Especially was it nightmare--after some centuries--for the descendants of the human beings from the space-liner _Icarus_, wrecked there some forty-odd generations ago. Naturally, nobody anywhere else thought of the _Icarus_ any more. It was not even remembered by the descendants of its human cargo, who now inhabited the planet. The wreckage of the ship was long since hidden under the seething, furiously striving fungi of the boil. The human beings on the planet had forgotten not only the ship but very nearly everything--how they came to this world, the use of metals, the existence of fire, and even the fact that there was such a thing as sunlight. They lived in the lowlands, deep under the cloud-bank, amid surroundings which were riotous, swarming, frenzied horror. They had become savages. They were less than savages. They had forgotten their high destiny as men. * * * * * [Illustration] Dawn came. Grayness appeared overhead and increased. That was all. The sky was a blank, colorless pall, merely mottled where the clouds clustered a little thicker or a little thinner, as clouds do. But the landscape was variegated enough! Where the little group of people huddled together, there was a wide valley. Its walls rose up and up into the very clouds. The people had never climbed those hillsides. They had not even traditions of what might lie above them, and their lives had been much too occupied to allow of speculations on cosmology. By day they were utterly absorbed in two problems which filled every waking minute. One was the securing of food to eat, under the conditions of the second problem, which was that of merely staying alive. There was only one of their number who sometimes thought of other matters, and he did so because he had become lost from his group of humans once, and had found his way back to it. His name was Burl, and his becoming lost was pure fantastic accident, and his utilization of a fully inherited power to think was the result of extraordinary events. But he still had not the actual habit of thinking. This morning he was like his fellows.