The life watch

By Lester del Rey
Norden could not trust his own darkly terrifying thoughts and impulses. Yet he kept a life watch over the whole human race.
The spread of an alien culture across wide wastes of space, with its almost inevitable, remorseless destruction of human life, has chilling implications even for the literal-minded. When mirrored in the bright, adventurous prism of modern science fiction it offers unparalleled opportunities to a writer of Lester del Rey's stature. We're sure you'll agree that he's scored a triumph in this brilliantly imaginative yarn.
Norden could feel dread knot his mind as he watched the tiny blue speck against the black sky. It was a senseless, unnatural emotion, and he knew it. The searing blue point of flame could only mean that the approaching ship was powered by atomic rockets—and the Aliens drove their ships in some mysterious manner, without any kind of reaction motor. The object coming down toward the tiny asteroid could only be of terrestrial origin, powered by a human device.
Yet his fear grew worse. He shook his head, wondering again how close to insanity he had drifted. His eyes darted sideways, scanning the wreckage that had been his laboratory, then back to the descending ship. Mercifully, he couldn't remember most of what had happened. He only knew that it had been sufficiently bad to drive any human close to the brink of madness. It would have been torturing enough to be left alone for days in a wrecked and airless dome while the oxygen tanks were used up, one by one. But to have seen Hardwick's face when the Aliens caught him....
He tried to stop thinking about it. The Aliens were only vague shadows in his mind now—the picture of what must have happened as remote and unreal as his memories of struggling free from the wreckage.
Somehow, he'd survived against incredible odds, undetected by the Aliens. He'd dug out the emergency transmitter and tried signaling for help. Now apparently, before the last tank of oxygen on his back had been used up completely, rescue had come. He should have been ecstatic with relief.