"In the early days," said Karellen, "it was safe for us to go among them. But they no longer needed us: our work was done when we had gathered them together and given them a continent of their own. Watch."

"This will distress you," said Karellen. "But remember that your standards no longer apply. You are not watching human children."

"This is five years later, when the second phase had begun."

There were figures moving below, and the camera swooped down upon them like a bird of prey.

The wall in front of Jan disappeared. Instead he was looking down from a height of a few hundred metres on to a pleasantly wooded country. The illusion was so perfect that he fought a momentary giddiness.

Yet that was the immediate impression that came to Jan's mind, and no amount of logic could dispel it. They might have been savages, engaged in some complex ritual dance. They were naked and filthy, with matted hair obscuring their eyes. As far as Jan could tell, they were of all ages from five to fifteen, yet they all moved with the same speed, precision, and complete indifference to their surroundings.

"You are searching for something that is no longer there," said Karellen. "Remember -- they have no more identity than the cells in your own body. But linked together, they are something much greater than you."

Then Jan saw their faces. He swallowed hard, and forced himself not to turn away. They were emptier than the faces of the dead, for even a corpse has some record carved by time's chisel upon its features, to speak when the lips themselves are dumb. There was no more emotion or feeling here than in the face of a snake or an insect. The Overlords themselves were more human than this.

"Why do they keep moving like this?"

"We called it the Long Dance," replied Karellen. "They never sleep, you know, and this lasted almost a year. Three hundred million of them, moving in a controlled pattern over a whole continent. We've analyzed that pattern endlessly, but it means nothing, perhaps because we can see only the physical part of it -- the small portion that's here on Earth. Possibly what we have called the Overmind is still training them, moulding them into one unit before it can wholly absorb them into its being."

"Watch again," said Karellen. "It is three years later."

The scene flickered as if a heat haze had passed over it. When it cleared, the movement below had ceased.

"Water made no difference: they could not drown. When they encountered obstacles, they sometimes damaged themselves, but they never noticed it. As for food -- well, there was all the fruit and game they required. But now they have left that need behind, like so many others. For food is largely a source of energy, and they have learned to tap greater sources."

The little figures, so helpless and pathetic if one did not know the truth, stood motionless in forest and glade and plaint The camera roamed restlessly from one to the other: already, thought Jan, their faces were merging into a common mould. He had once seen some photographs made by the superposition of dozens of prints to give one "average" face. The result had been as empty, as void of character as this.

"But how did they manage about food? And what happened if they hit obstructions, like trees, or cliffs, or water?"

They seemed to be sleeping or entranced. Then eyes were tightly closed, and they showed no more awareness of their surroundings than did the trees under which they stood. What thoughts, Jan wondered, were echoing through the intricate network in which their minds were now no more -- and yet no less -- than the separate threads of some great tapestry? And a tapestry, he now realized, that covered many worlds and many races -- and was growing still.

It happened with a swiftness that dazzled the eye and stunned the brain. At one moment Jan was looking down upon a beautiful, fertile country with nothing strange about it save the countless small statues scattered -- yet not randomly -- over its length and breadth. And then in an instant all the trees and grass, all the living creatures that had inhabited this land, flickered out of existence and were gone. There were left only the still lakes, the winding rivers, the rolling brown hills, now stripped of their green carpet -- and the silent, indifferent figures who had wrought all this destruction.

"That was many years ago," said Jan. "What has happened since?"

"Perhaps the presence of other minds disturbed them -- even the rudimentary minds of plants and animals. One day, we believe, they may find the material world equally distracting. And then, who knows what will happen? Now you understand why we withdrew when we had done our duty. We are still trying to study them, but we never enter their land or even send our instruments there. All we dare do is to observe from space."

"Why did they do it?" gasped Jan.

"Yes, though that is not surprising. The-entity-of which they are part knows all about us. It does not seem to care if we attempt to study it. When it wishes us to leave, or has a new task for us elsewhere, it will make its desires very obvious. Until then, we will remain here so that our scientists can gather what knowledge they may."

"And they have ignored you completely?"

"Very little. They have never moved in all that time, and take no notice of day or night, summer or winter. They are still testing their powers; some rivers have changed their courses, and there is one that flows uphill. But they have done nothing that seems to have any purpose."

For the road to the stars was a road that forked in two directions, and neither led to a goal that took any account of human hopes or fears.

Yet it was fitting: it had the sublime inevitability of a great work of art. Jan had glimpsed the universe in all its awful immensity, and knew now that it was no place for man. He realized at last how vain, in the ultimate analysis, had been the dream that had lured him to the stars.

At the end of one path were the Overlords. They had preserved their individually, their independent egos; they possessed self-awareness and the pronoun "I" had a meaning in their language. They had emotions, some at least of which were shared by humanity. But they were trapped, Jan realized now, in a cul-de-sac from which they could never escape. Their minds were ten -- perhaps a hundred -- times as powerful as men's. It made no difference in the final reckoning. They were equally helpless, equally overwhelmed by the unimaginable complexity of a galaxy of a hundred thousand million suns, and a cosmos of a hundred thousand million galaxies.

So this, thought Jan, with a resignation that lay beyond all sadness, was the end of man. It was an end that no prophet had ever foreseen -- an end that repudiated optimism and pessimism alike.

He never learned the full story of the strange symbiosis between the Overmind and its servants. According to Rasha- verak, there had never been a time in his races history when the Overmind was not there, though it had made no use of them until they had achieved a scientific civilization and could range through space to do its bidding.

And at the end of the other path? There lay the Overmind, whatever it might be, bearing the same relation to man as man bore to amoeba. Potentially infinite, beyond mortality, how long had it been absorbing race after race as it spread across the stars? Did it too have desires, did it have goals it sensed dimly yet might never attain? Now it had drawn into its being all that the human race had ever achieved. This was not tragedy, but fulfillment. The billions of transient sparks of consciousness that had made up humanity would flicker no more like fireflies against the night. But they had not lived utterly in vain.

He understood their purpose now, what they had done with Man and why they still lingered upon Earth. Towards them he felt a great humility, as well as admiration for the inflexible patience that had kept them waiting here so long.

The last act, Jan knew, had still to come. It might occur tomorrow, or it might be centuries hence. Even the Overlords could not be certain.

"No," said Rashaverak, "it has limits. In the past, we know, it has attempted to act directly upon the minds of other races, and to influence their cultural development. It's always failed, perhaps because the gulf is too great. We are the interpreters -- the guardians. Or, to use one of your own metaphors, we till the field until the crop is ripe. The Overmind collects the harvest -- and we move on to another task. This is the fifth race whose apotheosis we have watched. Each time we learn a little more."

"And do you not resent being used as a tool by the Overmind?"

"The arrangement has some advantages: besides, no one of intelligence resents the inevitable."

"But why does it need you?" queried Jan. "With all its tremendous powers, surely it could do anything it pleased."

"It seems strange," said Jan, "that the Overmind chose you to do its work, if you have no trace of the paraphysical powers latent in mankind. How does it communicate with you and make its wishes known?"

That proposition, Jan reflected wryly, had never been fully accepted by mankind. There were things beyond logic that the Overlords had never understood.

Jan puzzled over this for a moment, but knew it was useless to follow this line of inquiry. He would have to change the subject and hope to pick up clues later.

"Tell me this, then," he said, "this is something else you've never explained. When your race first came to Earth, back in the distant past, what went wrong? Why had you become the symbol of fear and evil to us?"

Rashaverak smiled. He did not do this as well as Karellen could, but it was a fair imitation.

"What do you mean?" asked Jan.

"That is one question I cannot answer -- and I cannot tell you the reason why I must keep the facts from you. One day, perhaps, you will know some of the truth."

"No one ever guessed, and you see now why we could never tell you. There was only one event that could have made such an impact upon humanity. And that event was not at the dawn of history, but at its very end."

"When our ships entered your skies a century and a half ago, that was the first meeting of our two races, though of course we had studied you from a distance. And yet you feared and recognized us, as we knew that you would. It was not precisely a memory. You have already had proof that time is more complex than your science ever imagined. For that memory was not of the past, but of the future -- of those closing years when your race knew that everything was finished. We did what we could, but it was not an easy end. And because we were there, we became identified with your race's death. Yes, even while it was still ten thousand years in the future! It was as if a distorted echo had reverberated round the closed circle of time, from the future to the past. Call it not a memory, but a premonition."

There must be such a thing as racial memory, and that memory was somehow independent of time. To it, the future and the past were one. That was why, thousands of years ago, men had already glimpsed a distorted image of the Overlords, through a mist of fear and terror.

"Now I understand," said the last man.

The Last Man! Jan found it very hard to think of himself as that. When he had gone into space, he had accepted the possibility of eternal exile from the human race, and loneliness had not yet come upon him. As the years passed, the longing to see another human being might rise and overwhelm him, but for the present, the company of the Overlords prevented him from feeling utterly alone.

There had been men on Earth as little as ten years ago, but they had been degenerate survivors and Jan had lost nothing by missing them. For reasons which the Overlords could not explain, but which Jan suspected were largely psychological, there had been no children to replace those who had gone. Homo sapiens was extinct.

The idea was hard to grasp, and for a moment Jan wrestled with it in silence. Yet he should have been prepared; he had already received proof enough that cause and event could reverse their normal sequence.

Those who had not destroyed themselves had sought oblivion in ever more feverish activities, in fierce and suicidal sports that were often indistinguishable from minor wars. As the population had swiftly fallen, the aging survivors had clustered together, a defeated army closing its ranks as it made its last retreat.

Perhaps, lost in one of the still-intact cities, was the manuscript of some later-day Gibbon, recording the last days of the human race. If so, Jan was not sure that he would care to read it; Rashaverak had told him all that he wished to know.

There was plenty to occupy his mind. The Overlords' base was about a kilometre from a deserted villa, and Jan spent months fitting this out with equipment he had taken from the nearest town, some thirty kilometres distant. He had flown there with Rashaverak, whose friendship, he suspected, was not completely altruistic. The Overlord psychologist was still studying the last specimen of Homo sapiens.

That final act, before the curtain came down for ever, must have been lit by flashes of heroism and devotion, darkened by savagery and selfishness. Whether it had ended in despair or resignation, Jan would never know.

Often he would go for long walks on the hills, thinking of all that had happened in the few months since he had last seen Earth. He had never thought, when he said goodbye to Sullivan eighty terrestrial years ago, that the last generation of mankind was already in the womb.

There was everything here that he needed to maintain himself for the rest of his life, but what he wanted most was an electronic piano and certain Bach transcriptions. He had never had as much time for music as he would have liked, and now he would make up for it. When he was not performing himself, he played tapes of the great symphonies and concertos, so that the villa was never silent. Music had become his talisman against the loneliness which, one day, must surely overwhelm him.

The town must have been evacuated before the end, for the houses and even many of the public services were still in good order. It would have taken little work to restart the generators, so that the wide streets glowed once more with the illusion of life. Jan toyed with the idea, then abandoned it as too morbid. The one thing he did not wish to do was to brood upon the past.

What a young fool he had been! Yet he was not sure that he regretted his action; had he stayed on Earth, he would have witnessed those closing years over which time had now drawn a veil. Instead, he had leap-frogged past them into the future, and had learned the answers to questions that no other man would ever know. His curiosity was almost satisfied, but sometimes he wondered why the Overlords were waiting, and what would happen when their patience was at last rewarded.

Jan had always been a good pianist -- and now he was the finest in the world.

But most of the time, with a contented resignation that comes normally to a man only at the end of a long and busy life, he sat before the keyboard and filled the air with his beloved Bach. Perhaps he was deceiving himself, perhaps this was some merciful trick of the mind, but now it seemed to Jan that this was what he had always wished to do. His secret ambition had at last dared to emerge into the full light of consciousness.