On rare and unforeseeable occasions, the Jester would turn the city upside-down by some prank which might be no more than an elaborate practical joke, or which might be a calculated assault on some currently cherished belief or way of life. All things considered, the name «Jester» was a highly appropriate one. There had once been men with very similar duties, operating with the same license, in the days when there were courts and kings.

«It will help,» said Jeserac, «if we are frank with one another. We both know that Alvin is a Unique that he has never experienced any earlier life in Diaspar. Perhaps you can guess, better than I can, the implications of that. I doubt if anything that happens in the city is totally unplanned, so there must be a purpose in his creation. Whether he will achieve that purpose-whatever it is-I do not know. Nor do I know whether it is good or bad. I cannot guess what it is.»

«Suppose it concerns something external to the city?»

Jeserac smiled patiently; the Jester was having his little joke, as was only to be expected.

«I have told him what lies there; he knows that there is nothing outside Diaspar except the desert. Take him there if you can; perhaps you know a way. When he sees the reality, it may cure the strangeness in his mind.»

«I think be has already seen it,» said Khedron softly. But he said it to himself, and not to Jeserac.

«I do not believe that Alvin is happy,» Jeserac continued. «He has formed no real attachments, and it is hard to see how he can while he still suffers from this obsession. But after all, he is very young. He may grow out of this phase, and become part of the pattern of the city.»

Jeserac was talking to reassure himself; Khedron wondered if he really believed what he was saying.

«Tell me, Jeserac,» asked Khedron abruptly, «does Alvin know that be is not the first Unique?»

Jeserac looked startled, then a little defiant.

«I might have guessed,» he said ruefully, «that you would know that. How many Uniques have there been in the whole history of Diaspar? As many as ten?»

«Fourteen,» answered Khedron without hesitation. «Not counting Alvin.»

«You have better information than I can command,» said Jeserac wryly. «Perhaps you can tell me what happened to those Uniques?»

«They disappeared.»

«Thank you: I knew that already. That is why I have told Alvin as little as possible about his predecessors: it would hardly help him in his present mood. Can I rely on your co-operation?»

«For the moment-yes. I want to study him myself; mysteries have always intrigued me, and there are too few in Diaspar. Besides, I think that Fate may be arranging a jest beside which all my efforts will look very modest indeed. In that case, I want to make sure that I am present at its climax.»

«You are rather too fond of talking in riddles,» complained Jeserac. «Exactly what are you anticipating?»

«I doubt if my guesses will be any better than yours. But I believe this-neither you nor I nor anyone in Diaspar will be able to stop Alvin when he has decided what he wants to do. We have a very interesting few centuries ahead of us.»

Jeserac sat motionless for a long time, his mathematics forgotten, after the image of Khedron had faded from sight. A sense of foreboding, the like of which he had never known before, hung heavily upon him. For a fleeting moment he wondered if be should request an audience with the Council -but would that not be making a ridiculous fuss about noth-ing? Perhaps the whole affair was some complicated and ob-scure jest of Khedron’s, though he could not imagine why he had been chosen to be its butt.

He thought the matter over carefully, examining the prob-lem from every angle. After little more than an hour, he made a characteristic decision.

He would wait and see.

Alvin wasted no time learning all that he could about Khedron. Jeserac, as usual, was his main source of information. The old tutor gave a carefully factual account of his meeting with the Jester, and added what little he knew about the other’s mode of life. Insofar as such a thing was possible in Diaspar, Khedron was a recluse: no one knew where he lived or anything about his way of life. The last jest he had contrived had been a rather childish prank involving a general paralysis of the moving ways. That had been fifty years ago; a century earlier he had let loose a particularly revolting dragon which had wandered around the city eating every existing specimen of the works of the currently most popular sculptor. The artist himself, justifiably alarmed when the beast’s single-minded diet became obvious, had gone into hiding and not emerged until the monster had vanished as mysteriously as it had appeared.

One thing was obvious from these accounts. Khedron must have a profound understanding of the machines and powers that ruled the city, and could make them obey his will in ways which no one else could do. Presumably there must be some overriding control which prevented any too-ambitious Jester from causing permanent and irreparable damage to the complex structure of Diaspar.

Alvin filed all this information away, but made no move to contact Khedron. Though he had many questions to ask the Jester, his stubborn streak of independence-perhaps the most truly unique of all his qualities-made him determined to discover all he could by his own unaided efforts. He had embarked on a project that might keep him busy for years, but as long as he felt that he was moving toward his goal he was happy.

Like some traveler of old mapping out an unknown land, he had begun the systematic exploration of Diaspar. He spent his weeks and days prowling through the lonely towers at the margin of the city, m the hope that somewhere he might dis-cover a way out into the world beyond. During the course of his search he found a dozen of the great air vents opening high above the desert, but they were all barred-and even if the bars had not been there, the sheer drop of almost a mile was sufficient obstacle.

He found no other exits, though he explored a thousand corridors and ten thousand empty chambers. All these buildings were in that perfect and spotless condition which the people of Diaspar took for granted as part of the normal order of things. Sometimes Alvin would meet a wandering robot, obviously on a tour of inspection, and he never failed to question the machine. He learned nothing, because the machines he encountered were not keyed to respond to human speech or thoughts. Though they were aware of his presence, for they floated politely aside to let him pass, they refused to engage in conversation.

There were times when Alvin did not see another human being for days. When he felt hungry, he would go into one of the living apartments and order a meal. Miraculous machines to whose existence he seldom gave a thought would wake to life after aeons of slumber. The patterns they had stored in their memories would flicker on the edge of reality, organizing and directing the matter they controlled. And so a meal prepared by a master chef a hundred million years before would be called again into existence to delight the palate or merely to satisfy the appetite.

The loneliness of this deserted world-the empty shell sur-rounding the living heart of the city-did not depress Alvin. He was used to loneliness, even when he was among those he called his friends. This ardent exploration, absorbing all his energy and interest, made him forget for the moment the mystery of his heritage and the anomaly that cut him off from all his fellows.

He had explored less than one-hundredth of the city’s rim when he deeded that he was wasting his time. His decision was not the result of impatience, but of sheer common sense. If needs be, he was prepared to come back and finish the task, even if it took him the remainder of his life. He had seen enough, however, to convince him that if a way out of Diaspar did exist, it would not be found as easily as this. He might waste centuries in fruitless search unless he called upon the assistance of wiser men.