly down to the edge of the lake and cupped the warm water in his hands, letting it trickle through his fingers.

  The great silver fish that suddenly forced its way through the underwater reeds was the first nonhuman creature that Alvin had ever seen. It should have been utterly strange to him, yet its shape teased his mind with a haunting familiarity. As it hung there in the pale green void, its fins a faint blur of motion, it seemed the very embodiment of power and speed. Here, incorporated in living flesh, were the graceful lines of the great ships that had once ruled the skies of Earth. Evolution and science had come to the same answers; and the work of Nature had lasted longer.