One of the Schweitzer twins gave a laugh. "There's one way to find out," he said, and yanked the outlet cup off his nose. He inhaled deeply, smiling. "Look, Ma, I'm breathing," he laughed. He took deep, gulping breaths. He did a somersault. He pounded his chest. "It's all a matter of lungs," he said. "If you don't have lungs, well, you just can't manage it, that's all...." He chattered on--and then, abruptly, his eyes took on a startled look. He began to breathe more rapidly. His breathing became labored. He fumbled for the outlet cup. He raised it to his nose--it slipped out of his now frantic hands-- Harvey and Dr. Lurie grabbed him as he wavered, and fitted the outlet cup back over his nose. The youth stood there with trembling knees. "Sit down, kid," Harvey said. "Relax--you'll be all right." The settlers stood in a stricken silence. They had been fully informed of the situation, they knew precisely what would happen, yet seeing it demonstrated this way was an appalling thing. They could see now, graphically, the precarious condition of their existence. There was no more shouting. There was little they had to say to each other now. Carsing came out of the building. He was instantly recognizable, despite the cup over his nose. With his nervous, jerky steps, he walked to a low platform and held up his hand. With him were two men, both gray-haired and darkly tanned. "These are your guides," Carsing announced. "Go get your carts and move out." "Hey!" shouted Red Brace. "What pulls these carts?" "You do," Carsing said coldly. "You mean there aren't any horses--or trucks?" Carsing's mouth twisted. "No--no horses or trucks. Or tractors or washing machines. You'd better make up your minds to that right now. Transporting any large mechanical equipment all the way out here would be impossibly expensive. Outside of the few small devices we absolutely had to have, we've imported nothing. So please don't come complaining to me. From now on, you'll have to learn to improvise with native materials. All right"--he gestured to the two men who stood drooping behind him, as if leaning on invisible poles--"get them out and get going." Carsing left the platform and went back into the building. For a moment, there was no motion among the settlers. Then several started maneuvering the heavily loaded carts, the men embarrassedly accepting the assistance of their wives. The two guides waited, still leaning on their phantom supports, talking softly, hardly looking at the settlers. When all the carts were lined up in a straggling column, the two guides ambled to the road that led away from the spaceport. They paused and looked back briefly with worn eyes. Then with a motion that was more a shrug than a gesture, they started up the brown dirt road.