"I thought so!" he exclaimed. "Do you see how all these radiating lines lead toward the small tunnels?"
Alvin had noticed that besides the great arches of the moving ways there were innumerable smaller tunnels leading out of the chamber—tunnels that sloped downward instead of up.
Rorden continued without waiting for a reply.
"It was a magnificent 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 happens then?" said Alvin.
As usual, Rorden refused to speculate.
"I haven't enough information," he answered. "I wish we could read the names of those cities!" he complained, changing the subject abruptly.
Alvin had wandered away and was circumnavigating the central pillar. Presently his voice came to Rorden, slightly muffled and overlaid with echoes from the walls of the chamber.
"What is it?" called Rorden, not wishing to move, because he had nearly deciphered 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 toward the points of the compass. But this time not all of it was too dim to be clearly seen, for one of the lines, and one only, 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 Rorden stood gazing down at that silent symbol. To Rorden it was no more than another question for his machines, but to Alvin its promise was boundless. He tried to imagine this great chamber as it had been in the ancient days, when air transport had come to an end but the cities of Earth still had commerce one with the other. 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. He wondered how long it had gleamed there among its darkened companions, waiting to guide the steps that never came, until at last Yarlan Zey had sealed the moving ways and closed Diaspar against the world.
That had been hundreds of millions of 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.
Rorden broke into his reverie at last. He seemed a little nervous and ill at ease.
"It's time we went back," he said. "I don't think we should go any further now."
Alvin recognized the undertones in his friend's voice, and did not argue with him. He was eager to go forward, but realized that it might not be wise without further preparation. Reluctantly he turned again toward the central pillar. As he walked to the opening of the shaft, the floor beneath him gradually clouded into opacity, and the gleaming enigma far below slowly faded from sight.
4
Now that the way lay open at last before him, Alvin felt a strange reluctance to leave the familiar world of Diaspar. He began to discover that he himself was not immune from the fears he had so often derided in others.
Once or twice Rorden had tried to dissuade him, but the attempt had been halfhearted. It would have seemed strange to a man of the Dawn Ages that neither Alvin nor Rorden saw any danger in what they were doing. For millions of years the world had held nothing that could threaten man, and even Alvin could not imagine types of human beings greatly different from those he knew in Diaspar. That he might be detained against his will was a thought wholly inconceivable to him. At the worst, he could only fail to discover anything.
Three days later, they stood once more in the deserted chamber of the moving ways. Beneath their feet the arrow of light still pointed to Lys—and now they were ready to follow it.
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 half a minute: when it ended they were standing at one end of a long, narrow chamber in the form of a half-cylinder. At the far 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 Rorden they were 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 nonetheless 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 whole 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.
"Well," said Rorden, rather lamely, "are you ready?"
Alvin nodded.
"I wish you'd come," he said—and at once regretted it when he saw the disquiet on the other's face. Rorden was the closest friend he had ever possessed, but he could never break through the barriers that surrounded all his race.
"I'll be back within six hours," Alvin promised, speaking with difficulty, for there was a mysterious tightness in his throat. "Don't bother to wait for me. If I get back early I'll call you—there must be some communicators around here."
It was all very casual and matter-of-fact, Alvin told himself. Yet he could not help jumping when the walls of the machine faded and the beautifully designed interior lay open before his eyes.
Rorden was speaking, rather quickly and jerkily.
"You'll have no difficulty in controlling the machine," he said. "Did you see how it obeyed that thought of mine? I should get inside quickly in case the time delay is fixed."
Alvin stepped aboard, placing his belongings on the nearest seat. He turned to face Rorden, who was standing in the barely visible frame of the doorway. 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 walls of the machine had closed again. Even as Rorden began to wave 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.
Slowly Rorden made his way back to the chamber of the moving ways with its great central pillar. Sunlight was streaming down the open shaft as he rose to the surface. When he emerged again into the Tomb of Yarlan Zey, he was disconcerted, though not surprised, to find a group of curious onlookers gathered around him.
"There's no need to be alarmed," he said gravely. "Someone has to do this every few thousand years, though it hardly seems necessary. The foundations of the city are perfectly stable—they haven't shifted a micron since the Park was built."
He walked briskly away, and as he left the tomb a quick backward glance showed him that the spectators were already dispersing. Rorden knew his fellow citizens well enough to be sure that they would think no more about the incident.