Janu the Martian, away on the other side of the pit, made a shrill wailing cry. Loris and Pendleton flinched away like dogs afraid of the whip, looking upward. MacVickers glimpsed a dark tentacled shape on the catwalk above, just before the shattering electricity coursed through him. He screamed, once. And then Birek moved. He struck Loris and Pendleton and the blue-sheathed Earthman out of the way like children. His left leg took MacVickers behind the knees in the same instant that his right hand pushed MacVickers' face. MacVickers fell heavily on his back, screaming at the contact of the metal floor. Then Birek sprawled over him, shielding his body with the bulk of his own. The awful shocking pain was lessened. Lying there, looking up into Birek's pale eyes, MacVickers made his twitching lips say, "Why?" Birek smiled. "The current doesn't hurt much any more. And I want you for myself--to break." MacVickers drew a deep, shuddering breath and smiled back, the lines deep in his lean cheeks. * * * * * He had no clear memories of that shift. Heat and motion and strangling air, and Janu coughing with a terrible, steady rhythm, his own hands trying to guide the oil can. Toward the end of the time he fainted, and it was Birek who carried him up the ladder. He had no way of knowing how long after that he came to. There was no time in that little hell. The first thing he noticed, with the hair-trigger senses of a man trained to ships, that the motion of the room was different. He sat up straight on the bunk where Birek had laid him. "The tidal wave," he said, over a quick stab of fear. "What...." "We ride it out," said Loris bitterly. "We always have." MacVickers knew the Jovian Moons pretty well. Remembering the tremendous tides and winds caused by the gravitational pull of Jupiter, he shuddered. There was no solid earth on Io, nothing but mud. And the extraction plant, from the feel of it, was a hollow bell sunk under it, perfectly free. It had to be free. No mooring cable made could stand the pull of a Jupiter-tide. "One thing about it," said Pendleton with quiet viciousness. "It makes the bloody Jovies seasick." Janu the Martian made a cracked, harsh laugh. "So they keep a weak current on us all the time." His hatchet-face was drawn, his yellow cat-eyes lambent in the dim light. The men sprawled on their bunks, not talking much. Birek sat on the end of his, watching MacVickers with his pale still eyes. There was a tightness in the room. It was coming. They were going to break him now, before he hurt them. Break him, or kill him. MacVickers wiped the sweat from his face and said, "I'm thirsty." Pendleton pointed to a thing like a horse-trough against the bulkhead. His eyes were tired and very sad. Loris was scowling at his stained and faintly filmed feet.