Farrel cleared his throat. "You know how important it is that this colony be established? You know that, don't you? In twenty years or so the ships will start arriving. Hundreds of them. Because we sent a message back to Earth saying we'd found a habitable planet. Thousands of people from Earth, coming here to the new world we're supposed to get busy and carve out for them. We were selected for that task--first of judging the right planet, then of working it over. Engineers, chemists, agronomists, all of us--we're the task force. We've got to do the job. We've got to test, plant, breed, re-balance, create. There'll be a lot of trial and error. We've got to work out a way of life, so the thousands who will follow can be introduced safely and painlessly into the--well, into the organism. And we'll need new blood for the jobs ahead. We'll need young people--" Mary said, "A few years one way or the other won't matter much, Doc. Five or six years from now this place will be a lot safer. Then we women will start producing. But not now." "It won't work that way," Farrel said. "We're none of us kids any longer. I'm fifty-five. Ralph, you're forty-three. I realize that I must be getting old to think of you as young. Mary, you're thirty-seven. We took a long time getting here. Fourteen years. We left an Earth that's dying of radioactive poisoning, and we all got a mild dose of that. The radiation we absorbed in space, little as it was, didn't help any. And that sun up there--" again he nodded at the port--"isn't any help either. Periodically it throws off some pretty damned funny stuff. "Frankly, we're worried. We don't know whether or not we _can_ have children. Or _normal_ children. We've got to find out. If our genes have been bollixed up, we've got to find out why and how and get to work on it immediately. It may be unpleasant. It may be heart-breaking. But those who will come here in twenty years will have absorbed much more of Earth's radioactivity than we did, and an equal amount of the space stuff, and this sun will be waiting for them.... We'll have to know what we can do for them." "I'm not a walking laboratory, Doc," Mary said. "I'm afraid you are, Mary. All of you are." Mary set her lips and stared out the port. "It's got to be done, Mary." She didn't answer. "It's going to be done." "Choose someone else," she said. "That's what they all say." She said, "I guess this is one thing you doctors and psychologists didn't figure on, Doc." "Not at first," Farrel said. "But we've given it some thought." MacGuire had installed the button convenient to Farrel's right hand, just below the level of the desk-top. Farrel pressed it. Ralph and Mary Pornsen slumped in their chairs. The door opened, and Doctor John J. MacGuire and Ted Harris, the Exodus VII's chief psychologist, came in. * * * * *