“Jeserac,” said Alvin at last, “once I went to the Tower of Loranne. No one lives there any more, and I could look out over the desert. It was dark, and I couldn’t see the ground, but the sky was full of colored lights. I watched them for a long time, but they never moved. So presently I came away. Those were the stars, weren’t they?”

Jeserac was alarmed. Exactly how Alvin had got to the Tower of Loranne was a matter for further investigation. The boy’s interests were becoming-dangerous.

“Those were the stars,” he answered briefly. “What of them?”

“We used to visit them once, didn’t we?”

A long pause. Then, “Yes.”

“Why did we stop? What were the invaders?”

Jeserac rose to his feet. His answer echoed back through all the teachers the world had ever known.

“That’s enough for one day, Alvin. Later, when you are older, I’ll tell you more-but not now. You already know too much.”

Alvin never asked the question again: later, he had no need, for the answer was clear. And there was so much in Diaspar to beguile the mind that for months he could forget that strange yearning he alone seemed to feel.

Diaspar was a world in itself. Here Man had gathered all his treasures, everything that had been saved from the ruin of the past. All the cities that had ever been had given something to Diaspar: even before the coming of the Invaders its name had been known on the worlds that Man had lost.