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. She 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.

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:

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.

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:

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: