For a time Kim sat still and sweat poured out on his skin. Because their chances had seemed slight indeed. To stop a space-ship at transmitter-speed was impossible with manual means, anyhow. It could cross a galaxy in the tenth of a millisecond. So Kim had devised a radiation-operated relay which threw off the drive when the total radiation reaching a sensitive plate in the bow had reached an adjustable total. If in an ordinary flight the _Starshine_ headed into a sun--unlikely as such an occurrence was--the increased light striking the relay-plate would throw off the drive before harm came. But this time they had needed to approach fatally close to a star. So Kim had reversed the operation of the relay. It would throw off the drive when the amount of light reaching it dropped below a certain minimum. That could happen only if the ship came up behind the planet, so the sun was blacked out by the world's shadowed night-side. It had happened. The glare was cut off. The transmitter-drive followed. The _Starshine_ floated within a bare few million miles--perhaps less than one million--of a blue-white dwarf star, and the two humans in the ship were alive because they had between them and the sun's atomic furnaces, a planet some six thousand miles in diameter. "We don't know how our velocity matches this thing," said Kim after an instant. "We could be drifting toward the edge of the shadow. You watch the stars all around. Make sure I head directly for that blackness. When we touch, I'll see what I can find out." He reversed the ship's direction. He let the _Starshine_ float down backward. The mass of unsubstantial darkness seemed to swell. It engulfed more and more of the cosmos.... A long, long time later, there was a strange sensation in the feel of things. Dona gave a little cry. "Kim! I feel queer! So queer!" Kim moved heavily. His body resisted any attempt at motion, and yet he felt a horrible tension within him, as if every molecule were attempting to fly apart from every other molecule. The controls of the ship moved sluggishly. Each part of each device seemed to have a vast inertia. But the controls did yield. The drive did come on. A little later the sensation ended. But both Kim and Dona felt utterly exhausted. "It--was getting dark, too," said Dona. She trembled. "When we tried to move," said Kim, "our arms had a tendency to move at right angles to the way we wanted them to--at all the possible right angles at once. That was the edge of the shield, Dona. Now we'll see what we've got." He uncovered the recording cabinet. There had been no need to set up instruments especially for the analysis of the field. They had been a part of the _Starshine's_ original design for exploration. Now Kim read the records.