It was not unpleasant walking with the wind behind them, and they soon reached the end of the tunnel. A wide-meshed filigree of stone prevented them from going farther, which was just as well, for they stood on the brink of nothingness. The great air duct opened on the sheer face of the tower, and below them was a vertical drop of at least a thousand feet. They were high upon the outer ramparts of the city, and Diaspar lay spread beneath them as few in their world could ever have seen it.

The view was the obverse of the one that Alvin had obtained from the center of the park. He could look down upon the concentric waves of stone and metal as they descended in mile-long sweeps toward the heart of the city. Far away, partly hidden by the intervening towers, he could glimpse the distant fields and trees and the eternally circling river. Further still, the remoter bastions of Diaspar climbed once more toward the sky.

Beside him, Alystra was sharing the view with pleasure but with no surprise. She had seen the city countless times before from other, almost equally well-placed vantage points-and in considerably more comfort.

«That’s our world-all of it,» said Alvin. «Now I want to show you something else.» He turned away from the grat-ing and began to walk toward the distant circle of light at the far end of the tunnel. The wind was cold against his lightly clad body, but he scarcely noticed the discomfort as he walked forward into the air stream.

He had gone only a little way when he realized that Alystra was making no attempt to follow. She stood watching, her borrowed cloak streaming down the wind, one hand half raised to her face. Alvin saw her lips move, but the words did not reach him. He looked back at her first with astonish-ment then with an impatience that was not totally devoid of pity. What Jeserac had said was true. She could not fol-low him. She had realized the meaning of that remote circle of light from which the wind blew forever into Diaspar. Behind Alystra was the known world, full of wonder yet empty of surprise, drifting like a brilliant but tightly closed bubble down the river of time. Ahead, separated from her by no more than the span of a few footsteps, was the empty wilderness-the world of the desert-the world of the Invaders.

Alvin walked back to join her and was surprised to find that she was trembling. «Why are you frightened?» he asked. «We’re still safely here in Diaspar. You’ve looked out of that window behind us surely you can look out of this one as well!»

Alystra was staring at him as if he was some strange mon-ster. By her standards, indeed, he was.

«I couldn’t do it,» she said at last. «Even thinking about it makes me feel colder than this wind. Don’t go any farther, Alvin!»

«But there’s no logic in it!» Alvin persisted remorselessly. «What possible harm would it do you to walk to the end of this corridor and look out? It’s strange and lonely out there but it isn’t horrible. In fact, the longer I look the more beautiful I think-»

Alystra did not stay to hear him finish. She turned on her heels and fled back down the long ramp that had brought them up through the floor of this tunnel. Alvin made no attempt to stop her, since that would have involved the bad manners of imposing one’s will upon another. Persuasion, he could see would have been utterly useless. He knew that Alystra would not pause until she had returned to her com-panions. There was no danger that she would lose herself m the labyrinths of the city, for she would have no dif-ficulty in retracing her footsteps. An instinctive ability to extricate himself from even the most complex of mazes had been merely one of the many accomplishments Man had learned since he started to live in cities. The long-extinct rat had been forced to acquire similar skills when he left the fields and threw in his lot with humanity.

Alvin waited for a moment, as if half-expecting Alystra to return. He was not surprised at her reaction only at its violence and irrationality. Though he was sincerely sorry that she had gone, he could not help wishing that she had re membered to leave the cloak. It was not only cold, but it was also hard work moving against the wind which sighed through the lungs of the city. Alvin was fighting both the air current and whatever force it was that kept it moving. Not until he had reached the stone grille and could lock his arms around its bars, could he afford to relax. There was just sufficient room for him to force his head through the opening, and even so his view was slightly restricted, as the entrance to the duct was partly recessed into the city’s wall.

Yet he could see enough. Thousands of feet below, the sunlight was taking leave of the desert. The almost horizontal rays struck through the grating and threw a weird pattern of gold and shadow far down the tunnel. Alvin shaded his eyes against the glare and peered down at the land upon which no man had walked for unknown ages.

He might have been looking at an eternally frozen sea. For mile after mile, the sand dunes undulated into the west, their contours grossly exaggerated by the slanting light. Here and there some caprice of the wind had carved curious whirlpools and gullies in the sand, so that it was sometimes hard to realize that none of this sculpture was the work of intelligence. At a very great distance, so far away indeed that he had no way of judging their remoteness, was a range of softly rounded hills. They had been a disappointment to Alvin; he would have given much to have seen in reality the soaring mountains of the ancient records and of his own dreams.

The sun lay upon the rim of the hills, its light tamed and reddened by the hundreds of miles of atmosphere it was traversing. There were two great black spots upon its disc; Alvin had learned from his studies that such things existed, but he was surprised that he could see them so easily. They seemed almost like a pair of eyes peering back at him as he crouched in his lonely spy hole with the wind whistling ceaselessly past his ears.

There was no twilight. With the going of the sun, the pools of shadow lying among the sand dunes flowed swiftly together in one vast lake of darkness. Color ebbed from the sky; the warm reds and golds drained away leaving an antarctic blue that deepened and deepened into night. Alvin waited for that breathless moment that he alone of all man-kind had known-the moment when the first star shivers into life.

It had been many weeks since he had last come to this place, and he knew that the pattern of the night sky must have changed meanwhile. Even so, he was not prepared for his first glimpse of the Seven Suns.

They could have no other name; the phrase leaped un-bidden to his lips. They formed a tiny, very compact and astonishingly symmetrical group against the afterglow of sun-set. Six of them were arranged in a slightly flattened ellipse, which, Alvin was sure, was in reality a perfect circle, slightly tilted toward the line of vision. Each star was a different color; he could pick out red, blue, gold, and green, but the other tints eluded his eye. At the precise center of the forma-tion was a single white giant-the brightest star in all the visible sky. The whole group looked exactly like a piece of jewelry; it seemed incredible, and beyond all stretching of the laws of chance, that Naure could ever have contrived so perfect a pattern.

As his eyes grew slowly accustomed to the darkness, Alvin could make out the great misty veil that had once been called the Milky Way. It stretched from the zenith down to the horizon, and the Seven Suns were entangled in its folds.

The other stars had now emerged to challenge them, and their random groupings only emphasized the enigma of that perfect symmetry. It was almost as if some power had de-liberately opposed the disorder of the natural Universe by setting its sign upon the stars.