"I wish I hadn't done it," Morton confided. "It's one of those things that shouldn't happen. It's bad enough to have a giant squid to account for. They tell me it's a new species, by the way. Never found or even described before. One of the _Pelorus_ men tells me it's an immature specimen, too. It's not full-grown! What will a grown-up one be like?" "I have a hunch we'll find out when those submerged giants reach the surface," said Davis unhappily. Terry said, "The one we killed couldn't get out of the water. I wonder if the adult forms can walk over the land!" Davis stared. "Should we send Deirdre to safety on the _Esperance_?" "Safety?" asked Terry. "On a boat? When a mass of bubbles from undersea could provoke such a turmoil in the water that no ship could stay afloat? That's how one ship disappeared. It might be the _Esperance's_ turn next. Who knows?" Then he added, "There's no limit to the size of a swimming creature!" A bald-headed member of the tracking station staff walked in. He carried an object of clear plastic. It was a foot and a half long, about six inches in diameter. There was an infinite complexity of metallic parts enclosed in the plastic. "I caught one of the fishermen making off with this," he said in a flat voice. "It was fastened to one of the squid's shorter arms. The fishermen didn't want to give it up. The skipper claimed it as treasure-trove." He put it down on the table. Davis, Terry and Morton looked at it. Then Morton shrugged his shoulders, almost up to his ears. "The intelligent being that made it," said Davis, "apparently came down from the sky in a bolide. That's easier to believe than that a submarine civilization of earthly origin lives down in the depths. But why would anybody prefer the bottom of the sea to--anywhere else on earth? Where would such a creature come from?" Deirdre walked in and stood by the table, watching Terry's face. The bald-headed man said, "I could believe some pretty strange things, but you can't make me believe that a creature can develop intelligence without plenty of oxygen. There's not much free oxygen at the bottom of the sea." "But there's something intelligent down there," said Davis doggedly. "If it has to have free oxygen, you've only raised the question of where it gets it. Maybe it brings it." Deirdre shook her head. "Foam," she said. The four men stared at her. Then Terry said sharply, "That's it! On the _Esperance_ there's a picture of a huge mass of foam on the sea. A ship dropped right out of sight right into it. Deirdre found the answer! Something down below needs free oxygen. In quantity. Why not get it from the water? What to do with the hydrogen that is left? Let it loose! It'll come to the surface, make a foam-patch...."