"Without Sparks, I guess I'll have to communicate with you through portable," Keith said, and quickly donned one of the tiny portable sets. "Right. Ready, Keith." Bowman started his awkward, crawling progress up the ladder into the conning tower just above, Keith helping from behind. When they stood before the exit port on the lee side, Wells shot back its bolts and the door swung open, revealing the black emptiness of the water chamber. The commander gazed for a second into Bowman's eyes. The moment had come. Keith turned his head away, felt a hand grip his. He wrung it tightly.... Bowman clumped into the chamber. The commander closed and locked the door, and he heard the streaming water pour in as Hemmy turned the valve. Then Wells sped down the ladder and tilted the diving and course rudders of the submarine. She swayed daintily over to port; held there. A moment later the recurring electric tingle brushed him. Had the enemy seen Bowman leave? Had the ray struck him down? He glared into the teleview. "Thank God!" he breathed. For Hemmy had already slid down the _NX-1's_ smooth hull and was safe on the sea-floor beside her. "Everything right?" Wells asked, speaking into the microphone of his portable. "All O.K.," came the answer. "Going forward now. Kelp thick as hell." * * * * * Keith's eyes bored at the screen. This misshapen monster who was his friend! Almost obscured by bands of thick-leaved kelp the yellow form moved, hands clearing a pathway through the weeds. Slowly but surely he made for the bow of the submersible. "Hard going, Keith. God--the cavern's right ahead!" It was ghostly to hear Hemmy's warm voice from the lifeless solitude outside. Breath coming quickly, Wells watched the silent scene--the cleft in the wall of rock overshadowing everything now. The diver fought ahead, gaining inch by inch. Now, save for occasional clumps of weed, he was exposed to the enemy.... Now the last desperate gauntlet was reached.... Keith felt his blood pound hotly. "I'm gaining, Keith. Gaining...." Bowman had little breath for speech. His tiny form battled on, now sinking from sight as he dropped into some masked gully, now wrestling slowly with great swaying strands of kelp, but always struggling ahead. "I'm at the bow, Keith! The hawser arm's right in our mooring holes. I'll go halfway before fastening the charge. Any signs of life from the devil?" "None yet, Hemmy. But go slow. Hide all you can, old man, for God's sake!..." Right beneath the metal arm, Bowman's dwarfed figure crept doggedly ahead. Forward, inch by breathless inch. Kelp thickened, washed away; the two hulking submersibles, captor and captive, surged onward--but just a little faster went the valiant figure with the black charge on its back. The towing monster had its snout in the cavern. The darkness thickened. Bowman was quarter way! He plunged desperately. Half way! "I'm there, Keith! Now for it!"