* * * * * They paused in the big ore-loading lock to reclamp their pressure suit helmets, and looked down at the jagged chunk of rock a hundred yards below them. In the lock they had found scooters ... the little one-man propulsion units so commonly used for short distance work in space ... but decided not to use them. "They're clumsy," Johnny said, "and the bumper units in your suits will do just as well for this distance." He looked down at the rock. "I'll take the center section. You each take an edge and work in. Look for any signs of work on the surface ... chisel marks, Murexide charges, anything." "What about the dark side?" Greg asked. "If we want to see anything there, we'll either have to rig up lights or turn the rock around," Johnny said. "Let's cover this side first and see what we come up with." He turned and leaped from the airlock, moving gracefully down toward the surface, using the bumper unit to guide himself with short bursts of compressed CO_{2}, from the nozzle. Greg followed, pushing off harder and passing Johnny halfway down. Tom hesitated. It looked easy enough ... but he remembered the violent nausea of his first few hours of free fall. Finally he gritted his teeth and jumped off after Greg. Instantly he knew that he had jumped too hard. He shot away from the orbit-ship like a bullet; the jagged asteroid surface leaped up at him. Frantically he grabbed for the bumper nozzle and pulled the trigger, trying to break his fall. He felt the nozzle jerk in his hand, and then, abruptly, he was spinning off at a wild tangent from the asteroid, head over heels. For a moment it seemed that asteroid, orbit-ship and stars were all wheeling crazily around him. Then he realized what had happened. He fired the bumper again, and went spinning twice as fast. The third time he timed the blast, aiming the nozzle carefully, and the spinning almost stopped. He fought down nausea, trying to get his bearings. He was three hundred yards out from the asteroid, almost twice as far from the orbit-ship. He stared down at the rock as he moved slowly away from it. Before, from the orbit-ship, he had been able to see only the bright side of the huge rock; now he could see the sharp line of darkness across one side. But there was something else.... He fired the bumper again to steady himself, peering into the blackness beyond the light-line on the rock. He snapped on his helmet lamp, aimed the spotlight beam down to the dark rock surface. Greg and Johnny were landing now on the bright side, with Greg almost out of sight over the "horizon" ... but Tom's attention was focussed on something he could see only now as he moved away from the asteroid surface.