The first was a scout ship of American Spaceways! Nat recognized the name: _Ceres_, remembered a telecast account of its disappearance in space. There was a neat little reward for information as to its whereabouts. Nat's lips curled in derision: it wouldn't equal the expense of his journey out here. There was a deep groove in the smooth material of the floor where the ship had been dragged through the doorway into the room. What machines could have done this work without leaving their own traces? He went to the other ships: all were small, mostly single or two-passenger craft. The last entry in the logs of many was to the effect that they were about to land on the Asteroid Moira to rescue a girl held captive there. None had crashed; all ships were in perfect order. But all were deserted. Two doors were gone from the interior of one of the vessels. They might have been removed for any of a hundred reasons--but why here? Nat's glance swept the room, came to rest on the figure of a heavy duty robot of familiar design. Semi-human in form, it looked like some misshapen, bent, headless giant. He inspected it: _Meyers Robot, Inc._ Earth designed for mining operations on Mars. "Well, Digger, I can see now how these ships were brought in here; that robot could move any one of these with ease. But that doesn't explain where the humans have gone. It might be space pirates using this asteroid for a base, or it might be some alien form of life. We're still free. Shall we beat it or stay and try to check this out?" He did not know how much of this got over to the spacehound, but the impressions he received in answer were those of approving their remaining where they were. "I suppose the best system is to explore the rest of the caves in order; let's go." Followed by Digger, he walked quietly toward the next cave on the left, slipped through the doorway, and, standing with his back against the wall, swung the light of his torch in a wide, swift arc about the room. Halfway around, he stopped abruptly; a slim, petite figure appeared clearly in the searchlight's glare. The girl he had seen on the televisor stood in the middle of the room, facing a telecaster, her back toward him. She did not seem aware of him as he moved forward. What could be wrong; surely that light would arouse her. The figure did not turn as he approached. So near was he now that he could seize her easily, still she made no move. Nat stepped to one side, flashed his torch in her face. Her beautifully-lashed eyes stared straight ahead unblinkingly; the expression on her lovely composed face did not change. A robot! He laughed bitterly. But then, he was not the only one....