Slowly, like a car backing out of a garage, it pulled out of the hole in the satellite. Nowhere on its surface was there a mark or a scratch. When it was finally free of the satellite, it turned a little, its nose pointing off into space. A pale, rose-colored glow appeared at the tail of the ship, and the cigar of blue metal leaped forward. To all intents and purposes, it simply vanished. "That," said the major in awe, "is what I call acceleration." * * * * * "Here's the way I see it, Mr. President," said MacIlheny several hours later. "When he cracked up by accidentally plowing into Number Four, something happened to his energy supply. Maybe he was already low, I don't know. Anyway, he was out of fuel." "What do you think he used for fuel?" "The most efficient there is," said MacIlheny. "Pure energy. Imagine some sort of force field that will let energy in, but won't let it out. It would be dead black on the outside, just like that whatever-it-was in the alien's ship. He just set off the H-bomb inside that field; what little radiation did get out made the field look gray--and that's a damned small loss in comparison with the total energy of that bomb." "You know, Fitz, I'm going to have a hell of a job explaining where that bomb went," said the President. "Yeah, but we've got his gun or whatever in exchange." "But how do you know our technicians will be able to figure it out?" "I think they will," MacIlheny said. "Their technology must be similar to ours or he wouldn't have been able to figure out how to fire the jets on the satellite or how to set off that bomb. He wouldn't have even known what the bomb was unless he was familiar with something similar. And he wouldn't have been able to blank out our controls unless he had a good idea of how they operated. They may be a little ahead of us, but not too much, and I'll bet we have some things they haven't." "The trouble is," the President said worriedly, "that we don't know where he came from. He knows where we are, but we don't have any idea where his home planet is." "That's true. On the other hand, we know something about his physical characteristics, while he doesn't know anything about ours. For instance, I doubt if he'd be happy here on Earth; judging by the helmet he wore, he can't stand too much light. He had it polarized almost black. Probably comes from a planet with a dim, red sun." "Well, Fitz, when they do come, I hope it's for trade and not for war." MacIlheny grinned. "It won't be war. Don't you remember? We've started trading already!"