The light came flooding back into the room and the luminous rectangle upon which Alvin had projected his dreams merged into its surroundings, to become one with the other walls. But were they walls? To anyone who had never seen such a place before, this was a very peculiar room indeed. It was utterly featureless and completely devoid of furniture, so that it seemed as if Alvin stood at the center of a sphere. No visible dividing lines separated walls from floor or ceiling. There was nothing on which the eye could focus; the space enclosing Alvin might have been ten feet or ten miles across, for all that the sense of vision could have told. It would have been hard to resist the temptation to walk forward, hands outstretched, to discover the physical limits of this extraordinary place.

Yet such rooms had been «home» to most of the human race for the greater part of its history. Alvin had only to frame the appropriate thought, and the walls would become windows opening upon any part of the city he chose. Another wish, and machines which he had never seen would fill the chamber with the projected images of any articles of furniture he might need. Whether they were «real» or not was a problem that had bothered few men for the last billion years. Certainly they were no less real than that other impostor, solid matter, and when they were no longer required they could be returned to the phantom world of the city’s Memory Banks. Like everything else in Diaspar, they would never wear out-and they would never change, unless their stored patterns were canceled by a deliberate act of will.

Alvin had partly reconstructed his room when a persistent, bell-like chime sounded in his ear. He mentally framed the admission signal, and the wall upon which he had just been painting dissolved once more. As he bad expected, there stood his parents, with Jeserac a little behind them. The presence of his tutor meant that this was no ordinary family reunion -but he knew that already….