As the young man waited for the winch to get under way on the boat a mile above him, he pulled out his electric pocket flashlight and sent its feeble ray out through his quartz-glass window into the dim royal-purple depths beyond, in one last attempt to get a look at those mysterious fish-shapes which had so intrigued him. And then he saw one of them distinctly. Evidently they had swum closer when the glow of his searchlight had stopped; and so the sudden flash of his pocket-light had taken them by surprise. For, as he snapped it on, he caught an instant's glimpse of a grinning fish-face pressed close against the outside of his thick window-pane, as though trying to peer in at him. The fish-face somewhat resembled the head of a shark, except that the mouth was a bit smaller and not quite so leeringly brutal, and the forehead was rather high and domed. But what most attracted Abbot's attention, in the brief instant before the startled fish whisked away in a swirl of phosphorescent foam, was the fact that, from beneath each of the two pectoral fins, there protruded what appeared to be a skinny human arm, terminating in three fingers and a thumb! Then the fish was gone. Abbot snapped off his little light. The diving-sphere quivered, as the hoisting-cable tautened. But suddenly the sphere settled back to the bottom of the sea with a jarring thud. "Cable's parted, sir!" spoke a frantic voice in his ear-phones. * * * * * For a moment George Abbot sat stunned with horror. Then his mind began to race, like a squirrel in a cage, seeking some way of escape. Perhaps he could manage to unscrew the 400-pound trap door at the top of the sphere, and shoot to the surface, with the bubbling-out of the confined air. But his scientifically trained mind made some rapid calculations which showed him this was absurd. At the depth of a mile, the pressure is roughly 156 atmospheres, that is to say, 156 times the air-pressure at the surface of the earth; and the moment that his sphere was opened to this pressure, he would be blown back inwardly away from the man-hole, and the air inside his sphere would suddenly be compressed to only 1/156 of its former volume. Not only would this pressure be sufficient to squash him into a mangled pulp, but also the sudden compression of the air inside the sphere would generate enough heat to fry that mangled pulp to a crisp cinder almost instantly. As George Abbot came to a full realization of the horror of these facts, he recoiled from the trap-door as though it were charged with death. "For Heaven's sakes, do something!" he shrieked in agony into the transmitter.