For the benefit of those who have read my first novel, Against the Fall of Night, and will recognize some of the material in the present work, a few words of explanation are in order.

Against the Fall of Night was begun in 1937 and, after four or five drafts, was completed in 1946, though for various reasons beyond the author’s control book publication was delayed until some years later. Although this work was well received, it had most of the defects of a first novel, and my initial dissatisfaction with it increased steadily over the years. Moreover, the progress of science during the two decades since the story was first conceived made many of the original ideas naive, and opened up vistas and possibilities quite unimagined when the book was originally planned. In particular, certain developments in information theory suggested revolutions in the human way of life even more profound than those which atomic energy is already introducing, and I wished to incorporate these into the book I had attempted, but so far failed, to write.

A sea voyage from England to Australia gave an opportunity of getting to grips with the uncompleted job, which was finished just before I set out to the Great Barrier Reef. The knowledge that I was to spend some months diving among sharks of doubtful docility was an additional spur to action. It may or may not be true, as Doctor Johnson stated, that nothing settles a man’s mind so much as the knowledge that he will be hanged in the morning, but for my part I can testify that the thought of not returning from the Reef was the main reason why the book was completed at that particular time, and the ghost that had haunted me for almost twenty years was finally exorcised.

About a quarter of the present work appeared in Against the Fall of Night; it is my belief, however, that even those who read the earlier book will find that this is virtually a new novel. If not, at least I hope they will grant an author the right to have second thoughts. I promise them that this is my last word on the immortal city of Diaspar, in the long twilight of Earth.

Arthur C. Clarke

London, September, 1954

S.S. Himalaya—Sydney, March, 1955

Like a glowing jewel, the city lay upon the breast of the desert. Once it had known change and alteration, but now Time passed it by. Night and day fled across the desert’s face, but in the streets of Diaspar it was always afternoon, and darkness never came. The long winter nights might dust the desert with frost, as the last moisture left in the thin air of Earth congealed-but the city knew neither heat nor cold. It had no contact with the outer world; it was a universe itself.

Men had built cities before, but never a city such as this. Some had lasted for centuries, some for millenniums, before Time had swept away even their names. Diaspar alone had challenged Eternity, defending itself and all it sheltered against the slow attrition of the ages, the ravages of decay, and the corruption of rust.

Since the city was built, the oceans of Earth had passed away and the desert had encompassed all the globe. The last mountains had been ground to dust by the winds and the rain, and the world was too weary to bring forth more. The city did not care; Earth itself could crumble and Diaspar would still protect the children of its makers, bearing them and their treasures safely down the stream of time.

They had forgotten much, but they did not know it. They were as perfectly fitted to their environment as it was to them -for both had been designed together. What was beyond the walls of the city was no concern of theirs; it was something that had been shut out of their minds. Diaspar was all that existed, all that they needed, all that they could imagine. It mattered nothing to them that Man had once possessed the stars.

Yet sometimes the ancient myths rose up to haunt them, and they stirred uneasily as they remembered the legends of the Empire, when Diaspar was young and drew its lifeblood from the commerce of many suns. They did not wish to bring back the old days, for they were content in their eternal autumn. The glories of the Empire belonged to the past, and could remain there-for they remembered how the Empire had met its end, and at the thought of the Invaders the chill of space itself came seeping into their bones.

Then they would turn once more to the life and warmth of the city, to the long golden age whose beginning was already lost and whose end was yet more distant. Other men had dreamed of such an age, but they alone had achieved it.

They had lived in the same city, had walked the same miraculously unchanging streets, while more than a billion years had worn away.

It had taken them many hours to fight their way out of the Cave of the White Worms. Even now, they could not be sure that some of the pallid monsters were not pursuing them -and the power of their weapons was almost exhausted. Ahead, the floating arrow of light that had been their mysterious guide through the labyrinths of the Crystal Mountain still beckoned them on. They had no choice but to follow it, though as it had done so many times before it might lead them into yet more frightful dangers.

Alvin glanced back to see if all his companions were still with him. Alystra was close behind, carrying the sphere of cold but ever-burning light that had revealed such horrors and such beauty since their adventure had begun. The pale white radiance flooded the narrow corridor and splashed from the glittering walls; while its power lasted, they could see where they were going and could detect the presence of any visible dangers. But the greatest dangers in these caves, Alvin knew too well, were not the visible ones at all.

Behind Alystra, struggling with the weight of their projectors, came Narrillian and Floranus. Alvin wondered briefly why tose projectors were so heavy, since it would have been such a simple matter to provide them with gravity neutralizers. He was always thinking of points like this, even in the midst of the most desperate adventures. When such thoughts crossed his mind, it seemed as if the structure of reality trembled for an instant, and that behind the world of the senses he caught a glimpse of another and totally different universe…

The corridor ended in a blank wall. Had the arrow betrayed them again? No-even as they approached, the rock began to crumble into dust. Through the wall pierced a spinning metal spear, which broadened rapidly into a giant screw. Alvin and his friends moved back, waiting for the machine to force its way into the cave. With a deafening screech of metal upon rock-which surely must echo through all the recesses of the Mountain, and waken all its nightmare brood!-the subterrene smashed through the wall and came to rest beside them. A massive door opened, and Callistron appeared, shouting to them to hurry. («Why Callistron?» wondered Alvin. «Whats he doing here?») A moment later they were in safety, and the machine lurched forward as it began its journey through the depths of the earth.

The adventure was over. Soon, as always happened, they would be home, and all the wonder, the terror, and the excitement would be behind them. They were tired and content.

Alvin could tell from the tilt of the floor that the subterrene was heading down into the earth. Presumably Callistron knew what he was doing, and this was the way that led to home. Yet it seemed a pity…

«Callistron,» he said suddenly, «why don’t we go upward? No one knows what the Crystal Mountain really looks like. How wonderful it would be to come out somewhere on its slopes, to see the sky and all the land around it. We’ve been underground long enough.»