"No, silly! The two Stanton boys and their mother. One of them is in that 'wheeled contraption'. It's called a therapeutic chair." "Oh? So the poor kid's been hurt. What's so interesting about that, aside from morbid curiosity?" The boy pushing the chair went around a bend in the walkway, out of sight, and Frobisher went back to his coffee while his wife spoke. "Their names are Mart and Bart. They're twins." "I should think," Frobisher said, applying himself to his breakfast, "that the mother would get a self-powered chair for the boy instead of making the other boy push it." "The poor boy can't control the chair, dear. Something wrong with his nervous system. I understand that he was exposed to some kind of radiation when he was only two years old. That's why the chair has all the instruments built into it. Even his heartbeat has to be controlled electronically." "Shame." Frobisher speared a bit of sausage. "Kind of rough on both of 'em, I'd guess." "How do you mean?" "Well, I mean, like.... Well, for instance, why are they going over to the play area? Play games, right? The one that's well has to push his brother over there--can't just get out and go; has to take the brother along. Kind of a burden, see? "And then, the kid in the chair has to sit there and watch his brother play basketball or jai alai, while he can't do anything himself. Like I say, kind of rough on both of them." "Yes, I suppose it must be. More coffee?" "Thanks, honey. And another slice of toast, hunh?" VIII The two objects floating in space both looked like pitted pieces of rock. The larger one, roughly pear-shaped and about a quarter of a mile in its greatest dimension, was actually that--a hunk of rock. The smaller--_much_ smaller--of the two was a camouflaged spaceboat. The smaller was on a near-collision course with reference to the larger, although their relative velocities were not great. At precisely the right time, the smaller drifted by the larger, only a few hundred yards away. The weakness of the gravitational fields generated between the two caused only a slight change of orbit on the part of both bodies. Then they began to separate. But, during the few seconds of their closest approach, a third body had detached itself from the camouflaged spaceboat and shot rapidly across the intervening distance to land on the surface of the floating mountain. The third body was a man in a spacesuit. As soon as he landed, he sat down, stock-still, and checked the instrument case he held in his hands. No response. Thus far, then, he had succeeded. He had had to pick his time precisely. The people who were already on this small planetoid could not use their detection equipment while the planetoid itself was within detection range of Beacon 971, only two hundred and eighty miles away. Not if they wanted to keep from being found. Radar pulses emanating from a presumably lifeless planetoid would be a dead giveaway.