they've kept you prisoner and they'll keep me, too—but probably they don't think that's any terrible hardship for us. And they don't realize how much we want to get free."

"What will we do then?" Beddoes broke in impatiently.

"When I see the leader again I've got to get it over that we want to be released. It's a better risk than killing this guard, anyway. They're disposed to be friendly; but if you killed one there'd be the devil to pay." Ken paused, and his eyes closed. He said wearily:

"But, I'm dog tired; no sleep for twenty hours. Let me sleep an hour or two; my head'll be much clearer and we'll talk it over."

Chanley Beddoes said nothing. Ken yawned and stretched his body as comfortably as he could on the slime-coated rocks. Dazed from the rush of amazing events his eyelids closed at once, and soon his breathing settled into a regular beat.

Perhaps half an hour later, a shape moved in the dank gloom of the underwater cavern. The top plane of water rippled softly; little wavelets eddied against the rocks and whispered as the shape slipped down underneath. Then there was silence, no movement; and the water again calmed into a black sheet, smooth as glass. For minutes it stayed so, while Ken's deep, regular breathing stirred the air.

Then suddenly the water's calm was broken. Through its rippling waves the shape reappeared, rivulets streaming from it. Quickly hauling itself up on the rocks, it clambered towards the sleeper. For a moment it paused; then its helmet swung back, revealing Chan's tense, pale face. A hand reached out and gripped the sleeper's arm. A voice called:

"Ken! Wake up! Hurry!"

Even as the words reverberated in the close bowl, the black mirror of water stirred once more. Something pierced through and drifted idly on the surface. It was a large brown-skinned shape, apparently lifeless.

"Ken!" called Chan anxiously again.

The first torpooner stirred. Out of the depths of slumber he mumbled:

"What's the matter?"

"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.

The seal-men passed by—two sleek, blubbery shapes, flipper-arms and legs weaving gracefully, bodies rolling slightly, eyes apparently directed ahead. Close!

They had escaped that time, but there was a disturbing thought in Ken's mind and in Beddoes' too, perhaps—as they resumed their slow-motion flight down the second corridor. "What if those two were going to visit us in the cell-chamber? Once they see the dead guard, hell sure will start to pop!"

For a period that seemed to be measured in hours they fought their way forward through the retarding pressure of the water. The corridor described a long curve. They were on the last stretch—and still no pursuit!

"If only the torp's there!" Ken kept exclaiming in his thoughts. "Just that!"

"If only the torp's there!..." Had they come the right way? He had to trust that to the memory of Beddoes. Beddoes, whose mind had clearly been affected by his seven-day nightmare.... He shook his head. He dared not doubt.

They increased their pace a little. Imagination stimulated their weary muscles. The Narwhal! Men of their own kind! Sun and air! Life again! Ken could have shouted when he saw his partner stop and gesture excitedly before a dark spot in the wall. It could be nothing but the entrance to a trap.

He pressed forward, flicking on his flash and making sure by the water-waved beam it threw. But Beddoes was attending to some sight down the corridor; and suddenly he pointed in fright. The first torpooner looked in the indicated direction and saw what was meant.

Approaching was a wave of menacing brown-skinned bodies, streaming swiftly through the passage several abreast. Their escape had been discovered. The blubber-men were coming.

At once Ken acted, pushing Chan into the narrow opening and scrambling after himself. They wormed along for several feet, till they emerged in a large dark chamber at the far end of which was a big circular entrance barred by three great pale stakes. They were certainly in a whale trap.

Rapidly Ken played his flash around, looking for the torp, but it was nowhere visible. To one side was an out-jutting rock with a niche beneath it. It was a promising place and he stumbled his way there, followed by the other.

It was then that a most peculiar feeling came over him, a feeling that was instantly a surge of panic. Something else was in the trap! His flash arced around and up, and what lay revealed in its ray caused cold shivers to run down the backs of the two men.

Above them, just over the three-toothed outer entrance, hung a black, sleek body, white-striped. Head-on it was, and motionless, eyeing them. A killer whale—alive!—and poised for a lunge!

It barred the way to the outer entrance. They could not retrace their steps; already the round brown head of a blubber-men showed in the inner entrance. They were trapped, front and rear, and confronted by the deadliest animal in the sea.

A second they watched it, frozen immobile; then the whale's great body curved and its flukes went up, and by purest instinct the