He took the spear she handed him, and sank once more. Again something moved in the deeper part of the lagoon. It was a fretful motion, as if a creature or creatures tried to burrow away from the light shining through the water. Whatever moved, a thick cloud of debris from the bottom floated all the way up to the surface. Terry came up for air. "There's something queer there," he said shortly. "I don't know what." He went under and swam cautiously nearer to the disturbance. He was within a few feet of the curling cloud of obscurity when something like a gigantic worm came out of it. Or maybe it was like an elephant's trunk, only no elephant ever had a trunk so huge. It was a dull and glistening writhing object. Its end was rounded. The tip of the worm-like thing must have been a foot in diameter, and it came out of the mud cloud for four feet, then six, then, fifteen feet. It thickened only slightly in that length. It groped blindly in the brightness. Terry swam back quickly, and the object reared up and made a groping sweep through the clear water. Some peculiar white disks suddenly appeared on the underside of the long tentacle. They looked like sucker-disks, able to grip anything at all. The monstrous tentacle fumbled for Terry, as if guided by the pressure-waves his movements generated. Terry froze. Deirdre moved in the boat almost directly overhead. Something clanked in the boat and he heard it. The boat was probably rocking, making the pressure-waves that a creature from the abyss would depend upon for guidance where eyes would not serve at all. The thick, bulging tentacle reached toward the sound at the surface, now ignoring Terry, though he was nearer. He was still. The white sucker-disks on its under side had several rings of a horny, tooth-like substance at their rims. The smallest were about four inches wide. The fumbling object felt blindly in the water. Deirdre stirred again in the boat. The visible portion of the groping monstrosity was already longer than the boat. The whole creature would be enormous! If this groping arm rested upon the gunwale of the boat, it could easily swamp it. It groped for the boat, coming horribly out of a cloud of mud. It reached out. In another instant it would touch.... Terry plunged his fish spear into the worm. It jerked violently. There were enormous thrashings. Other similar white-disked arms thrust into view, fumbling somehow angrily for the creature--Terry--which had dared to attack it. He darted for the surface. Something unspeakably horrible touched him, but it was the smooth and not the suckered side of the groping worm. Terry's head was now above water. He grasped the gunwale to pull himself in, in a fever of haste. But the thing that had touched him before came back. It grazed his leg, for just a second. Where it touched, his flesh burned like fire. "Start ... motor!" gasped Terry. "Get away!"