Sim cried steadily. Everywhere he looked was horror. A mind came to meet his own. Instinctively he glanced toward the stone crib. Dark, his sister, returned his glance. Their minds brushed like straying fingers. He relaxed somewhat. He began to learn. The father sighed, shut his lids down over his green eyes. "Feed the child," he said, exhaustedly. "Hurry. It is almost dawn and it is our last day of living, woman. Feed him. Make him grow." Sim quieted, and images, out of the terror, floated to him. This was a planet next to the sun. The nights burned with cold, the days were like torches of fire. It was a violent, impossible world. The people lived in the cliffs to escape the incredible ice and the day of flame. Only at dawn and sunset was the air breath-sweet, flower-strong, and then the cave peoples brought their children out into a stony, barren valley. At dawn the ice thawed into creeks and rivers, at sunset the day-fires died and cooled. In the intervals of even, livable temperature the people lived, ran, played, loved, free of the caverns; all life on the planet jumped, burst into life. Plants grew instantly, birds were flung like pellets across the sky. Smaller, legged animal life rushed frantically through the rocks; everything tried to get its living down in the brief hour of respite. It was an unbearable planet. Sim understood this, a matter of hours after birth. Racial memory bloomed in him. He would live his entire life in the caves, with two hours a day outside. Here, in stone channels of air he would talk, talk incessantly with his people, sleep never, think, think and lie upon his back, dreaming; but never sleeping. And he would live exactly eight days. The violence of this thought evacuated his bowels. Eight days. Eight short days. It was wrong, impossible, but a fact. Even while in his mother's flesh some racial knowledge had told him he was being formed rapidly, shaped and propelled out swiftly. Birth was quick as a knife. Childhood was over in a flash. Adolescence was a sheet of lightning. Manhood was a dream, maturity a myth, old age an inescapably quick reality, death a swift certainty. Eight days from now he'd stand half-blind, withering, dying, as his father now stood, staring uselessly at his own wife and child. This day was an eighth part of his total life! He must enjoy every second of it. He must