"Well, Arne, I haven't finished checking up on our little conjecture; the calculator over there is still working on it. But while I was waiting I looked through our friend Pappas's locker. You may already have noticed what I found." He waved the gun. "Where did you find our friend, by the way?" Birkerod smiled. "First place I looked." "The lifeboat?" "Yeah." "What was he doing?" "Nothing. I think I know how our little conjecture's going to turn out, though." He turned to Pappas, who had followed the exchange tensely. "You know, Nick, my father was a fellow-countryman of yours back on Earth." "Countryman?" "That's right. He lived just north of Winnipeg. My mother was a Canadian, too. Both of them were in the second batch of colonists that left for Callisto. But it doesn't mean much to call you a Canadian any more, does it? Garcia and you and I, we're all Callistans now." "Sure," said Pappas, wondering. * * * * * Callisto: A cold world. A small new world, and a cold world, and incredibly distant from the planet that had evolved its settlers. In the thirty years since the exploration of Jupiter's satellites had begun, Callisto had had a very different history from the rest. On Ganymede, a hundred or so engineers had been working all that time on the tremendous task of raising the satellite's mean temperature to the point where an atmosphere could be provided and open-air cities and farms built in which Earthmen could live. The smaller satellites had been largely ignored. But it had been found that Callisto had large deposits of ore of such quality that, in spite of the tremendously long haul required to carry anything from there to the inner planets, it was worth while beginning mining operations. Up went the insulated, airtight domes, out came the colonists, down went the mine shafts. It was a hard life. Crystalline rock was cut by machines at the mine-faces, and by the time other machines had brought it up the shafts to the surface-level in the domes, it had become amorphous and powdery, its crystalline structure destroyed by being heated to twenty degrees below zero Centigrade. When you repaired machinery below the surface, you wore sixty kilograms of spacesuit (Earth weight), and a failure of any item of equipment or a fumble by any member of your crew might mean sudden death. The walls of the dome shut you in from the sky, for the vacuum out there was death too; when you did get up to the observatory to see the sky, you saw Jupiter, weirdly streaked with brilliant color--if your dome was on the side of Callisto toward Jupiter. Otherwise, you looked across twenty million kilometers of vacuum to the nearest star.