"We've got to shove off right now! Quick! Put on your helmet!" Kenneth Torrance sat up and peered through half-open eyes. He saw before him the face of Chanley Beddoes, wild and excited. In one hand he held the steel crowbar. And behind, on the surface of the water, floated the motionless body of a blubber-man, its head beaten in, streamers of red trailing from it. Ken said sharply: "You killed him? After what I told you? You fool!" "Yes, I killed him!" Beddoes answered brazenly. "What of it?" Ken said nothing for a moment. Bitter reproach trembled on his tongue, but he did not speak the words, for Chan's mind was all too clearly on the thin line this side of insanity. He only said: "Well, you've forced the issue, and we've got to leave immediately. It may mean our death, but let's forget it. Now--how much of your air-units is left?" "About two hours. I lost a lot through a leak." Ken took half of his own store of the little cells from his helmet. "I'll share mine. That'll give us both sixteen hours all told--in case we don't find your torpoon. You're sure they killed the whale in that trap? And you know the way?" "I think so," said Beddoes excitedly. "You follow me." "All right. On helmets, then." The clasps were fastened down, cutting them off from spoken communication with each other. Ken took the hand-flash and crowbar and stuck them in his own belt, and both clumsy, grotesque figures splashed into the water, vanished beneath its surface and ducked under the shadowy body of the dead blubber-man. Below, in the dim quarter-light, Ken peered out of the entrance to the cell chamber. The corridor seemed safe, there being only the distant colored streaks of light-fish, and occasionally even these disappeared, leaving heaped shadows in the darkened water. He nodded to Beddoes and boldly they began their flight. Their progress was nerve-rackingly slow, in spite of their utmost exertions. The water that retarded them at times contained unsuspected currents that destroyed their equilibrium and sent them stroking madly with both hands to regain it. Far different, this, than the swift, effortless swimming of the blubber-men. Their weighted feet stumbled often on the floor of the passage, and several times they lost balance and fell towards the sides. Each time that this happened Ken was struck with the fear of ripping the fabric of his sea-suit. And all the time there was the apprehension of imminent discovery. At last he saw Beddoes wave an arm and enter a dim cleft a few feet ahead in the left side of the wall. In turn he floundered through--and just in time. From around a bend in the corridor shortly ahead there came two blubber-men. In only a few seconds they would pass the niche the two humans had entered. Crowbar ready, Ken flattened himself against the sidewall, pulling his companion back with him. They waited. * * * * *