Wells turned to meet Bowman's inquisitive face. He quickly repeated the gist of Knapp's weird story. "We saw them at dusk, last evening--remember? And now they're gone, destroyed. What can have done it?" For some minutes the two surprised men speculated on the strange occurrence. Then Knapp's voice again rang in the headphones. "Wells? My God, man, this is getting downright fantastic! We've just taken two survivors on board; one's barely alive and the other crazy. I can't get an intelligible thing from him; he keeps shrieking about writhing arms and awful eyes--and monsters he calls 'machine-fish'!" "You're sure he's insane?" Robert Knapp's voice hesitated queerly. "Well, he's shrieking about 'machine-fish'--fish with machines over them!... I--I'm going to broadcast the whole story to the land stations. 'Machine-fish'! I don't know.... I don't know.... You'd better hurry back, Wells!" He rang off. * * * * * Keith slipped off the headphones and told Bowman what he had learned. Hardy, staunchly built craft, those fishing boats were; born in the teeth of gales. What horror could have ripped them--all of them--to driftwood, with the weather perfect? And a half-mad survivor, raving about "machine-fish"! "Such things are preposterous," Bowman commented scornfully. "But--the fleet's gone, Hemmy," Keith replied. "Anyway, we'll speed back, and see what it's all about." He punched swift commands on the control studs. "Empty Tanks, Zoom to Surface, Full Speed," the crimson words glared down below, and the _NX-1_ at once shoved her snout up, trembling as her great electric motors began their pulsing whine. The delicate fingers of the massed dials before Keith danced exultantly. The depth-levels tolled out: "Seven thousand ... six thousand ... five thousand--" "Keith! Look there!" Hemmy Bowman was pointing with amazement at the location chart, a black mesh screen that showed the position of other submarines within a radius of two miles. In one corner, a spot of vivid red was shining. "But it can't be a submarine!" Wells objected. "Our reports would have mentioned it!" The two officers stared at each other. "'Machine-fish!'" Bowman whispered softly. "If there were machines, the metal would register on the chart." "It must be them!" the commander roared, coming out of his daze. "And, by God, we're going after them!" * * * * * Rapidly he brought the _NX-1_ out of her zoom to the surface, and left her at four thousand feet, in perfect trim, while he read the instruments closely. A green spot in the center of the location chart denoted the _NX-1's_ exact position. A distance of perhaps forty inches separated it from the red light on the meshed screen--which represented, roughly, a mile and a half. Below the chart was a thick dial, over which a black hand, indicating the mysterious submersible's approximate depth, was slowly moving.