"Sammy," said McCauley, "hold everything. I'll be over."

When people encounter each other only occasionally, there is no particular need for them to think intensively about each other's feelings. But three people isolated in an enforced intimacy much closer than that of cellmates have to take thought. When one of them is responsible for the other two, tact has to be practiced painstakingly. When one of the three is a young man who doesn't believe that anything can happen to him because nothing ever has, the situation calls for extreme care. McCauley had to use his brains if Randy and Sammy Breen were to be able to work with him under exacting conditions like these.

He unhooked his space rope, rehooked it past a junction, and pulled himself toward the place where Sammy Breen had come to a stop. It was, of course, at a place where two of the frame pieces of the Platform should join a third. They were to be bolted together and then another long section of framework would be added, which in turn would have yet another beam placed and bolted to it so the construction could continue. At the moment, however, a bolt hole needed to be reamed so the parts could be bolted together.

McCauley arrived at the corner of a triangle. When linked to all the others, this triangle would ultimately support the skin and hold the interior partitions of the Platform. Again he slipped his space rope over the junction, hooked it, followed it, and went on toward the place where Sammy Breen was. Sammy's voice came out of his helmet phones.

"I saw a man do this once in a circus," said Sammy. "I thought he was wonderful. But I can do it!"

McCauley looked up. Sammy Breen had his space rope hooked around the girder, to be sure. But now he floated, head toward Earth, with one finger barely touching the metal beam. A photograph would have shown him apparently supporting his whole weight on a single finger. But here there was no weight. Nothing drew Sammy toward either Earth or the Platform. But for his space rope, the lightest thrust of his finger would have sent him floating slowly, implacably, helplessly away from the spidery floating object, to drift alone through space forever.

"I hope you checked your rope before you came outside," McCauley said dryly.

"I did," said Sammy nonchalantly. "It's okay."

He tried to pull himself back to the girder with his fingers. He couldn't quite reach it. He was no more than half an inch from a fingertip hold that would have been more than enough, but he couldn't make it. He reached and reached, and his movements made his body in its space suit revolve ridiculously upside down and otherwise. Then he couldn't get his hand anywhere near the girder.

McCauley watched. He was unreasonably tense. But Sammy rather sheepishly gave a tug on his space rope and floated back to firm contact with the Platform.