In the summer of his twelfth year—the summer the stars began to fall from the sky—the boy Isaac discovered that he could tell east from west with his eyes closed.

Isaac lived at the edge of the Great Inland Desert, on the continent of Equatoria, on the planet that had been appended to the Earth by the inscrutable beings called the Hypotheticals. People had given the planet a whole panoply of grandiose or mythological or coolly scientific names, but most simply called it the New World, in any of a hundred or more languages, or Equatoria, after its most widely settled continent. These were things Isaac had learned in what passed for school.

He lived in a compound of brick and adobe, far from the nearest town. He was the only child at the settlement. The adults with whom he lived preferred to keep a careful distance between themselves and the rest of the world. They were special, in ways they were reluctant to discuss. Isaac, too, was special. They had told him so, many times. But he wasn't sure he believed them. He didn't feel special. Often he felt much less than special.

Occasionally the adults, especially Dr. Dvali or Mrs. Rebka, asked Isaac whether he was lonely. He wasn't. He had books, he had the video library to fill his time. He was a student, and he learned at his own pace—steadily if not quickly. In this, Isaac suspected, he was a disappointment to his keepers. But the books and videos and lessons filled his time, and when they were unavailable there was the natural world around him, which had become a kind of mute, indifferent friend: the mountains, gray and green and brown, sloping down to this arid plain, the edge of the desert hinterland, a curdled landscape of rock and sand.