_Ethan squinted at it. "I could make you think it was. Get it enlarged, solidified. Have them make it soft, big as a baby. You could hold it in your lap."_ _"Outgrew playthings years ago." Amantha adjusted the chair switch, but the rocking motion was no comfort._ _Ethan turned the picture over, face down. "Nope. Hate to back you up, 'Mantha, but it ain't the same. There's nothing like a baby, wettin' and squallin' and smilin', stubborn when it oughtn't to be and sweet and gentle when you don't expect it. Robo-dolls don't fool anybody who's ever held the real thing."_ In the interval, Earth had drawn ahead. The gap between the two planets was widening. "That's another fallacy," objected the training director. "The body can stand just so much acceleration. We're near the limit. What good are faster ships?" "That's your problem," said Demarest. "Get me tougher crewmen. Young, afraid of nothing, able to take it." It always ended here--younger, tougher, the finest the race produced--and still not good enough. And after years of training, they had twenty-five months to function as spacemen. It was a precious thing, flight time, and each trip was as short as science could make it. Conjunction was the magic moment for those who went between the planets. It was the heredity block that kept Man squeezed, confined to Earth, Mars and Venus, preventing him from ranging farther. The heredity block was a racial quantity, the germ plasm, but not just that. Crew and passengers were protected as much as possible from radiation encountered in space and that which originated in the ship's drive. The protection wasn't good enough. Prolonged exposure had the usual effects, sterilization or the production of deformed mutations. Man was the product of evolution on a planet. He didn't step out into space without payment. * * * * * The radiation that damaged genes and chromosomes and tinier divisions also struck nerve cells. Any atom might be hit, blazing, into fission and decaying into other elements. The process was complicated. The results were not: the nerve was directly stimulated, producing aural and visual hallucinations. Normally, the hallucination was blanked out. But as the level of body radioactivity increased, so did the strength of the vision. It dominated consciousness. The outside world ceased to have meaning. The hallucination took only one form, a beautiful woman outside the ship, unclad and beckoning. It was the image of vanished fertility that appeared once the person was incapable of reproducing _as a human_. Why this was so hadn't been determined. Psychologists had investigated and learned only that it invariably occurred after too great exposure. There was another thing they learned. No, that had come first. This was the reason they had investigated.