Faint and distant, the sun fell swiftly behind the close horizon and three warm moons of Pluto climbed from the jagged rocks. Their pale, green light spread upon the rearing crags of dusty silica in a scintillating blanket of emerald, and gleamed richly upon the patches of white lichen. As Rusty Carter strode down the winding trail from his cave, he gave no thought to the prismatic scene. Even his analytical eyes, veteran of ten years with the Tele-news, were not concerned. He had seen it in day