The heads of the men in the room jerked up at the cry, and they looked around and at each other, with puzzled expressions. Old Beard clapped a firm hand over Dark's mouth and hissed in his ear: "Fool! Let's get out of here!" As quietly as possible, they made their way back. Through the ventilator behind them came the murmur of querulous voices. When they had climbed back down the stairs and, with Happy and Shadow, made their way back through the fissure, Old Beard fixed penetrating eyes on Dark and said: "I told you to keep quiet up there! What was that exclamation all about?" "It's something very strange," murmured Dark, his face thoughtful and bemused. "But you evidently recognized that man, too. Who is he?" "Yes, I know him very well," answered Old Beard, with deep bitterness in his tone. "That's Goat Hennessey. But that's the first time I've seen him in twenty-five years. He must have just come here recently." "Goat Hennessey? I heard of him when I was in Mars City." "Goat Hennessey was one of my most trusted friends," said Old Beard. "If you bear my earlier memories, I'm surprised you didn't recognize him as Goat Hennessey, too." "I recognized him as someone else," said Dark in a low voice. "We worked together," went on Old Beard. "I was a leader in the effort to solve our problem through extrasensory perception, and he was the major scientist in the group attempting to solve it by genetic change. We worked together and we went into the desert together with the others when the government banned our experiments. "But Goat was the man who sold out. He betrayed us to the government--for what price I don't know. And when government agents raided us and broke up our organization and captured me, Goat Hennessey kidnapped my young and pregnant wife, and I never saw her again. "I'm glad Goat Hennessey is here, because now I can get to him. And when I can reach him, I'm going to kill him. I'd like to kill him as slowly and painfully as he killed the heart inside of me!" As Old Beard spoke these last words, his face was tense, his fists clenched and a somber fire burned in his pale eyes. Then, slowly, the fire died out and he turned his eyes, once more cool and rational, a little quizzical, on Dark. "Didn't you call him 'father'?" he asked. "Yes," said Dark in a low voice. "But I'd rather not talk about it right now." He looked at Old Beard, and seemed to be ridding himself, with an effort, of a deep introversion. "There's one thing that I've remembered as a result of seeing Goat Hennessey," said Dark in a firmer voice. "This place isn't too far from a place in the Xanthe Desert where Goat conducted some significant experiments. If he left any of his records there--and I'm thinking of some in particular--they might go a long way toward solving the problem we've all be working on for so long. So now I know what to do next: I'm going to Ultra Vires." Old Beard smiled sadly.