After graduation Gregory Manning had gone on to world fame, had roamed over the face of every planet except Jupiter and Saturn, had visited every inhabited moon, had climbed Lunar mountains, penetrated Venusian swamps, crossed Martian deserts, driven by a need to see and experience that would not let him rest. Russell Page had sunk into obscurity, had buried himself in scientific research, coming more and more to aim his effort at the discovery of a new source of power ... power that would be cheap, that would destroy the threat of Interplanetary dictatorship. Page turned away from the rectifier room. "Maybe I'll have something to show Greg soon," he told himself. "Maybe, after all these years...." * * * * * Forty minutes after Page put through the call to Chicago, Gregory Manning arrived. The scientist, watching for him from the tiny lawn that surrounded the combined home and laboratory, saw his plane bullet into sight, scream down toward the little field and make a perfect landing. Hurrying toward the plane as Gregory stepped out of it, Russell noted that his friend looked the same as ever, though it had been a year or more since he had seen him. The thing that was discomfiting about Greg was his apparently enduring youthfulness. He was clad in jodhpurs and boots and an old tweed coat, with a brilliant blue stock at his throat. He waved a hand in greeting and hurried forward. Russ heard the grating of his boots across the gravel of the walk. Greg's face was bleak; it always was. A clean, smooth face, hard, with something stern about the eyes. His grip almost crushed Russ's hand, but his tone was crisp. "You sounded excited, Russ." "I have a right to be," said the scientist. "I think I have found something at last." "Atomic power?" asked Manning. There was no flutter of excitement in his voice, just a little hardening of the lines about his eyes, a little tensing of the muscles in his cheeks. Russ shook his head. "Not atomic energy. If it's anything, it's material energy, the secret of the energy of matter." They halted before two lawn chairs. "Let's sit down here," invited Russ. "I can tell it to you out here, show it to you afterward. It isn't often I can be outdoors." "It is a fine place," said Greg. "I can smell the pines." The laboratory perched on a ledge of rugged rock, nearly 7,000 feet above sea level. Before them the land swept down in jagged ruggedness to a valley far below, where a stream flashed in the noonday sun. Beyond climbed pine-clad slopes and far in the distance gleamed shimmering spires of snow-capped peaks. From his leather jacket Russ hauled forth his pipe and tobacco, lighted up. "It was this way," he said. Leaning back comfortably he outlined the first experiment. Manning listened intently.