"Listen Jason," he said. "The walls you've built around the settlement weren't meant to keep you from going outside. You're not a self-sufficient little community ... you're cut off from mankind's memory, from his dreams, from his ambitions. You can't even start to rebuild a civilization--and if you do try, don't you think the people outside will learn about it? Don't you think they've got a right to share in whatever progress the settlement makes? And if you don't let them, don't you realize that they'll destroy the settlement?" Silence. * * * * * "I'm a historian," Tom continued, "and I know that a civilization can't exist in a vacuum. If outsiders don't conquer it, it'll rot from within. It's happened to Babylonia, Greece, Rome, China, even. Over and again. The Soviets built an Iron Curtain around themselves, and wiped themselves out because of it. "Don't you see, Jason? There are only two types of animals on this planet: the gamblers and the extinct. It won't be easy to live with the outsiders, there'll be problems of every type. But the alternative is decay and destruction. _You've got to take the chance, if you don't you're dead._" A long silence. Finally Jason said, "You've only got about a half-hour's worth of oxygen left. Will you tow the satellite into the proper position?" Tom stared at the planet unseeingly. "Yes," he mumbled. "I'll have to check some calculations with the astronomers," Jason's voice buzzed flatly in his earphones. A background murmur, scarcely audible over the crackling static. Then Ruth's voice broke through, "Tom, Tom, you can't do this! You won't be able to get back!" "I know," he said, as he started pulling his way along the lifeline back to the ship. "_No!_ Come back, Tom, please. Come back. Forget the satellite. Come back and explore the cities. I'll go with you. Please. Don't die, Tom, please don't die...." "Ruth, Ruth, you're too young to cry over me. I'll be all right, don't worry." "No, it isn't fair." "It never is," Tom said. "Listen, Ruth. I've been dead a long time. Since the bombs fell, I guess. My world died then and I died with it. When I came to the settlement, when I agreed to make this flight, I think we all knew I'd never return, even if we wouldn't admit it to ourselves. But I'm just one man, Ruth, one small part of the story. The story goes on, with or without me. There's tomorrow ... your tomorrow. I've got no place in it, but it belongs to you. So don't waste your time crying over a man who died eighteen years ago." He snapped off his suit radio and went the rest of the way to the ship in silence. After locking the hatch and pumping air back into the cabin, he took off his helmet. _Good clean canned air_, Tom said to himself. _Too bad it won't last longer._ * * * * * He sat down and flicked a switch on the radio console. "All right, do you have those calculations ready?"