"They're sinking to the floor itself," observed Wells. "Perhaps waiting to attack."

The invisible beams from their ultra-violet light-beacons streamed through the silent gloom outside, yet still the teleview screen was empty. Keith punched a stud, and the _NX-1's_ whining motors dulled to a scarcely audible purr.

"What is the thing?" muttered Hemmy Bowman. "G.o.d, Keith, what _is_ it?"

For answer, the commander dropped them the last five hundred feet. The sea-floor rose like a gray ghost. More control studs were pushed; the order-board below read: "All Power Off, Rest in Trim." The location chart told a tale that wrung a gasp from Bowman's throat. The red and green lights were practically touching....

The hands of Petty Officer Brown, the helmsman, were quivering on the helm. Wells' fists kept tensing and relaxing as he peered for a sight of the enemy in the teleview. Nothing showed but the moving fingers of spectral kelp. Then both he and Bowman cried out as one:

"_There!_"

CHAPTER II

_The Silent Ray_

A strange shape had suddenly materialized on the screen--an immense, oval-shaped thing of dull metal, with great curving cuts of gla.s.s-like substance in its blunt bow, like staring eyes; a lifeless, staring thing, stretching far into the curtain of gloom behind. How long it was, Keith could not tell; at first his numb brain refused to grasp it and reduce it to definite, sane standards of size and length. The cold weeds of the sea-floor kelp beds swayed eerily over and around it.

From its bow, he saw, peculiar k.n.o.bs jutted, the function of which he guessed with dread.

Was it waiting with a purpose? Was it waiting--and inviting attack?

A frightened whisper from Hemmy Bowman broke the hush:

"Keith, the thing has ports, but shows no lights! What kind of creatures can they be?"

As he spoke, the three men in the control room felt the unmistakable, jarring tingle of an electric shock. And while their nerves still jumped, it came again; and again. They were conscious of a slight feeling of drowsiness.

Keith gaped at Bowman and Brown, and then a flash on the teleview screen drew his eyes. There, against the blackness of its otherwise inanimate hulk, one of the jutting k.n.o.bs on the bow of the mysterious submarine was glowing and pulsing with orange life! With it came the tingling shock again. It flicked off as they watched, then returned and went once more.

"They're attacking, but thank G.o.d the shock was harmless!" Wells said grimly. "All right; they've asked for it: I'm going to see how they like the taste of a torpedo!"

The two submarines were resting on the ocean floor with perhaps two hundred feet between them. The _NX-1's_ bow tubes were not exactly in line to score a direct hit; she would have to be maneuvered slightly to port. The range was short; the explosion from the torpedoes would be t.i.tanic.

Keith punched the control studs, ordering the men below to a.s.sume firing stations. Then, while waiting for the _NX-1_ to shift, he studied the teleview screen to sight the range exactly. The black dot which represented the enemy craft was not directly on the crossed hair-lines of the dial-like range-finder, but shifting the _NX-1_ a few feet would bring it to the perfect firing point.

But the _NX-1_ did not budge.

Surprised, her commander swung and looked at Bowman. "What the devil?"

he cried. "Did that shock--?" He left the dread thought unfinished and leaped to the speaking tubes.

"Craig! Jones! Wetherby!" he yelled. "Men! Don't you hear me? Aren't you--"

He broke off, wordless, waiting for an answer that did not come, then sprang to the connecting ramp and ran to the deck below.

The scene he found halted him abruptly in his tracks. Every member of the crew was sprawled on the deck, in grotesque, limp postures. They had been standing rigidly at posts, he saw, when the thing, whatever it was, had struck. Without a sound, without a single cry of alarm, the _NX-1's_ crew had been laid low!

The commander slowly advanced to the deck and stared more closely at the upturned faces around him. He saw that every man's eyes were open.

Bending over one still form, he pressed his hand on the heart. It was beating! The man was alive! Amazed, he moved to another and another: they were all breathing, slowly and regularly--were all alive! A curious look in their eyes staggered him for a moment. He could swear that they recognized him, knew he was staring at them--for every single pair was alight with intelligence, and Keith fancied he saw gleams of recognition.

"It must have been a paralyzing ray!" he gasped. "A thing our scientists've been trying to develop for years.... And that monster outside knows the secret...." He lifted an arm of the inert figure at his feet; when he released the grip, it flopped limply back to the deck again.

"_Keith! Come back, quick!_"

Startled, the commander turned to find Hemingway Bowman at the top of the connecting ramp, his face distorted with alarm.

"For G.o.d's sake, come back quick!" he yelled again. "Down there the ray might get you!"

With the words, Wells leaped to the ramp and raced to the control room. He had no sooner made it than he felt again the queer tingle of the electric charge. He found himself trembling. Bowman's face was white. His words came stuttering.

"One second later and they'd have got you.... They got Sparks in his cubby.... You see, the ray doesn't affect us in the control room because--"

"Because the Gibson insulation that protects the instruments keeps it out!" Keith finished grimly. "I see!"

Just then a slight jar ran through the submarine. Coincident with it came a cry from Brown, the helmsman. His arm was pointed at the teleview.

There they saw the enemy's mighty dirigible of metal was now within thirty feet of the _NX-1._ It had crept up silently, without warning.

And, spanning the short gulf between them, an arm of webbed metal craned from the other's huge bow, hooking tightly into the American submarine's forward hawser holes!

As they took this in, the enemy ship moved away and the arm of metal tightened. The _NX-1_ shuddered. And, at first slowly, but with ever increasing speed, she got under way and slid after her captor. They were being towed away. Kidnaped! Men, submarine and all!

Keith Wells mopped sweat from a hot brow and rapidly reviewed his weapons. He was sorely restricted. Through an emergency system the _NX-1_ could be propelled and maneuvered from her control room; but the torpedo tubes needed local attendance.

"Hemmy, reverse engines," he jerked, himself spinning over a small wheel. "Let's see if we can out-pull the devil!"

At once they felt the shock of the paralyzing ray, and then the surging whine of the Edsel electrics pulsed up and in the teleview screen they watched the grim struggle of ship against ship.

Imperceptibly, almost, as her screws cut in and churned, the forward progress of the _NX-1_ was slowing, the speed of the other being cut down, until finally they but barely forged ahead. Slowly, ever so slowly they were out-pulled; inch by inch they were dragged ahead.

Their motors could not hold even.

"She's more powerful than we!" Wells' bitter voice spoke. "d.a.m.n!" He thought desperately, while Bowman and Brown stared at the fantastic tale the teleview spelled out.

Again the paralyzing shock tingled, an intangible jailer that bound them, more surely than steel bars, to the control room. To dare that streaming barrage meant instant impotence, and perhaps, later, death....

"Our two bow torpedoes," Keith mused slowly. "We're a bit close, but it's our only chance. The ray comes at intervals of about a minute; the torps are ready for firing. If one of us could dash forward and discharge 'em.... Brown, that's you!"

The petty officer met his commander's gaze levelly. He smiled. "Yes, sir, I'm ready!" he said.

"Good! It'll have to be quick work, though; I'll try and keep the sub pointed straight. Wait for the ray, then run like h.e.l.l!"

The first officer took over the helm and Brown stepped to the forward ladder, waiting for the periodic ray to be discharged.