''And precisely why are you going to close the way to Lys?^^

             It was some time before Rorden's mind, unwilling to recognize disaster, would admit that it was Alvin who spoke.

             The success of his subterfuge had given Alvin only a moment's satisfaction. Throughout the President's address his anger had been steadily rising as he realized that, despite all his cleverness, his plans were to be thwarted. The feelings he had known in Lys when Seranis had presented her ultimatum came back with redoubled strength. He had won that contest, and the taste of power was still sweet.

             This time he had no robot to help him, and he did not know what the outcome would be. But he no longer had any fear of these foolish old men who thought themselves the rulers of Diaspar. He had seen the real rulers of the city, and had spoken to them in the grave silence of their brilliant, buried world. So in his anger and arrogance, Alvin threw away his disguise and the councillors looked in vain for the artless boy who had addressed them a little while ago.

             ''Why are you going to close the way to Lys?''

             There was silence in the Council Room, but the lips of Jeserac twisted into a slow, secret smile. This Alvin was new to him, but it was less alien than the one who had spoken before.

             The President chose at first to ignore the challenge. Perhaps he could not bring himself to believe that it was more than an innocent question, however violently it had been expressed.

             "That is a matter of high policy which we cannot discuss here," he said pompously, "but Diaspar cannot risk contamination with other cultures." He gave Alvin a benevolent but slightly worried smile.

             "It's rather strange," said Alvin coldly, "that in Lys I was told exactly the same thing about Diaspar." He was glad to see the start of annoyance, but gave his audience no time to reply.

             "Lys," he continued, "is much larger than Diaspar and its cuhure is certainly not inferior. It's always known about us but has chosen not to reveal itself—as you put it, to avoid contamination. Isn't it obvious that we are both wrong?"

             He looked expectantly along the lines of faces, but nowhere was there any understanding of his words. Suddenly his anger against these leaden-eyed old men rose to a crescendo. The blood was throbbing in his cheeks, and though his voice was steadier now it held a note of icy contempt which even the most pacific of the councillors could no longer overlook.

             "Our ancestors," began Alvin, "built an empire which reached to the stars. Men came and went at will among all those worlds—and now their descendants are afraid to stir beyond the walls of their city. Shall I tell you why?'''' He paused: there was no movement at all in the great bare room.

             "It is because we are afraid—afraid of something that happened at the beginning of history. I was told the truth in Lys, though I had guessed it long ago. Must we always hide like cowards in Diaspar, pretending that nothing else exists—because half a billion years ago the Invaders drove us back to Earth?"

             He had put his finger on their secret fear, the fear that he had never shared and whose power he could therefore never understand. Let them do what they pleased: he had spoken the truth.

             His anger drained away and he was himself again, as yet only a little alarmed at what he had done. He turned to the President in a last gesture of independence.

             "Have I your permission to leave?"

             Still no words were spoken, but the slight inclination of the head gave him his release. The great doors expanded before him and not until long after they had closed again did the storm break upon the Council Chamber.

             The President waited until the inevitable lull. Then he turned to Jeserac.

             "It seems to me," he said, "that we should hear your views first."

             Jeserac examined the remark for possible traps. Then he replied:

             "I think that Diaspar is now losing its most outstanding brain."

             "What do you mean?"

             "Isn't it obvious? By now young Alvin will be halfway to the Tomb of Yarlan Zey. No, we shouldn't interfere. I shall be very sorry to lose him, though he never cared very much for me." He sighed a little. "For that matter, he never cared a great deal for anyone save Alvin of Loronei."

             .

12.

             Not until an hour later was Rorden able to escape from the Council Chamber. The delay was maddening, and when he reached his rooms he knew it was too late. He paused at the entrance, wondering if Alvin had left any message, and realizing for the first time how empty the years ahead would be.

             The message was there, but its contents were totally unexpected. Even when Rorden had read it several times, he was still completely baffled:

             "Meet me at once in the Tower of Loranne."

             Only once before had he been to the Tower of Loranne, when Alvin had dragged him there to watch the sunset. That was years ago: the experience had been unforgettable but the shadow of night sweeping across the desert had terrified him so much that he had fled, pursued by Alvin's entreaties. He had sworn that he would never go there again. . . .

             Yet here he was, in that bleak chamber pierced with the horizontal ventilating shafts. There was no sign of Alvin, but when he called, the boy's voice answered at once.

             "I'm on the parapet—come through the center shaft."

             Rorden hesitated: there were many things he would much rather do. But a moment later he was standing beside Alvin with his back to the city and the desert stretching endlessly before him.

             They looked at each other in silence for a little while. Then Alvin said, rather contritely:

             "I hope I didn't get you into trouble."

             Rorden was touched, and many truths he was about to utter died abruptly on his lips. Instead he replied:

             "The Council was too busy arguing with itself to bother about me." He chuckled. "Jeserac was putting up quite a spirited defense when I left. I'm afraid I misjudged him."

             "I'm sorry about Jeserac."

             "Perhaps it was an unkind trick to play on the old man, but I think he's rather enjoying himself. After all, there was some truth in your remark. He was the first man to show you the ancient world, and he has rather a guilty conscience."

             For the first time, Alvin smiled.

             "It's strange," he said, "but until I lost my temper I never really understood what I wanted to do. Whether they like it or not, I'm going to break down the wall between Diaspar and Lys. But that can wait: it's no longer so important now."

             Rorden felt a little alarmed.

             "What do you mean?" he asked anxiously. For the first time he noticed that only one of the robots was with them on the parapet. "Where's the second machine?"

             Slowly Alvin raised his arm and pointed out across the desert, towards the broken hills and the long line of sand dunes, crisscrossed like frozen waves. Far away, Rorden could see the unmistakable gleam of sunlight upon metal.

             "We've been waiting for you," said Alvin quietly. "As soon as I left the Council, I went straight to the robots. Whatever happened, I was going to make sure that no one took them away before I'd learned all they could teach me. It didn't take long, for they're not very intelligent and knew less than I'd hoped. But I have found the secret of the Master. " He paused for a moment, then pointed again at the almost invisible robot. "Watch!"