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. Few things grew here, since the rain came only in the first months of spring and sparsely even then. In the dry washes there were lumpish plants with prosaic names: barrel cucumbers, leather vines. In the courtyard of the compound a native garden had been planted, cactus feathery with purple flowers, tall nevergreens with weblike blossoms that extracted moisture from the air. Sometimes a man named Raj irrigated the garden from a pump that ran deep into the earth, and on those mornings the air smelled of mineral-rich water: a steely scent that carried for kilometers. On watering day, rock shrews would burrow under the fence and tumble comically across the tiled courtyard.

Isaac's days passed in gentle sameness early in the summer of his twelfth year, as his days had always passed, but that sleepy peace came to an end the day the old woman arrived.

* * * * *

She came, remarkably, on foot.

Isaac had left the compound that afternoon and climbed a small distance up the foothills, to a granite shelf that jutted from the slope of a ridge like a ship's prow from a pebbly sea. The afternoon sun had warmed the rock to a fine, fierce heat. Isaac, with his wide-brimmed hat and white cotton shirt to protect him from the burning light, sat under the lip of the ridge where there was still shade, watching the horizon. The desert rippled in rising waves of furnace air. He was alone and motionless—afloat in heat, a castaway on a sere raft of stone—when the woman appeared. At first she was just a dot down the unpaved road that led from the distant towns where Isaac's keepers went to buy food and supplies. She moved slowly, or seemed to. Nearly an hour passed before he could identify her as a woman—then an old woman—then an old woman with a pack on her back, a bow-legged posture, and a dogged, determined stride. She wore a white robe and a white sun hat.