For answer, the commander dropped them the last five hundred feet. The sea-floor rose like a gray ghost. More control studs were pushed; the order-board below read: "All Power Off, Rest in Trim." The location chart told a tale that wrung a gasp from Bowman's throat. The red and green lights were practically touching.... The hands of Petty Officer Brown, the helmsman, were quivering on the helm. Wells' fists kept tensing and relaxing as he peered for a sight of the enemy in the teleview. Nothing showed but the moving fingers of spectral kelp. Then both he and Bowman cried out as one: "_There!_" CHAPTER II _The Silent Ray_ A strange shape had suddenly materialized on the screen--an immense, oval-shaped thing of dull metal, with great curving cuts of glass-like substance in its blunt bow, like staring eyes; a lifeless, staring thing, stretching far into the curtain of gloom behind. How long it was, Keith could not tell; at first his numb brain refused to grasp it and reduce it to definite, sane standards of size and length. The cold weeds of the sea-floor kelp beds swayed eerily over and around it. From its bow, he saw, peculiar knobs jutted, the function of which he guessed with dread. Was it waiting with a purpose? Was it waiting--and inviting attack? A frightened whisper from Hemmy Bowman broke the hush: "Keith, the thing has ports, but shows no lights! What kind of creatures can they be?" As he spoke, the three men in the control room felt the unmistakable, jarring tingle of an electric shock. And while their nerves still jumped, it came again; and again. They were conscious of a slight feeling of drowsiness. Keith gaped at Bowman and Brown, and then a flash on the teleview screen drew his eyes. There, against the blackness of its otherwise inanimate hulk, one of the jutting knobs on the bow of the mysterious submarine was glowing and pulsing with orange life! With it came the tingling shock again. It flicked off as they watched, then returned and went once more. "They're attacking, but thank God the shock was harmless!" Wells said grimly. "All right; they've asked for it: I'm going to see how they like the taste of a torpedo!" * * * * * The two submarines were resting on the ocean floor with perhaps two hundred feet between them. The _NX-1's_ bow tubes were not exactly in line to score a direct hit; she would have to be maneuvered slightly to port. The range was short; the explosion from the torpedoes would be titanic. Keith punched the control studs, ordering the men below to assume firing stations. Then, while waiting for the _NX-1_ to shift, he studied the teleview screen to sight the range exactly. The black dot which represented the enemy craft was not directly on the crossed hair-lines of the dial-like range-finder, but shifting the _NX-1_ a few feet would bring it to the perfect firing point. But the _NX-1_ did not budge.