For an instant the outcome remained uncertain, a see-saw contest of strength. Then Corriston had the knife and the struggle was over. Corriston made a mistake then of relaxing a little. Instantly, the killer rolled sideways, broke Corriston's grip, and was on his feet. He did not attempt to retaliate in any way. He simply disappeared into the darkness, breathing so loudly that Corriston could tell when the distance between them had dwindled to the vanishing point. Corriston sat very still in the darkness, holding on tightly to the knife. His triumph had been unexpected and complete. It had been close to miraculous. Strange that he should be aware of that and yet feel only a dark horror growing in his mind. Strange that he should remember so quickly again the horror of a man gasping out his life with a thorned barb protruding from his side. It had begun a half-hour earlier in the general passenger cabin. It had begun with a wonder and a rejoicing. Tremendous and glittering, the Space Station had come floating up out of the Big Dark like a golden bubble on an onrushing tidal wave. It had hovered for an instant in the precise center of the viewscreen, its steep, climbing trail shedding radiance in all directions. Then it had descended vertically until it almost filled the lower half of the screen, and finally was lost to view in a wilderness of space. When it appeared for the second time, it was larger still and its shadow was a swiftly widening crescent blotting out the nearer stars. "There it is!" someone whispered. It had been unreasonably quiet in the general passenger cabin, and for a moment no other sound was audible. Then the whisper was caught up and amplified by a dozen awestruck voices. It became a murmur of amazement and of wonder, and as it increased in volume, the screen seemed to glow with an almost unbelievable brightness. Everyone was aware of the brightness. But how much of it was subjective no one knew or cared. To a man in the larger darkness of space, a dead sea bottom on Mars, or a moon-landing ship wrapped in eternal darkness on a lonely peak in the Lunar Apennines may glow with a noonday splendor. "They said a space station that size could never be built," David Corriston said, leaning abruptly forward in his chair. "They quoted reams of statistics: height above the center of the Earth in kilometers,