EVEN ON THE earth shadows are frequently good places to hide. They may show up, of course, against lighted surroundings, but if there is not too much light from the side, one can step into a shadow and become remarkably hard to see.

Beyond the earth, where there is no air to scatter light, they should be even better. The earth's own shadow, for example, is a million-mile-long cone of darkness pointing away from the sun, invisible itself in the surrounding dark and bearing the seeds of still more perfect invisibility- for the only illumination that enters that cone is starlight and the feeble rays bent into its blackness by the earth's thin envelope of air.

The Hunter knew he was in a planet's shadow though he had never heard of the earth; he had known it ever since he had dropped below the speed of light and seen the scarlet-rimmed disk of black squarely ahead of him; and so he took it for granted that the fugitive vessel would be detectable only by instruments. When he suddenly realized that the other ship was visible to the naked eye, the faint alarm that had been nibbling at the outskirts of his mind promptly rocketed into the foreground.

He had been unable to understand why the fugitive should go below the speed of light at all, unless in the vague hope that the pursuer would overrun him sufficiently to be out of detection range; and when that failed, the Hunter had expected a renewed burst of speed. Instead, the deceleration continued. The fleeing ship had kept between his own and the looming world ahead, making it dangerous to overhaul too rapidly; and the Hunter was coming to the conclusion that a break back on the direction they had come was to be expected when a spark of red light visible to the naked eye showed that the other had actually entered an atmosphere. The planet was smaller and closer than the Hunter had believed.