There was a field, some hills, a tiny frozen creek and the dark shapes of rounded mountains in the distance. All without color except for the cold, faint glow of the star that was the Sun. A thin layer of cosmic dust lay over the surface, such as would be found on any airless world. Russ scooped beneath it and came up with a hard chip. He squeezed it between his gauntleted fingers. It cracked and broke into powder. He whistled softly. "You know what this feels and looks like?" he said as they came close to the frozen creek on the little hillside. "It feels like dirt--common, Earthly dirt. Like soil. And you know what ... I can already tell you one of Pluto's secrets." They stopped at the creek. It was a layer of frozen crystalline gases. Haines pushed the alpenstock he was carrying into it and scraped away the gas crystals. "I think I can guess," he said, "and I'll bet there is ice under this gas." "Pluto was once a warm world with a thick atmosphere," said Russ. "Notice the rounded hills and the worn away peaks of the mountains. Those are old mountains--weather-beaten. This hill is round--weather-beaten. This creek, those rivers of frozen gas--they follow beds that could only be made by real rivers of warm water. The soil that lies beneath this dust--it could only happen on a world that knew night and day, warmth and light, and rain and wind. Pluto was once a living world, a place we'd have called homelike." Burl shivered a bit. "Out here? So far from the Sun? How and when?" Russ shrugged. "We'll find that out. But the evidence is unmistakable." They walked on. There was a low, cracked wall on the other side of the hill, and beyond the wall stood the roofless ruins of a stone house, silent and gray in the airless scene. They waited with surprise and uncertainty. Haines drew his compressed air pistol, but there was no movement. The scene remained dead and still--the windows of the house were dark. They advanced on it and flashed a light inside. It was an empty shell. There was no glass within the unusually wide and low window openings, and no door. "They went in and out the windows," commented Burl, ducking through one of the openings. "And they weren't built like us." "No," said Russ, "there's no reason to suppose the inhabitants would have been built like human beings." Inside there was nothing to see, and they left. Beyond, they found a straight depression in the ground filled with flat swirls of cosmic dust. "This looks like a road," said Haines. They returned to the rocket plane in order to follow the dead roadway more easily. Passing between the low, dark cliffs of rocky mountains, they came to a plain marked by thousands of columns of rock, pieces of crumbling walls, and many straight depressions that must have been streets. It was the remains of a world that had died.