A tremendous elation filled McKegnie--until it occurred to him that his shots might have been heard outside. At once he ran and looked at the teleview view screen, and what he saw on its silver surface took all the triumph abruptly out of him. The octopi outside were darting about with alarming activity; a whole cluster of them was centered at the exit port, and, even as the cook stared, the preliminary sounds of opening it came to his ears. "Now I _got_ to run this ship!" he groaned. * * * * * He peered at the mass of levers and wheels, put out a hand, closed his eyes, hesitated, and pulled one of them back. Nothing happened. He tried another. The noise below grew, but still the _NX-1_ remained motionless. Desperate, the cook jerked several other levers. The whine of electric motors surged through the silence; the submarine shuddered and slewed off to the right, as if trying to dig into the sea-floor. "I got it started!" he cried. He did something else. The _NX-1_ stuck her bow dizzily up and sped into the misty-blue realm above in a grand, sweeping circle. The sea-floor with its mound-buildings and swarming octopi fell away behind with a rush. "There!" muttered the triumphant cook. "But--how did I do it?" The submarine was rising like a sky-rocket. McKegnie remembered suddenly that Wells had said the cavern was only a few miles high; he must now be very near the top. He held his breath while he pushed a likely looking lever the other way. He was lucky. The _NX-1_ capered like a two-year-old, kicked up her stern and bolted eagerly for the depths once more. Again the floor of the cavern rushed up at him, again he pulled the potent lever back, and again the submarine meteored upward. This procedure went on for some time. McKegnie was only running an elevator. Was he doomed to dash up and down between floor and ceiling forever? He gave forth pints of sweat, now and then groaning as the submarine grazed horribly close to top or bottom. The dead octopus at his feet slithered limply around on the crazy-angling deck. "I can't keep this up forever!" the cook said peevishly. "Now, what the hell's this thing for?" * * * * * He turned it, and the _NX-1_ tilted in one of her dives and raced forward, midway between ceiling and floor. Her navigator relaxed slightly. He had found the major controls; at least he had been able to stop his dizzy game of plunging up and down. Then, just as he was beginning to wonder where he could go, a large red spot glowed at the edge of the location chart. "Oh, Lord!" he cried. "That's the other submarine--an' it's comin' after me!" Evidently it was, for the red spot rapidly approached the green one. The paralyzing ray tingled, and a moment later the enemy's huge bulk loomed on the teleview screen, a band of violet light spearing from one of her jutting knobs.