Sleepily the lookout stared at the scope-screen before him, wishing for something that would break the monotony of the scene it pictured: the schools of ghostly fish fleeting by, the occasional shafts of pale sunlight filtering down through breaks in the ice-floes above, the long snaky ropes of underwater growth. None of this was conducive to wakefulness; nor did the half-speed drone of the electric engines aft and the snores of some distant sleeper help him. The four other men on duty in the submarine--the helmsman; the second mate, whose watch it was; the quartermaster and the second engineer--might not have been present, so motionless and silent were they.

The lookout man stifled another yawn and glanced at a clock to see how much more time remained of his trick. Then suddenly something on the screen brought him to alert attention. He blinked at it; stared hard--and thrilled.

Far ahead, caught for an instant by the submarine _Narwhal’s+ light-beams, a number of sleek bodies moved through the foggy murk, with a flash of white bellies and an easy graceful thrust of flukes.

The watcher’s hands cupped his mouth; he turned and sang out:

“K-i-i-ll-ers! I see killers!”

The cry rang in every corner, and immediately there was a feverish response. Rubbing their eyes, men appeared as if from nowhere and jumped to posts; with a clang, the telegraph under the second mate’s hand went over to full speed; Captain Streight rolled heavily out of his bunk, flipped his feet mechanically into sea-boots and came stamping forward. First Torpooner Kenneth Torrance, as he sat up and stretched, heard the usual crisp question:

“Where away?”

“Five points off sta’b’d bow, sir; quarter-mile away; swimming slow.”

“How large a school?”

“Couldn’t say, sir. Looks around a dozen.”

“Whew!” whistled Ken Torrance. “That’s a strike!” He pulled on a sweater and strode forward to the scope-screen to see for himself, even as Captain Streight, all at once testy with eagerness, bawled:

“Sta’b’d five! Torpoon ready, Mister Torrance! Mister Torr--oh, here you are. Take a look.”

Never in the two years of experience which had brought him to the important post of first torpooner had Ken failed to thrill at the sight which now met his eyes. Directly ahead, now that the Narwhal’s bow was turned in pursuit, but veering slowly to port, swam a pack of the twenty to thirty-foot dolphins which are called “killer whales,” their bodies so close-pressed that they seemed to be an undulating wave of black, occasionally sliced with white as the fluke-thrusts brought their bellies into view. Their speed through the shadowed, gloomy water was equal to the submarine’s; when alarmed, it would almost double.

“Three more of ‘em will fill our tanks,” grunted Streight, his chunky face almost glowing. He bit on a plug of tobacco, his eyes never moving from the screen. “Now, if only we hadn’t lost Beddoes ... Y’ think you can bag three, Mister Torrance?”

“Well, if three’ll fill our tanks--sure!” grinned Ken.

The other’s eyebrows twitched suddenly. “They’re speeding up!” he shouted, and then: “That torpoon ready, there? Good.” His voice lowered again as Ken pulled his belt a notch tighter and snatched a last glimpse of the fish before leaving. “I want you to try for three, son,” he said soberly: “but--be careful. Don’t take fool chances, and keep alert. Remember Beddoes.”

Ken nodded and walked to the torpoon catapult, hearing Streight’s familiar send-off echoed by the men of the crew who were nearby:

“Good hunting!”

The idea of an underwater craft for the pursuit of killer whales--tremendously valuable since the discovery of valuable medicinal qualities in their oil--had been scoffed at by the majority of the Alaska Whaling Company’s officials at the time of its suggestion, but the Narwhal after her first two months of service had decisively proved her worth. She was not restricted to the open seas, now swept almost clean of the highly prized killers; she could follow them to their last refuge, right beneath the floe-edges of the Arctic Circle; and as a result she could bring back more oil than any four surface whalers.

With a cruising radius of twenty-five hundred miles, she stayed out from the base until her torpoons had accounted for anywhere from sixty to eighty killers. One by one these sea-animals would be taken to the surface and there cut up and boiled down, until her tanks were full of the precious blubber oil. Ever farther she pressed in her quest for the fish schools, dipping for leagues into a silent sea that for ages had been known only to the whale and the seal and their kindred; a sea always dark and mysterious beneath its sheath of ice.

The inner catapult door closed behind Kenneth Torrance, and he slid into his torpoon. Twelve feet long, and resembling in miniature a dirigible, was this weapon that made practical an underwater whaling craft. The tapered stern bore long directional rudders, which curved round the squat high-speed propeller: its smooth flanks of burnished steel were marked only by the lines of the entrance port, which the torpooner now drew tight and locked. Twin eyes of light-beam projectors were set in the bow, which was cut also by a vision-plate of fused quartz and the nitro-shell gun’s tube, successor to the gun-cast harpoon.

Ken lay full-length in the padded body compartment, his feet resting on the controlling bars of the directional planes, hands on the torpoon’s engine levers. A harness was buckled all around him, to keep him in place. His gray eyes, level and sober, peered through the vision-plate at the outer catapult door.

Suddenly a spot of red light glowed in it; the door quivered, swung out. A black tide swirled into the chamber. There came the hiss of released air-pressure, and the slim undersea steed rocketed out into the exterior gloom, her light-beams flashing on and propeller settling into a blur of speed as she was flung.

Ken turned on her full twenty-four knots, zoomed above the dark bulk of the slower mother ship, whose light-beams flashed across him for a second, and then straightened out in a long, slight-angled dive after the great black bodies ahead.

Aware that some strange enemy was on their track, the killers had become panicky and were darting away at their full speed, which was only slightly under that of the torpoon’s humming motors, and which at times even surpassed it. Ken saw that it looked like a long chase, and settled his lean body as comfortably as he could.

His mind was not concentrated on the task ahead, for the first part was mere routine and he could follow his quarry almost mechanically. And so, as his steel shell drove through the ever-shadowed, icy sea, he began to think about the disappearance of Chan Beddoes, the Narwhal’s second torpooner.

Dead, now Beddoes; it was a week since he had set out on the chase from which he had never returned. Ken could only conjecture as to what had stricken him down. There were countless possibilities: perhaps a blow from a dying killer whale’s flukes bursting his torpoon’s seams; perhaps a crash into underwater ice. Whatever it was, it had been sudden, for not even a faint radioed S.O.S. had trembled into the ear-phones of the Narwhal’s radio-man. For two days they had held hopes that the second torpooner still lived, as the sea-suit stored in each torp contained air-units sufficient for thirty-six hours. But a whole week’s passing told them that that vast stretch of glacial sea was now Chan Beddoes’ grave.

Ken’s reflections brought an urge to get the present job over with as quickly as possible. He squeezed another ounce of speed from the torpoon, taxing it to the limit and setting up a slight vibration; then he fondled the nitro-shell gun’s trigger and studied the huge fish bodies ahead.

“Seems as if they’re going to run forever,” he muttered indignantly. “We’ll be to the Pole if they keep it up!”

Already the Narwhal was miles behind. Through the torp’s vision-plate a scene of ever increasing mystery and gloom met his gaze. The killers’ course had brought them beneath a wide sheet of ice, apparently, for there were no more columns of pale sunlight piercing through. The quarter-light monotone was unbroken, save by deeper drifts of shadow, and as he drummed through it the torpooner wondered at its lifelessness. He discerned no more of the ghostly fish-schools that usually abounded. Some enemy possibly had driven them from the region; but not the whale he was pursuing, for they scorned such fare.

He was scanning the surrounding murk apprehensively, when, of a sudden, his brain and body tensed.

Off to one side, far to the right, he thought he had glimpsed a figure. It was hanging motionless, level with him; and at first it looked like a seal. But the flippers seemed longer than a seal’s; moreover, no seal would be anywhere near a pack of killer whales; nor did they poise in an upright position. It couldn’t be a seal, he told himself. What, then? Was it only imagination that made it appear faintly human-shaped?

He strove to catch it again with staring eyes, but it was gone, leaving only a jumbled impression of something fantastic in his mind, and the next instant the whole thing was forgotten in the movements of the killer school, now only a few hundred yards ahead.

They suddenly began a great sweeping curve to the right, a typical maneuver before standing for attack or breaking up. At once Ken swerved to starboard and drove the torpoon’s nose for an advance point on the circle the fish were describing. His move swallowed the distance between them; the sleek, thick-blubbered bodies swept close by his vision-plate, their rush tossing the torp slightly. Twelve of them went past in a blur, and then came the thirteenth, the invariable straggler of a school. The thin light-beams pencilled through the darkness, outlining the rushing black shape; Ken gripped the gun’s trigger and jockeyed the torp up a trifle in the seconds remaining, always keeping the sights dead set on the vital spot twelve inches behind the whale’s little eye.

When only fifteen feet separated them he squeezed the trigger and at once zoomed up and away to get clear of the killer’s start of pain and, if the shot were true, its following death flurry.

The shell slid deep into the rich outer blubber; and, wheeling, Ken watched the mighty mammal quiver in its forward rush. This was merely the reaction from the pain of the shell’s entrance; the nitro had not as yet exploded.

Now it did. The projectiles carried but a small charge, in order not to rip too much the buoyant lungs and so cause the body to sink, but the killer trembled like a jelly from the shock. The heart was reached; its razor-sharp flukes thrashing and tooth-lined jaws clicking, the killer wheeled with incredible speed in its death flurry. A minute later the body shuddered a last time, then drifted slowly over, showing the white belly. It began a gentle rise up toward the ceiling of ice.

“One!” grinned Ken Torrance. He noted his position on the torpoon’s dials and gave it to the Narwhal by radio. They would then follow and pick up the whale.

“I’ll have the second in ten minutes,” he promised confidently. “Signing off!”

Again the torp darted after its prey.

He found it easy, this time, to overhaul them. Not many minutes had elapsed before he again caught sight of their rhythmically thrusting flukes and the flash of white under-sides. Unaware that one of their fellows had been left a lifeless carcass by the steel fish again nearing them, they had reduced their speed somewhat.

Ken angled down a hundred feet into the deeper shadows, not wanting to apprise them of his presence. He continued at that level until the belly of the rearmost whale rolled white above him; then he veered off to the left, rising as he did so, in order to bring his assault to bear directly on the killer’s flanks.

He swung back and streaked in for the kill. It looked like an easy one.

But he was never more mistaken in his life. For, as luck had it, he had chosen a tartar, a fighting fish--literally the “killer” which its kind had been named.

The torpooner knew what he was in for as soon as he fired his first shell. Its aim was bad, and instead of sinking into the flesh it merely ripped across the whale’s back, leaving a ragged, ugly scar.

An ordinary whale would have been scared into panic by the wound and doubled its speed in an effort to get away; but Ken Torrance saw this one wheel its six-foot snout around viciously until its beady little eyes settled on the torpoon.

“I’ll be damned!” he muttered. “He’s turning to fight. All right, come ahead!”

He veered about and fired another shot that missed its mark by feet, but creased the whale’s flukes. At once this terrible weapon lashed titanically up and down, and thirty feet of berserk killer came curving towards the lone man inside his shell of steel. Ken tensed himself for combat. He would have to keep a good distance from the fish and fire until he got it, as a square smash from its flukes might crumple the torp like an egg-shell.

[Illustration: _Thirty feet of berserk killer came curving towards the lone man_.]

But his foe gave him no chance. Crazy with pain and anger, it swept up and nipped his dive for the bottom with a fluke-blow that tumbled the torpoon over and dazed its pilot. Before he could get straightened out it was on him again, catching him up into a wild whirlpool, butting the shell and flashing round to get its flukes into position. With a wrench, Ken jammed the rudder over, shoved his accelerator flat, and got free just as the tail thrashed down. He was breathing hard and sweating as he banked around--to see once more the whale, its wicked jaws wide open, charging directly at him.

For a moment he was unable to move. Such a mode of attack was totally unexpected, and the sight held him fascinated. He could see the very wrinkles of the monster’s skin as it rushed in, with shadowy flukes thrusting behind; could see the lines of dagger-like teeth, the cavernous maw and gullet. And then all vision was blotted out as the jaws closed around the torpoon’s nose.

Ken did not wait for those jaws to crunch shut. He gripped the nitro-shell gun’s trigger and squeezed it back.

The weapon hissed, flung its shell. He reversed his engines to try and tear free. Seconds dragged by with no result. Then he felt a mighty jolt; his harness broke; and he was pitched into the torp’s engine controls.

That was all he knew, save for a vague feeling of falling, falling over and over, which was ended when a second bone-shaking shock brought complete oblivion...

It was darkness that met his eyes when they opened, the eery darkness of the floor of the Polar Sea.

Darkness! Half-conscious as he was, he started in surprise. He looked for the torp’s shaded control board-lights, but could not find them. Bewildered, he wondered what had happened, and then remembered the whale. In its flurry it had smashed him down.

Pain was thumping his forehead where he had struck the control levers; with a groan he twisted his body around and felt for his hand-flash. At any rate, there was no water inside the body compartment. The seams had resisted the blow. But why were there no lights?

He found his hand-flash, and its beam showed him the reason. Playing it on the small water-tight door which separated the main compartment from that in which the machinery was contained, he looked through its fused quartz peep-hole. He gaped in consternation.

There was, after all, a leak in the torpoon’s shell, and a bad one. The machinery compartment was full of water.

“Gosh!” he muttered. “That means no light, no radio--no power! Guess I’m stranded!”

He considered the situation. It was not serious, for he had been in touch with the Narwhal after bagging the first whale and had given his position. The submarine would proceed to the kill immediately; then, after a while, not hearing from him, they would scour the neighborhood, just as they had hunted for Chan Beddoes when he did not return.

But they’d find him, Ken told himself--and soon. He had no idea how long he had lain unconscious, but probably by now the mother ship had already hooked onto the first whale; maybe she was already hunting for him.

“Well, I’d better get out and be ready to signal to ‘em with the flash,” he reflected. “They may miss me here in the mud.”

Taking his sea-suit from a long narrow locker, he drew the stiff-woven fabric over his body, turned the air-units on, clamped the face-shield shut, and then, gripping his hand-flash, slowly opened the port in the shell’s side.

A weird figure he was, fit for the mysterious gloom into which he came. With casque of steel and lead-weighted feet, staring face-shield and metal belt, and equipped with a knife and two or three emergency tools, the sea-suit transformed him into a clumsy, grotesque giant. He sloshed into the muddy sea bottom, stumbling at first from the heavy water resistance and hardly able to see anything. The torpoon itself was a hazy blur at a short distance, but up above the light was better, being almost bright next to the ice ceiling. He adjusted the air pressure inside his suit, floating his feet off the bottom. A few clumsy armstrokes and he went drifting gently upward.

Knowing that the “bends”--bubbles of air in a diver’s veins--come from too rapidly changing pressures when rising, he made his ascent carefully. Up twenty feet, then a pause; twenty feet more and another pause. So he rose some ninety feet, and finally arrived at the underside of the ice floe.

Here he found the water a pale blue-green, increasing, at the limit of his vision, to impenetrable black. Nearby was a great dark blur which he recognized as the killer whale that had struck him down. It bobbed lifelessly against the smooth, light ceiling of ice. Slowly, he swam over towards it.

There was no mark of the havoc his last shot must have wreaked inside. He examined the body with interest, fingering the two inch-long teeth, which even the mighty sperm whale fears and flees from.

“Pretty wicked,” he said aloud, just for the companionship of his voice. “And there’s a lot of oil in this brute. Streight’ll be glad to get him. Maybe he won’t need a third to fill the tanks.”

Thought of his captain made him look up and around, hoping to see the Narwhal’s light-beams come threading through the distant murk. He did not see them, but what he did see caused his mouth to drop open, and his veins to chill with a cold that was not that of the sea nor the ice above.

“Good Lord!” he whispered. “That thing--again!”

Like a specter from the deep, some hundred feet away was a form, seal-like in appearance, yet not wholly seal. It poised there motionless, apparently looking straight at him.

Fear came over Ken as he studied it. Its body was perhaps ten feet long, and sleek and fat under a brown-colored hide. But its flippers were not those of a seal; they were too long and slender, especially the hind ones. They unquestionably bore a remote resemblance to human arms and legs.

“Yet it can’t be anything but some kind of seal,” Ken whispered to himself. “It must be!”

But then, too, it did not have the ordinary seal’s bullet head, set squat between smoothly tapering shoulders, but rather something bulbous, half like that of a man, in spite of the layers of fat that stream-lined from it to the broad shoulders. It did have, however, two large, staring eyes, and slitted holes inches below them for nostrils--which showed that it breathed air and was therefore warm-blooded.

Quite motionless, each stared at the other, while minutes passed. Then the creature moved slowly up and forward, impelled by a graceful and hardly perceptible roll of its queer flippers. Very gradually it came towards Kenneth Torrance; and he, peering with fear-tinged curiosity at the animal’s bold advance, saw two creases of fat that must have been lips slide open in the smooth brown face, baring strong, pointed teeth.

Not knowing whether it was an attack or merely inquisitiveness, he unsheathed his knife. At this the figure stopped and poised motionless again, perhaps fifty feet away, and after a moment turned its sleek head first to the left and then to the right. Automatically, Ken gazed around likewise. He drew in his breath with a sharp hiss.

Like shadows, additional figures had appeared in the distant murk. Silently they had come; he could see eleven--twelve--even more. He was surrounded! No longer doubting their purpose, he gripped his knife firmly. He knew he could never get down to the torpoon in time.

And then the circle began to close.

There was little he could do to resist them, he realized, for what he had seen of their movements told him that they were swift, effortless swimmers. But he braced himself as best he could against the dead whale, to protect his back. He would at least go down fighting.

As their spectral shapes slid slowly closer he noted something that had escaped his eyes before. Four or five of them were holding dim objects in their arm-like flippers. Spears, he made them out to be, rudely fashioned from bone. And others held dark-colored loops, which they were slowly forming into nooses.

“They’re intelligent, all right,” Ken muttered. “Spears--of whalebone, I guess. And ropes--probably seaweed. Weapons! Good Lord, what kind of seals are these?”

Easily, gracefully, the silent circle drew in to perhaps twenty feet of him, where they paused again, hanging motionless at regular intervals in the eery, wavering half-light. Ken licked his lips nervously. Then the one whom he had seen first moved its head slightly, in what was apparently a signal. And in a concerted movement, so bewilderingly rapid that his eyes could not hold them, they rushed him.

He had expected speed, but not speed such as this. He had barely swung his knife-arm up when the wave engulfed him.

Doubling, curving shapes looped around him; blubbery bodies pressed against him; eyes flashed by in streaks of brown; he knew that he was being tumbled and tossed and that his knife and hand-flash had fallen under the shock of the attack. And then there was a sharper sensation. As he struggled to break free, taut cords trussed his legs and arms like any captive animal’s.

The stream of moving bodies slowed in movement and fell back from a breathless, dazed Kenneth Torrance. He then got his first clear view since the assault was unleashed.

He was upright, many feet away from the killer whale’s carcass, his arms bound strongly to his sides with seaweed-rope, his legs locked close together. To one side he glimpsed several of the creatures fastening other rope strands to the whale’s flukes. When they had finished, with smoothly thrusting flippers they began to haul the carcass forward, and he felt himself move feet first in the same direction.

He forced a wry smile to his lips. “A swell fight I put up!” he grunted. “Hold ‘em off! Yeah--I bet I held ‘em for a full tenth of a second.”

He still could hardly believe what had so rapidly befallen him. It was difficult to credit eyes that showed him creatures whose bodies were mainly seal-like, and yet whose weapons and co-ördinated movements spoke for human intelligence. But they were certainly real. At his feet he could feel the pressure of a guard’s flippers against him.

He was towed in this fashion for some distance when the pressure of the flippers suddenly tightened and he was pulled into a deep-angled swoop toward the sea-bottom below. Previously he had seen his captors’ amazing speed, but now he felt it. Down and down he went, and at last, when it seemed he must crash into the sea floor, his momentum was quickly checked, and he found himself standing in the mud, from which position, lacking support from his guard, he drifted to a horizontal one, face up. And there, lying helpless on the bottom, he saw the reason for the sudden dive. Far to the right, piercing faintly through the murk, were two faint interweaving beams of white that preceded a slowly moving dark bulk.

The Narwhal! Wild hopes of rescue coursed through him.

Dimly, as he watched the beams, he was aware of the rest of the creatures dropping down, guiding between them the whale’s carcass. Then a firm pressure was applied to his side, and he was rolled over, face down in the mud. Unable any longer to see his ship, his momentary vision of rescue vanished.

“Hopeless, I guess,” he muttered despairingly. The darkness on the sea-floor was too thick, the wavering shadows too deceptive. And his hand-flash and knife were gone--probably knocked from his grasp during the struggle, he thought.

He realized that the seal-like animals were lying low until the submarine passed, its size having awed them. The color of the bodies blended perfectly with the gloom, as did that of his own sea-suit. His bonds prevented him from making even the slightest movement to attract attention.

Torturing thoughts raced through the torpooner’s brain. He saw, in his mind’s eye, straight above, a hazy bulk, with shimmering columns of white angling from its nose. His imagination pictured for him the warm, well-lit interior, and the bunks--the coffee steaming on the fire, the men at their posts and Streight’s anxious, beefy face. He saw it all as plainly as if he were inside, cracking jokes with one of the engineers.

The minutes passed. The Narwhal must now be gone. Ken’s cheek muscles stood out as he pressed his teeth together. “Well, go on!” he exploded in impotent rage. “What are you waiting for? Kill me! Eat me if you’re going to!” And he cursed the silent forms around him till his ears hurt from the reverberation.

After the Narwhal had vanished in the gloom, the torpooner’s captors lifted him from the bottom and propelled him leisurely forward again, the slight, graceful roll of their flippers slipping them along smoothly.

A dull hopelessness came over him. No longer could he hope that his submarine would find him. Only one thing was certain, and that was that death would soon come. For even if his captors did not kill him at once, he had but thirty-six hours before his air-units would be exhausted. Certainly, having captured him, the seal-creatures would not release him. And it was too much to expect them to realize that his sea-unit was only an artificial covering which enabled him to live underwater, and not his own flesh and blood.

And as for the chance of breaking loose--the idea was laughable. His speed was snail-like in comparison with theirs. Even if he did manage somehow to get away, what good would it do? How could he, a puny, helpless mite, ever hope to locate the Narwhal in this vast sweep of Arctic sea? His torpoon was wrecked, and he had no means of communication.

His situation was quite hopeless.

Far ahead, a dark shape grew in the foggy murk, and as they neared, spread upwards and outwards. They angled up and up; the sea-floor was higher there. Ken, peering as best he could, made out that the mountainous, looming bulk was the face of a giant underwater mound, whose uneven formation indicated that it was the result of some long-past upheaval. It was the first of a rolling series of such hillocks, six or seven in all, stretching back into the gloom. Their rounded peaks reached to within a few feet of the water’s ice-sheathed surface. Surely the creatures’ home was among these mounds.

He was skirted round the base of the first hillock and caught a glimpse of something in its face which was apparently of his captors’ construction. It was a hole, dark, mysterious, perhaps fifteen feet in diameter, and barring it were three great gray stakes, reaching from top to bottom. Behind the stakes, Ken got a jumbled impression of a body, large and sleek, of black streaked with white, that moved restlessly back and forth in the hole and occasionally seemed to lash out in anger. He wondered what it was. Before long, he knew.

The party of seal-creatures stopped before the second of the row of hillocks. In its face, too, was a hole--a well of blackness--but with no stakes across it. He twisted his head back and saw the carcass of the killer whale he had slain being guided up to the entrance and shoved through. Then, from the upper rim of the hole, three stakes similar to the others he had seen slid down and barred it.

“Storehouses!” he muttered. “Storehouses, I’ll bet anything. And killer whales are their food. They keep ‘em in the holes until they’re needed. But I’ll swear it was a live whale I saw in the first one--and how in the dickens could they capture a mighty killer with their dinky spears and ropes?”

There he had to leave the question, for its answer implied greater intelligence in the creatures than he would admit.

Intelligence--in seals!

And now he was guided smoothly forward to the third hillock, where the leaders of the group glided through a V-shaped cleft in its face. His guards brought him along behind.

A wry smile twisted Kenneth Torrance’s lips. To him, the cleft was more than an entranceway. To him it signified the beginning of the hopeless, lonely end of his life...