"All right," said Catherine. "Now tell us how to repair the situation." Her tone was light--after all, the answer was obvious--but it didn't escape Gilchrist that she _had_ asked him to speak. Or was he thinking wishfully? "We turn off the pile, empty the pipes, and go into the room in spacesuits," he said. "Probably the simplest thing would be to drill an outlet for the nitrogen vein and drop a thermite bomb down there ... that should flush it out in a hurry. Or maybe we can lay an impermeable floor. In any event, it shouldn't take more than a few days, which the batteries will see us through. Then we can go back to operation as usual." Vesey nodded. "I'll put Jahangir on it right away." He stood up and extended his hand. "As for you, Dr. Gilchrist, you've saved all our lives and--" "Shucks." His cheeks felt hot. "It was my own neck too." Before his self-confidence could evaporate, he turned to Catherine. "Since we can't get back to work for a few days, how about going down to the bar for a drink? I believe it'll soon be functioning again. And, uh, there'll doubtless be a dance to celebrate later--" "I didn't know you could dance," she said. "I can't," he blurted. They went out together. It is not merely inorganic reactions which require a catalyst.