So, warding them off as best he could with one hand, he turned sharp to the right and groped his way around the wall of the grotto with his other hand.

Finally he came to an opening, which he entered at once. Of course it might be that he had completely circumnavigated the cave, and that this was the same tunnel through which he had entered. Even so, it would be better to return to the ledge and the river, than to be overwhelmed by this rapidly augmenting swarm of pterodactyls. But no, it was not the same tunnel, for it did not grow smaller as he progressed; so, after frantically beating at the bat-like creatures with both hands for a moment, he crossed his arms Boy Scout fashion in front of his face and fled precipitately down the corridor.

This way proved to be practically straight. His outstretched hands prevented any collision with the walls or other obstacles, which otherwise must inevitably have occurred in the pitch darkness. Cabot was not quite as helpless in the dark as most earth men would have been, for he had over three years of experience with the inky, starless Porovian nights.

As he ran on, his tormentors gradually dropped behind him, until finally they were reduced to only two or three more determined members of the breed.

Cabot accordingly slowed down to a walk. But, just as he did so, one of his feet stepped out into nothingness. With a despairing effort he strove to throw his body backward to safety. He reached out his hands to the sides and then above, groping madly for some support. But all in vain; for, after toppling for it seemed ages on the brink, he pitched over headlong into space—

And struck the surface of a body of water with a resounding splash within a few feet below where he had been standing. The unexpected impact quite took his breath away. He struggled feebly on the surface and groaned until the air flowed into his lungs again. But his relief was supreme at this anticlimactic ending of his fall into an imagined abyss.

When he had fully regained his breath, he struck out for where he thought the shore to be, and was just getting up a good headway when he ran full on into a large, soft, animate form floating idly on the surface. Instantly this creature ceased being idle, and became a thing of action. With a prodigious splashing, it went for Cabot, who warded it off with his hands and feet. He had no idea what it was that he was fighting, but it seemed like several huge rubber windmills. Back, ever back, it forced him, until finally a long snout got by his guard, and two toothless gums closed upon his abdomen, and dragged him beneath the water.

Cabot was an expert swimmer. He had even saved lives on earth. And he knew that the best possible tactics to use when a drowning person drags you under, is to swim down, down, until your incubus lets go in terror. Such tactics, of course, would not work on a subaquatic creature, but the chances were about even that the beast which held him in its deadly grip was an air-breathing denizen of the surface. At any rate, it was worth gambling on, so Cabot struggled downward instead of upward.

This action seemed to puzzle the beast, for it resisted a few moments, then floundered undecidedly, and then let go. Swimming far out to one side, Myles shot upward to the air, and again struck out for the shore. A few short strokes brought him to a ledge, where he hung for a moment to catch his breath. In fact, he would have hung there a little longer than he did, had not a cold and slimy form, brushing across his back, recalled his attention to the perils of the deep.

With a kick of his feet, he chinned himself up to the level of the ledge, bent up one elbow after the other; and then, leaning far inland, threw up his right leg onto the ledge. He was now completely out of the water, except his left leg, which too would be out in another instant. But just at this moment an eel-like body wrapped itself around his left ankle, and began to pull him back into the stream.