"This man Boyce," said Karellen. "Tell me all about him."

The Supervisor did not use those actual words, of course, and the thoughts he really expressed were far more subtle. A human listener would have heard a short burst of rapidly modulated sound, not unlike a high-speed Morse sender in action. Though many samples of Overlord language had been recorded, they all defied analysis because of their extreme complexity. The speed of transmission made it certain that no interpreter, even if he had mastered the elements of the language, could ever keep up with the Overlords in their normal conversation.

The Supervisor for Earth stood with his back to Rashaverak, staring out across the multicoloured gulf of the Grand Canyon. Ten kilometres away, yet scarcely veiled by distance, the terraced walls were catching the full force of the sun. Hundreds of metres down the shadowed slope at whose brim Karellen stood, a mule-train was slowly winding its way into the valley's depths. It was strange, Karellen thought, that so many human beings still seized every opportunity for primitive behaviour. They could reach the bottom of the canyon in a fraction of the time, and in far greater comfort, if they chose. Yet they preferred to be jolted along tracks which were probably as unsafe as they looked.

"Rupert Boyce is a somewhat curious character," Rashaverak answered. "Professionally, he's in charge of animal welfare over an important section of the main African reservation. He's quite efficient, and interested in his work. Because he has to keep watch over several thousand square kilometres, he has one of the fifteen panoramic viewers we've so far issued on loan -- with the usual safeguards, of course. It is, incidentally, the only one with full projection facilities. He was able to make a good case for these, so we let him have them."

Karellen made an imperceptible gesture with his hand. The great panorama faded from view, leaving only a shadowy blankness of indeterminable depth. The realities of his office and of his position crowded in upon the Supervisor once more.

"He wanted to appear to various wild animals so that they could get used to seeing him, and so wouldn't attack when he was physically present. The theory has worked out quite well with animals that rely on sight rather than smell -- though he'll probably get killed eventually. And, of course, there was another reason why we let him have the apparatus."

"What was his argument?"

"It made him more co-operative?"

"And what is Boyce's attitude to all this?"

"Precisely. I originally contacted him because he has one of the world's finest libraries of books on parapsychology and allied subjects. He politely but firmly refused to lend any of them, so there was nothing to do but to visit him. I've now read about half his library. It has been a considerable ordeal."

"Yes -- eleven clear cases of partial breakthrough, and twenty-seven probables. The material is so selective, however, that one cannot use it for sampling purposes. And the evidence is hopelessly confused with mysticism -- perhaps the prime aberration of the human mind."

"That I can well believe," said Karellen dryly. "Have you discovered anything among all the rubbish?"

"He pretends to be open-minded and skeptical, but it's clear that he would never have spent so much time and effort in this field unless he had some subconscious faith. I challenged him on this and he admitted that I was probably right. He would like to find some convincing proof. That is why he Is always carrying out these experiments, even though he pretends that they are only games."

"I see. And what about the girl who fainted?"

"You are sure he doesn't suspect that your interest is more than academic?"

"It was chance that brought him there -- his sister has just married Rupert Boyce. He had never met any of the other guests before. I am sure the question was unpremeditated, being inspired by the unusual conditions -- and probably by my presence. Given these factors, it is hardly surprising that he acted in the way he did. His great interest is astronautics: he is secretary of the space-travel group at Cape Town University, and obviously intends to make this field his life study."

"Quite sure. In many ways Boyce is remarkably obtuse and simple-minded. That makes his attempts to do research in this, of all fields, rather pathetic. There is no need to take any special action regarding him."

"This is the most exciting feature of the entire affair. Jean Morrel was, almost certainly, the channel through which the information came. But she is twenty-six -- far too old to be a prime contact herself, judging by all our previous experience. It must, therefore, be someone closely linked to her. The conclusion is obvious. We cannot have many more years to wait. We must transfer her to Category Purple: she may be the most important human being alive."

"I will do that. And what of the young man who asked the question? Was it random curiosity, or did he have some other motive?"

"I agree. Rodricks will have some information which is of doubtful truth, and of no practical value."

"His career should be interesting. Meanwhile, what action do you think he will take, and what shall we do about him?"

"I will have both situations evaluated," Karellen replied. "Though it is part of our Directive not to reveal our base, there is no way in which the information could be used against us."

"He will undoubtedly make some checks as soon as he can. But there is no way in which he can prove the accuracy of his information, and because of its peculiar origin he is hardly likely to publish it. Even if he does, will it affect matters in the slightest?"

"So it would seem," said Karellen. "But let us not be too certain. Human beings are remarkably ingenious, and often very persistent. It is never safe to underrate them, and it will be interesting to follow Mr. Rodricks' career. I must think about this further."

Rupert Boyce never really got to the bottom of it. When his guests had departed, rather less boisterously than usual, he had thoughtfully rolled the table back into its corner. The mild alcoholic fog prevented any profound analysis of what had happened, and even the actual facts were already slightly blurred. He had a vague idea that something of great but elusive importance had happened, and wondered if he should discuss it with Rashaverak. On second thought, he decided it aught be tactless. After all, his brother-in-law had caused the trouble, and Rupert felt vaguely annoyed with young Jan. But was it Jan's fault? Was it anybody's fault? Rather guiltily, Rupert remembered that it had been his experiment. He decided, fairly successfully, to forget the whole business.

The person most immediately affected had been George Greggson. He could never forget his feeling of terror as Jean pitched into his arms. Her sudden helplessness transformed her in that moment from an amusing companion to an object of tenderness and affection. Women had fainted -- not always without forethought -- since time immemorial, and men had invariably responded in the desired way. Jean's collapse was completely spontaneous, but it could not have been better planned. In that instant, as he realized later, George came to one of the most important decisions of his life. Jean was definitely the girl who mattered, despite her queer ideas and queerer friends. He had no intention of totally abandoning Naomi or Joy or Elsa or -- what was her name? -- Denise; but the time had come for something more permanent. He had no doubt that Jean would agree with him, for her feelings had been quite obvious from the start. Behind his decision there was another factor of which, he was unaware. Tonight's experience had weakened his contempt and skepticism for Jean's peculiar interests. He would never recognize the fact, but it was so -- and it had removed the last barrier between them.

Perhaps he might have done something if the last page of Ruth's notebook could have been found, but it had vanished in the confusion. Jan always feigned innocence -- and, well, one could hardly accuse Rashaverak. And no one could ever remember exactly what had been spelled out, except that it didn't seem to make any sense.

"Just let me restore the circulation," she pleaded, rubbing her fingers. "I wish you'd believe me when I tell you I'm perfectly all right now."

Jean smiled back at him and gently dislodged her hand from his.

"Then what do you think happened? Surely you remember something?"

He looked at Jean as she lay, pale but composed, in the reclining chair of the flyer. There was darkness below, stars above. George had no idea, to within a thousand kilometres, where they might be -- nor did he care. That was the business of the robot that was guiding them homewards and would land them in, so the control board announced, fifty-seven minutes from now.

She paused, then decided not to tell George that this sort of thing had happened before. She knew how he felt about these matters, and had no desire to upset him further -- and perhaps scare him away completely.

"No -- it's just a complete blank. I heard Jan ask his question -- and then you were all making a fuss over me. I'm sure it was some kind of trance. After all --"

"Oh, nothing. I wonder what that Overlord thought about the whole business. We probably gave him more material than he bargained for."

"After all -- what?" asked George.

Jean shivered slightly, and her eyes clouded.

George shifted uncomfortably.

"I'm afraid of the Overlords, George. Oh, I don't mean they're evil, or anything foolish like that. I'm sure they mean well and are doing what they think is best for us. I wonder just what their plans really are?"

"Men have been wondering that ever since they came to Earth," he said. "They'll tell us when we're ready for it -- and, frankly, I'm not inquisitive. Besides, I've got more important things to bother about." He turned towards Jean and grasped her hands.

"What about going to Archives tomorrow and signing a contract for -- let's say -- five years?"

Jean looked at him steadfastly, and decided that, on the whole, she liked what she saw.

Jan bided his time. There was no hurry, and he wanted to think. It was almost as if he feared to make any checks, lest the fantastic hope that had come into his mind be too swiftly destroyed. While he was still uncertain, he could at least dream.

"Make it ten," she said.

Moreover, to take any further action he would have to see the Observatory librarian. She knew him and his interests too well, and would certainly be intrigued by his request. Probably it would make no difference, but Jan was determined to leave nothing to chance. There would be a better opportunity in a week. He was being super-cautious, he knew, but that added a schoolboy zest to the enterprise. Jan also feared ridicule quite as much as anything that the Overlords might conceivably do to thwart him. If he was embarking on a wild-goose chase, no one else would ever know.

He had a perfectly good reason for going to London; the arrangements had been made weeks ago. Though he way too young and too unqualified to be a delegate, he was one of the three students who had managed to attach themselves to the official party going to the meeting of the International Astronomical Union. The vacancies had been there, and it seemed a pity to waste the opportunity, as he had not visited London since his childhood. He knew that very few of the dozens of papers to be delivered to the I. A. U. would be of the slightest interest to him, even if he could understand them. Like a delegate to any scientific congress, he would attend the lectures that looked promising, and spend the rest of the time talking with fellow enthusiasts, or simply sightseeing.

London had changed enormously in the last fifty years. It now contained scarcely two million people, and a hundred times as many machines. It was no longer a great port, for with every country producing almost all its needs, the entire pattern of world trade had been altered. There were some goods that certain countries still made best, but they went directly by air to their destinations. The trade routes that had once converged on the great harbours, and later on the great airports, had finally dispersed into an intricate web-work covering the whole world with no major nodal points.

Yet some things had not altered. The city was still a centre of administration, of art, of learning. In these matters, none of the continental capitals could rival it -- not even Paris, despite many claims to the contrary. A Londoner from a century before could still have found his way around, at least at the city's centre, with no difficulty. There were new bridges over the Thames, but in the old places. The great, grimy railway stations had gone -- banished to the suburbs. But the Houses of Parliament were unchanged; Nelson's solitary eye still stared down Whitehall; the dome of St. Paul's still stood above Ludgate Hill, though now there were taller buildings to challenge its preeminence. And the guard still marched in front of Buckingham Palace.

All these things, thought Jan, could wait. It was vacation time, and he was lodged, with his two fellow students, in one of the University hostels. Bloomsbury also had not changed its character in the last century: it was still an island of hotels and boarding-houses, though they no longer jostled each other so closely, or formed such endless, identical rows of soot-coated brick.

It was not until the second day of the Congress that Jan got his opportunity. The main papers were being read in the great assembly chamber of the Science Centre, not far from the Concert Hall that had done so much to make London the musical metropolis of the world. Jan wanted to hear the first of the day's lectures, which, it was rumoured, would completely demolish the current theory of the formation of the planets.

Some humorous civil servant had put the Royal Astronomical Society on the top floor of the great building, a gesture which the Council members fully appreciated as it gave them a magnificent view across the Thames and over the entire northern part of the city. There seemed to be nobody around, but Jan -- clutching his membership card like a passport in case he was challenged -- had no difficulty in locating the library.

Perhaps it did, but Jan was little the wiser when he left after the interval. He hurried down to the directory, and looked up the rooms he wanted.

He put the catalogue back among its fellows, and for a long time sat quite still, staring sightlessly at the wall of volumes before him. Then he slowly walked out into the still corridors, past the secretary's office (there was somebody there now, busily unpacking parcels of books) and down the stairs. He avoided the elevator, for he wanted to be free and unconfined. There was another lecture he had intended to hear, but that was no longer important now.

It took him almost an hour to find what he wanted, and to learn how to handle the great star catalogues with their millions of entries. He was trembling slightly as he neared the end of his quest, and felt glad that there was no one around to see his nervousness.

His thoughts were still in turmoil as he crossed to the embankment wall and let his eye follow the Thames on its unhurried way to the sea. It was hard for anyone with his training in orthodox science to accept the evidence that had now come into his hands. He would never be certain of its truth, yet the probability was overwhelming. As he paced slowly beside the river wall, he marshaled the facts one by one.

Fact two: "NGS 549672" probably meant nothing to anyone except an astronomer. Though the great National Geographic Survey had been completed half a century before, its existence was known only to a few thousand specialists. And taking any number from it at random, no one could have said where that particular star lay in the heavens.

Fact one: no one at Rupert's party could possibly have known that he was going to ask that question. He had not known it himself: it had been a spontaneous reaction to the circumstances. Therefore, no one could have prepared any answer, or had it already lying in their minds.

But -- and this was Fact three, which he had only this moment discovered -- the small and insignificant star known as NGS 549672 was in precisely the right place. It lay in the heart of the constellation Carina, at the end of that shining trail Jan himseLf had seen, so few nights ago, leading from the Solar System out across the depths of space.

It was an impossible coincidence. NGS 549672 must be the home of the Overlords. Yet to accept the fact violated all Jan's cherished ideas of scientific method. Very well -- let them be violated. He must accept the fact that, somehow, Rupert's fantastic experiment had tapped a hitherto unknown source of knowledge.

Rashaverak? That seemed the most probable explanation. The Overlord had not been in the circle, but that was a minor point. However, Jan was not concerned with the mechanism of paraphysics: he was only interested in using the results.

A slow smile spread over Jan's face as he turned away from the Thames, back towards the gleaming white facade of the Science Centre. Knowledge was power -- and he was the only man on Earth who knew the origin of the Overlords. How he would use that knowledge he could not guess. It would lie safely in his mind, awaiting the moment of destiny.

Very little was know about NGS 549672: there had been nothing to distinguish it from a million other stars. But the catalogue gave its magnitude, its co-ordinates, and its spectral type. Jan would have to do a little research, and make a few simple calculations: then he would know, at least approximately, how far the world of the Overlords was from Earth.