There were dull concussions everywhere. Giant squids writhed in death-agonies. White foam-patches appeared here and there--but somehow haphazardly--as if fumbling for the ships. One patch swept close to _La Rubia_, and that small derelict seemed to tremble. And then the fishing boat touched the very edge of the white stuff, and was engulfed in it. She vanished instantly, as if she had fallen into a hole in the sea. When the foam-patch passed on, the sea was empty. The effect of the foam, actually, was that of a gigantic, slavering, blind gullet straining to devour. It moved erratically over the surface. Terry called to Deirdre, "Have Nick tell the flattop that the foam only comes up from deep water. If they can get inside the hundred-fathom curve they're safe! Maybe even five hundred. Maybe more. But the foam only comes up from deep water!" The mine layer came on from the horizon at topmost speed. Apparently, they had received warning from the carrier, because the ship suddenly began to zig-zag. The carrier itself adopted the unpredictable change-of-course system which had been originally designed to frustrate submarines lying in wait. Both ships adopted it just in time. A ravening area of foam appeared directly before the mine layer's bow just as she turned aside. The mine layer dumped a mine. Terry saw it go overboard. But it would have five miles to sink before it hit bottom. Terry called Davis and jerkily explained that the mines would have to be armed when they went overboard--set so that they would explode when they hit bottom. He explained that depth-bombs might be useful against squids, but if they went off at a fixed depth they would be harmless against the enemy which deployed the squids. The carrier, in the middle of a ninety-degree zig-zag turn, found her bow projecting into a foam-patch. The bow sank deep. The carrier's propellers were out of the water as her bow pointed downward. Had the foam stayed still for two seconds, the carrier would have slid into the column of gigantic ascending bubbles and plunged to destruction. But the foam swerved sidewise. The carrier escaped, and was infinitely cautious after that. She made short, swift, unpredictable dashes this way and that.... Her anti-aircraft guns rumbled and rattled at things upon the surface. Presently, her depth-finder discovered an underwater extension of the island's mountain-foundation, and the ship took refuge where the water was less than a hundred fathoms deep. There she lay, shooting off planes and retrieving them, her guns flashing at whatever targets appeared. Twice, as it happened, snaky, monstrous arms flung themselves up and heaved at the flattop as if the giant squids hoped to overturn even an aircraft carrier by their weight. But those arms were blasted to nothingness. The only damage they did was that a twenty-foot section of tentacle--writhing independently on the flight-deck--broke the landing-gear of a returning plane which collided with it.