Maitland removed his three-day beard with an effective depilatory cream he discovered in the bathroom, and settled down to wait. When Swarts arrived, the engineer said quietly, "Sit down, please. I have to talk with you." Swarts gave him the look of a man with a piece of equipment that just won't function right, and remained standing. "What is it now?" "Look," Maitland said, "Ingrid has told me that men never reached the planets. _You_ ought to know how I feel about space flight. It's my whole life. Knowing that my work on rockets is going to pay off only in the delivery of bombs, I don't want to go back to the 20th Century. I want to stay here." Swarts said slowly, "That's impossible." "Now, look, if you want me to cooperate...." The big man made an impatient gesture. "Not impossible because of me. Physically impossible. Impossible because of the way time travel works." Maitland stared at him suspiciously. "To displace a mass from its proper time takes energy," Swarts explained, "and it's one of the oldest general physical principles that higher energy states are unstable with respect to lower ones. Are you familiar with elementary quantum theory? As an analogy, you might regard yourself, displaced from your proper time, as an atom in an excited state. The system is bound to drop back to ground state. In the atomic case, the time which elapses before that transition occurs is a matter of probabilities. In the case of time travel, it just depends on the amount of mass and the number of years the mass is displaced. "In short, the laws of nature will insist on your returning to 1950 in just a few days." Maitland looked at the floor for a while, and his shoulders sagged. "Your memories of this will be faded," Swarts said. "You'll forget about what Ingrid has told you--forget you were ever here, and take up your life where you left off. You were happy working on rockets, weren't you?" "But--" Maitland shook his head despairingly. Then he had an idea. "Will you let me do one thing, before I go back? I realize now that our time is limited, and you have a lot of tests to give me, but I'm willing to help speed things up. I want to see the stars, just once, from deep space. I know you'll make me forget it ever happened, but once in my life.... You have vessels--_vliegvlotter_, Ingrid called them--that can go into space. If you'd give me just a couple days to go out there, maybe circle the Moon...?" There was a pleading note in his voice, but he didn't care. Swarts regarded him dispassionately for a moment, then nodded. "Sure," he said. "Now let's get to work." * * * * *