The Sunken Empire

By H. Thompson Rich

Concerning the strange adventures of Professor Stevens with the Antillians on the floor of the mysterious Sargasso Sea.

"THEN you really expect to find the lost continent of Atlantis, Professor?"

Martin Stevens lifted his bearded face sternly to the reporter who was interviewing him in his study aboard the torpedo-submarine Nereid, a craft of his own invention, as she lay moored at her Brooklyn wharf, on an afternoon in October.

"My dear young man," he said, "I am not even going to look for it."

The aspiring journalist—Larry Hunter by name—was properly abashed.

"But I thought," he insisted nevertheless, "that you said you were going to explore the ocean floor under the Sargasso Sea?"

"And so I did," Professor Stevens admitted, a smile moving that gray beard now and his blue eyes twinkling merrily. "But the Sargasso, an area almost equal to Europe, covers other land as well— land of far more recent submergence than Atlantis, which foundered in 9564 B. C., according to Plato. What I am going to look for is this newer lost continent, or island rather —namely, the great island of Antillia, of which the West Indies remain above water to-day."

"Antillia?" queried Larry Hunter, wonderingly. "I never heard of it." Again the professor regarded his interviewer sternly.

"There are many things you have never heard of, young man," he told him. "Antillia may be termed the missing link between Atlantis and America. It was there that Atlantean culture survived after the appalling catastrophe that wiped out the Atlantean homeland, with its seventy million inhabitants, and it was in the colonies the Antillians established in Mexico and Peru, that their own culture in turn survived, after Antillia too had sunk."

"My Lord! You don't mean to say the Mayas and Incas originated on that island of Antillia?"

"No, I mean to say they originated on the continent of Atlantis, and that Antillia was the stepping stone to the New World, where they built the strange pyramids we find smothered in the jungle—even as thousands of years before the Atlanteans established colonies in Egypt and founded the earliest dynasties of pyramid-building Pharaohs."

LARRY was pushing his pencil furiously.

"Whew!" he gasped. "Some story, Professor!"

"To the general public, perhaps," was the reply. "But to scholars of antiquity, these postulates are pretty well known and pretty well accepted. It remains but to get concrete evidence, in order to prove them to the world at large—and that is the object of my expedition."

More hurried scribbling, then:

"But, say—why don't you go direct to Atlantis and get the real dope?"

"Because that continent foundered so long ago that it is doubtful if any evidence would have withstood the ravages of time," Professor Stevens explained, "whereas Antillia went down no earlier than 200 B. C., archaeologists agree."

"That answers my question," declared Larry, his admiration for this doughty graybeard rising momentarily. "And now, Professor, I wonder if you'd be willing to say a few words about this craft of yours?"

"Cheerfully, if you think it would interest anyone. What would you care to have me say?"

"Well, in the first place, what does the name Nereid mean?"

"Sea-nymph. The derivation is from the Latin and Greek, meaning daughter of the sea-god Nereus. Appropriate, don't you think?"

"Swell. And why do you call it a torpedo-submarine? How does it differ from the common or navy variety?"

PROFESSOR STEVENS smiled. It was like asking what was the difference between the sun and the moon, when about the only point of resemblance they had was that they were both round. Nevertheless, he enumerated some of the major modifications he had developed.

Among them, perhaps the most radical, was its motive power, which was produced by what he called a vacuo-turbine—a device that sucked in the water at the snout of the craft and expelled it at the tail, at the same time purifying a certain amount for drinking purposes and extracting sufficient oxygen to maintain a healthful atmosphere while running submerged.

Then, the structure of the Nereid was unique, he explained, permitting it to attain depths where the pressure would crush an ordinary submarine, while mechanical eyes on the television principle afforded a view in all directions, and locks enabling them to leave the craft at will and explore the sea-bottom were provided.

This latter feat they would accomplish in special suits, designed on the same pneumatic principle as the torpedo itself and capable of sustaining sufficient inflation to resist whatever pressures might be encountered, as well as being equipped with vibratory sending and receiving apparatus, for maintaining communication with those left aboard.

ALL these things and more Professor Stevens outlined, as Larry's pencil flew, admitting that he had spent the past ten years and the best part of his private fortune in developing his plans.

"But you'll get it all back, won't you? Aren't there all sorts of Spanish galleons and pirate barques laden with gold supposed to be down there?"

"Undoubtedly," was the calm reply. "But I am not on a treasure hunt, young man. If I find one single sign of former life, I shall be amply rewarded."

Whereupon the young reporter regarded the subject of his interview with fresh admiration, not unmingled with wonder. In his own hectic world, people had no such scorn of gold. Gee, he'd sure like to go along! The professor could have his old statues or whatever he was looking for. As for himself, he'd fill up his pockets with Spanish doubloons and pieces of eight!

Larry was snapped out of his trance by a light knock on the door, which opened to admit a radiant girl in creamy knickers and green cardigan.

"May I come in, daddy?" she inquired, hesitating, as she saw he was not alone.

"You seem to be in already, my dear," the professor told her, rising from his desk and stepping forward.

Then, turning to Larry, who had also risen, he said:

"Mr. Hunter, this is my daughter, Diane, who is also my secretary."

"I am pleased to meet you, Miss Stevens," said Larry, taking her hand.

And he meant it—for almost anyone would have been pleased to meet Diane, with her tawny gold hair, warm olive cheeks and eyes bluer even than her father's and just as twinkling, just as intelligent.

"She will accompany the expedition and take stenographic notes of everything we observe," added her father, to Larry's amazement.

"What?" he declared. "You mean to say that—that—"

"Of course he means to say that I'm going, if that's what you mean to say, Mr. Hunter," Diane assured him. "Can you think of any good reason why I shouldn't go, when girls are flying around the world and everything else?"

Even had Larry been able to think of any good reason, he wouldn't have mentioned it. But as a matter of fact, he had shifted quite abruptly to an entirely different line of thought. Diane, he was thinking—Diana, goddess of the chase, the huntress! And himself, Larry Hunter—the hunter and the huntress!

Gee, but he'd like to go! What an adventure, hunting around together on the bottom of the ocean!

WHAT a wild dream, rather, he concluded when his senses returned. For after all, he was only a reporter, fated to write about other people's adventures, not to participate in them. So he put away his pad and pencil and prepared to leave.

But at the door he paused.

"Oh, yes—one more question. When are you planning to leave, Professor?"

At that, Martin Stevens and his daughter exchanged a swift glance. Then, with a smile, Diane said:

"I see no reason why we shouldn't tell him, daddy."

"But we didn't tell the reporters from the other papers, my dear," protested her father.

"Then suppose we give Mr. Hunter the exclusive story," she said, transferring her smile to Larry now. "It will be what you call a—a scoop. Isn't that it?"

"That's it."

She caught her father's acquiescing nod. "Then here's your scoop, Mr. Hunter. We leave to-night."

To-night! This was indeed a scoop! If he hurried, he could catch the late afternoon editions with it.

"I—I certainly thank you, Miss Stevens!" he exclaimed. "That'll make the front page!"

As he grasped the door-knob, he added, turning to her father:

"And I want to thank you too, Professor—and wish you good luck!"

Then, with a hasty handshake, and a last smile of gratitude for Diane, he flung open the door and departed, unconscious that two young blue eyes followed his broad shoulders wistfully till they disappeared from view.

BUT Larry was unaware that he had made a favorable impression on Diane. He felt it was the reverse. As he headed toward the subway, that vivid blond goddess of the chase was uppermost in his thoughts.

Soon she'd be off in the Nereid, bound for the mysterious regions under the Sargasso Sea, while in a few moments he'd be in the subway, bound under the prosaic East River for New York.

No—damned if he would!

Suddenly, with a wild inspiration, the young reporter altered his course, dove into the nearest phone booth and got his city editor on the wire.

Scoop? This was just the first installment. He'd get a scoop that would fill a book!

And his city editor tacitly O. K.'d the idea.

With the result that when the Nereid drew away from her wharf that night, on the start of her unparalleled voyage, Larry Hunter was a stowaway.

THE place where he had succeeded in secreting himself was a small storeroom far aft, on one of the lower decks. There he huddled in the darkness, while the slow hours wore away, hearing only the low hum of the craft's vacuo-turbine and the flux of water running through her.

From the way she rolled and pitched, he judged she was still proceeding along on the surface.

Having eaten before he came aboard, he felt no hunger, but the close air and the dark quarters brought drowsiness. He slept.

When he awoke it was still dark, of course, but a glance at his luminous wrist-watch told him it was morning now. And the fact that the rolling and pitching had ceased made him believe they were now running submerged.

The urge for breakfast asserting itself, Larry drew a bar of chocolate from his pocket and munched on it. But this was scanty fare for a healthy young six-footer, accustomed to a liberal portion of ham and eggs. Furthermore, the lack of coffee made him realize that he was getting decidedly thirsty. The air, moreover, was getting pretty bad.

"All in all, this hole wasn't exactly intended for a bedroom!" he reflected with a wry smile.

Taking a chance, he opened the door a crack and sat there impatiently, while the interminable minutes ticked off.

The Nereid's turbine was humming now with a high, vibrant note that indicated they must be knocking off the knots at a lively clip. He wondered how far out they were, and how far down.

Lord, there'd be a riot when he showed up! He wanted to wait till they were far enough on their way so it would be too much trouble to turn around and put him ashore.

But by noon his powers of endurance were exhausted. Flinging open the door, he stepped out into the corridor, followed it to a companionway and mounted the ladder to the deck above.

There he was assailed by a familiar and welcome odor—food!

Trailing it to its origin, he came to a pair of swinging doors at the end of a cork-paved passage. Beyond, he saw on peering through, was the messroom, and there at the table, among a number of uniformed officers, sat Professor Stevens and Diane.

A last moment Larry stood there, looking in on them. Then, drawing a deep breath, he pushed wide the swinging doors and entered with a cheery:

"Good morning, folks! Hope I'm not too late for lunch!"

VARYING degrees of surprise greeted this dramatic appearance. The officers stared, Diane gasped, her father leaped to his feet with a cry.

"That reporter! Why—why, what are you doing here, young man?"

"Just representing the press."

Larry tried to make it sound nonchalant but he was finding it difficult to bear up under this barrage of disapproving eyes—particularly two very young, very blue ones.

"So that is the way you reward us for giving you an exclusive story, is it?" Professor Stevens' voice was scathing. "A representative of the press! A stowaway, rather—and as such you will be treated!"

He turned to one of his officers.

"Report to Captain Petersen that we have a stowaway aboard and order him to put about at once."

He turned to another.

"See that Mr. Hunter is taken- below and locked up. When we reach New York, he will be handed over to the police."

"But daddy!" protested Diane, as they rose to comply, her eyes softening now. "We shouldn't be too severe with Mr. Hunter. After all, he is probably doing only what his paper ordered him to."

GRATEFULLY Larry turned toward his defender. But he couldn't let that pass.

"No, I'm acting only on my own initiative," he said. "No one told me to come."

For he couldn't get his city editor involved, and after all it was his own idea.

"You see!" declared Professor Stevens. "He admits it is his own doing. It is clear he has exceeded his authority, therefore, and deserves no sympathy."

"But can't you let me stay, now that I'm here?" urged Larry. "I know something about boats. I'll serve as a member of the crew—anything."

"Impossible. We have a full complement. You would be more of a hindrance than a help. Besides, I do not care to have the possible results of this expedition blared before the public."

"I'll write nothing you do not approve."

"I have no time to edit your writings, young man. My own, will occupy me sufficiently. So it is useless. You are only wasting your breath—and mine."

He motioned for his officers to carry out his orders.

But before they could move to do so, in strode a lean, middle-aged Norwegian Larry sensed must be Captain Petersen himself, and on his weathered face was an expression of such gravity that it was obvious to everyone something serious had happened.

IGNORING Larry, after one brief look of inquiry that was answered by Professor Stevens, he reported swiftly what he had to say.

While cruising full speed at forty fathoms, with kite-aerial out, their wireless operator had received a radio warning to turn back. Answering on its call-length, he had demanded to know the sender and the reason for the message, but the information had been declined, the warning merely being repeated.

"Was it a land station or a ship at sea?" asked the professor.

"Evidently the latter," was the reply. "By our radio range-finder, we determined the position at approximately latitude 27, longitude 65."

"But that, Captain, is in the very area we are headed for."

"And that, Professor, makes it all the more singular."

"But—well, well! This is indeed peculiar! And I had been on the point of turning back with our impetuous young stowaway. What would you suggest, sir?"

Captain Petersen meditated, while Larry held his breath.

"To turn back," he said at length, in his clear, precise English, "would in my opinion be to give the laugh to someone whose sense of humor is already too well developed."

"Exactly!" agreed Professor Stevens, as Larry relaxed in relief. "Whoever this practical joker is, we will show him he is wasting his talents—even though it means carrying a supernumerary for the rest of the voyage."

"Well spoken!" said the captain. "But as far as that is concerned, I think I can keep Mr. Hunter occupied."

"Then take him, and welcome!"

Whereupon, still elated but now somewhat uneasy, Larry accompanied Captain Petersen from the mess-room; started to, that is. But at a glance of sympathy from Diane, he dared call out:

"Say—hold on, folks! I haven't had lunch yet!"

WHEN young Larry Hunter reported to the captain of the Nereid, after this necessary meal, he found that the craft had returned to the surface.

Assigned a pair of powerful binoculars, he was ordered to stand watch on the conning-tower and survey the horizon in every direction, in an effort to sight the vessel that had sent out that mysterious radio, but though he cast his good brown eyes diligently through those strong lenses, he saw not so much as a smoke tuft upon the broad, gray-blue surface of the hazy Atlantic.

Gradually, however, as the afternoon wore away, something else came in view. Masses of brownish seaweed, supported by small, berry-like bladders, began drifting by. Far apart at first, they began getting more and more dense, till at last, with a thrill, he realized that they were drawing into that strange area known as the Sargasso Sea.

Shortly after this realization dawned, he was ordered below, and as the tropic sun was sinking over that eery floating tombstone, which according to Professor Stevens marked a nation's grave, the Nereid submerged.

Down she slid, a hundred fathoms or more, on a long, even glide that took her deep under that veiling brown blanket.

IN the navigating room now, Larry stood with the captain, the professor and Diane, studying an illuminated panel on which appeared a cross of five squares, like a box opened out.

The central square reproduced the scene below, while those to left and right depicted it from port and starboard, and those to front and rear revealed the forward and aft aspects of the panorama, thus affording a clear view in every direction.

This, then, was the television device Professor Stevens had referred to the previous afternoon, its mechanical eyes enabling them to search every square inch of those mysterious depths, as they cruised along.

It was the central square that occupied their attention chiefly, however, as they stood studying the panel. While the others represented merely an unbroken vista of greenish water, this one showed the sea floor as clearly as though they had been peering down into a shallow lagoon through a glass-bottomed boat, though it must have been a quarter of a mile below their cruising level.

A wonderful and fearsome sight it was to Larry: like something seen in a nightmare—a fantastic desert waste of rocks and dunes, with here and there a yawning chasm whose ominous depths their ray failed to penetrate, and now and then a jutting plateau that would appear on the forward square and cause Captain Petersen to elevate their bow sharply.

But more thrilling than this was their first glimpse of a sunken ship—a Spanish galleon, beyond a doubt!

There she lay, grotesquely on her side, half rotted, half buried in the sand, but still discernible. And to Larry's wildly racing imagination, a flood of gold and jewels seemed to pour from her ruined coffers.

TURNING to Diane, he saw that her eyes too were flashing with intense excitement.

"Say!" he exclaimed. "Why don't we stop and look her over? There may be a fortune down there!"

Professor Stevens promptly vetoed the suggestion, however.

"I must remind you, young man," he said severely, "that this is not a treasure hunt."

Whereupon Larry subsided; outwardly, at least. But when presently the central square revealed another and then another sunken ship, it was all he could do to contain himself.

Now, suddenly, Diane cried out:

"Oh, daddy, look! There's a modern ship! A—a freighter, isn't it?"

"A collier, I would say," was her father's calm reply. "Rather a large one, too. Cyclops, possibly. She disappeared some years ago, en route from the Barbados to Norfolk. Or possibly it is any one of a dozen other steel vessels that have vanished from these seas in recent times. The area of the Sargasso, my dear, is known as 'The Port of Missing Ships.'"

"But couldn't we drop down and make sure which ship it is?" she pleaded, voicing the very thought Larry had been struggling to suppress. At the professor's reply, however, he was glad he had kept quiet.

"We could, of course," was his gentle though firm rebuke, "but if we stopped to solve the mystery of every sunken ship we shall probably see during this cruise, we would have time for nothing else. Nevertheless, my dear, you may take a short memorandum of the location and circumstances, in the present instance."

Whereupon he dictated briefly, while Larry devoted his attention once more to the central square.

SUDDENLY, beyond a dark pit that seemed to reach down into the very bowels of the earth, rose an abrupt plateau—and on one of its nearer elevations, almost directly under them, loomed a monumental four-sided mound.

"Say—hold on!" called Larry. "Look at that, Professor! Isn't that a building of some kind?"

Martin Stevens looked up, glanced skeptically toward the panel. But one glimpse at what that central square revealed, and his skepticism vanished.

"A building?" he cried in triumph. "A building indeed! It is a pyramid, young man!"

"Good Lord!"

"Oh, daddy! Really?"

"Beyond a doubt! And look—there are two other similar structures, only smaller!"

Struggling for calm, he turned to Captain Petersen, who had taken his eyes from the forward square and was peering down as well upon those singular mounds.

"Stop! Descend!" was his exultant command. "This is my proof! We have discovered Antillia!"

SWIFTLY the Nereid dropped to that submerged plateau.

In five minutes, her keel was resting evenly on the smooth sand beside the largest of the three pyramids.

Professor Stevens then announced that he would make a preliminary investigation of the site at once.

"For, otherwise, I for one would be quite unable to sleep to-night!" declared the graybeard, with a boyish chuckle.

He added that Diane would accompany him.

At this latter announcement, Larry's heart sank. He had hoped against hope that he might be invited along with them.

But once again his champion came to his aid.

"We really ought to let Mr. Hunter come with us, daddy, don't you think?" she urged, noting his disappointment. "After all, it was he who made the discovery."

"Very true," said her father, "but I had not thought it necessary for anyone to accompany us. In the event anyone does, Captain Petersen should have that honor."

But this honor the captain declined.

"If you don't mind, sir, I'd prefer to stay with the ship," he said, quietly. "I haven't forgotten that radio warning."

"But surely you don't think anyone can molest us down here?" scoffed the professor.

"No, but I'd prefer to stay with the ship just the same, sir, if you don't mind."

"Very well"—with a touch of pique. "Then you may come along if you care to, Mr. Hunter."

If he cared to!

"Thanks, Professor!" he said with a grateful look toward Diane. "I'd be keen to!"

SO he accompanied them below, where they donned their pressure-suits—rubber affairs rather less cumbersome than ordinary deep-sea diving gear, reinforced with steel wire and provided with thick glass goggles and powerful searchlights, in addition to their vibratory communication apparatus and other devices that were explained to Larry.

When he had mastered their operation, which was rendered simple by reason of the fact that they were so nearly automatic, the trio stepped into a lock on the floor of the ship and Professor Stevens ordered them to couple their suits to air-valve connections on the wall, at the same time admitting water by opening another valve.

Swiftly the lock flooded, while their suits inflated.

"All right?" came his vibratory query.

"Right!" they both answered.

"Then stand by for the heavy pressure."

Wider now he opened the water-valve, letting the ocean in, while at the same time their suits continued inflating through their air-valve connections.

To his surprise, Larry found himself no more inconvenienced by the pressure than he had been from the moment the submarine dove to its present depth. Indeed, most of the air that was coming into his suit was filling the reinforced space between its inner and outer layers, much as the Nereid held air under pressure between her two thick shells.

"All right now?" called out the professor's vibrator.

"Right!" they called back again.

"Then uncouple your air-valve connections and make ready."

They did so, and he likewise.

Then, advancing to a massive door like that of a vault, he flung back its powerful clamps, dragged it open—and there beyond, its pressure equaled by that within the lock, loomed the black tide of the ocean bottom.

AWED by this solemn sight, tingling with a sense of unparalleled adventure, Larry stood there a moment, peering out over the threshold of that untrodden world.

Then he followed Diane and her father into its beckoning mystery....

Their searchlights cutting bright segments into the dark, they proceeded toward the vast mound that towered ahead, pushing through a weird realm of phosphorescent fish and other marine creatures.

As they neared it, any possible doubt that it was in fact a pyramid vanished. Corroded by the action of salt water and covered with the incrustations of centuries, it nevertheless presented unmistakable evidence of human construction, rising in steps of massive masonry to a summit shadowy in the murk above.

As Larry stood gazing upon that mighty proof that this submerged plateau had once stood forth proudly above the sea, he realized that he was a party to one of the most profound discoveries of the ages. What a furore this would make when he reported it back to his New York paper!

But New York seemed remote indeed, now. Would they ever get back? What if anything went wrong with their pressure-suits—or if they should become lost?

He glanced back uneasily, but there gleamed the reassuring lights of the Nereid, not a quarter of a mile away.

Diane and her father were now rounding a corner of the pyramid and he followed them, his momentary twinge of anxiety gone.

FOR some moments, Professor Stevens prowled about without comment, examining the huge basal blocks of the structure and glancing up its sloping sides.

"You see, I was right!" he declared at length. "This is not only a man-made edifice but a true pyramid, embodying the same architectural principles as the Mayan and Egyptian forms. We see before us the visible evidence of a sunken empire—the missing link between Atlantis and America."

No comments greeted this profound announcement and the professor continued:

"This structure appears to be similar in dimensions with that of the pyramid of Xochicalco, in Mexico, which in turn approximates that of the 'Sacred Hill' of Atlantis, mentioned by Plato, and which was the prototype of both the Egyptian and Mayan forms. It was here the Antillians, as the Atlanteans had taught them to do, worshipped their grim gods and performed the human sacrifices they thought necessary to appease them. And it was here, too, if I am not mistaken, that—"

Suddenly his vibratory discourse was broken into by a sharp signal from the submarine:

"Pardon interruption! Hurry back! We are attacked!"

At this, the trio stood rigid.

"Captain Petersen! Captain Petersen!" Larry heard the professor call. "Speak up! Give details! What has happened?"

But an ominous silence greeted the query.

Another moment they stood there, thoroughly dismayed now. Then came the professor's swift command:

"Follow me—quickly!"

He was already in motion, retracing his steps as fast as his bulky suit would permit. But as he rounded the corner of the pyramid, they saw him pause, stand staring. And as they drew up, they in turn paused; stood staring, too.

With sinking hearts, they saw that the Nereid was gone.

STUNNED by this disaster, they stood facing one another—three lone human beings, on the bottom of the Atlantic ocean, their sole means of salvation gone.

Professor Stevens was the first to speak.

"This is unbelievable!" he said. "I cannot credit it. We must have lost our senses."

"Or our bearings!" added Diane, more hopefully. "Suppose we look around the other side."

As for Larry, a darker suspicion flashed through his mind. Captain Petersen! Had he seized his opportunity and led the crew to mutiny, in the hope of converting the expedition into a treasure hunt? Was that the reason he had been so willing to remain behind?

He kept his suspicion to himself, however, and accompanied Diane and her father on a complete circuit of the pyramid; but, as he feared, there was no sign of the Nereid anywhere. The craft had vanished as completely as though the ocean floor had opened and swallowed her up.

But no, not as completely as that! For presently the professor, who had proceeded to the site where they left the craft resting on the sand, called out excitedly:

"Here—come here! There are tracks! Captain Petersen was right! They were attacked!"

Hurrying to the scene, they saw before them the plain evidences of a struggle. The ocean bottom was scuffed and stamped, as though by many feet, and a clear trail showed where the craft had finally been dragged away.

Obviously there was but one thing to do and they did it. After a brief conference, they turned and followed the trail.

IT led off over the plateau a quarter mile or more, in an eastward direction, terminating at length beside one of the smaller pyramids—and there lay the Nereid, apparently unharmed.

But her lights were out and there came no answer to their repeated calls, so they judged she must be empty.

What had happened to Captain Petersen and his crew? What strange sub-sea enemy had overcome them? What was now their fate?

Unanswerable question! But one thing was certain. Larry had misjudged the captain in suspecting him of mutiny. He was sorry for this and resolved he would make amends by doing all in his power to rescue him and his men, if they were still living.

Meanwhile his own plight, and that of Diane and her father, was critical. What was to be done?

Suddenly, as all three stood there debating that question, Professor Stevens uttered an exclamation and strode toward the pyramid. Following him with their eyes, they saw him pass through an aperture where a huge block of stone had been displaced—and disappear within.

The next moment they had joined him, to find themselves in a small flooded chamber at whose far end a narrow gallery sloped upward at a sharp angle. The floor and walls were tiled, they noted, and showed none of the corrosion of the exterior surfaces. Indeed, so immaculate was the room that it might have been occupied but yesterday.

As they stood gazing around in wonder, scarcely daring to draw the natural inferences of this phenomena, there came a rasping sound, and, turning toward the entrance, they saw a massive section of masonry descend snugly into place.

They were trapped!

STANDING there tense, speechless, they waited, wondering what would be the next move of this strange enemy who held them now so surely in his power.

Nor had they long to wait.

Almost immediately, there issued a gurgling sound from the inclined gallery, and turning their eyes in the direction of this new phenomena, they saw that the water level was receding, as though under pressure from above.

"Singular!" muttered Professor Stevens. "A sort of primitive lock. It seems incredible that human creatures could exist down here, but such appears to be the case."

Larry had no desire to dispute the assumption, nor had Diane. They stood there as people might in the imminence of the supernatural, awaiting they knew not what.

Swiftly the water receded.

Now it was scarcely up to their waists, now plashing about their ankles, and now the room was empty.

The next moment, there sounded a rush of feet—and down the gallery came a swarm of the strangest beings any of them had ever seen.

They were short, thin, almost emaciated, with pale, pinched faces and pasty, half-naked bodies. But they shimmered with ornaments of gold and jade, like some strange princes from the realm of Neptune—or rather, like Aztec chieftains of the days of Cortes, thought Larry.

Blinking in the glare of the searchlights, they clamored around their captives, touching their pressure-suits half in awe and chattering among themselves.

THEN one of them, larger and more regally clad than the rest, stepped up and gestured toward the balcony.

"They obviously desire us to accompany them above," said the professor, "and quite as obviously we have little choice in the matter, so I suggest we do so."

"Check!" said Larry.

"And double-check!" added Diane.

So they started up, preceded by a handful of their captors and followed by the main party.

The gallery seemed to be leading toward the center of the pyramid, but after a hundred feet or so it turned and continued up at a right angle, turning twice more before they arrived at length in another stone chamber, smaller than the one below.

Here their guides paused and waited for the main party.

There followed another conference, whereupon their leader stepped up again, indicating this time that they were to remove their suits.

At this, Professor Stevens balked.

"It is suicide!" he declared. "The air to which they are accustomed here is doubtless at many times our own atmospheric pressure."

"But I don't see that there's anything to do about it," said Larry, as their captors danced about them menacingly. "I for one will take a chance!"

And before they could stop them, he had pressed the release-valve, emitting the air from his suit—slowly, at first, then more and more rapidly, as no ill effects seemed to result.

Finally, flinging off the now deflated suit, he stepped before them in his ordinary clothes, calling with a smile:

"Come on out, folks—the air's fine!"

THIS statement was somewhat of an exaggeration, as the air smelt dank and bad. But at least it was breathable, as Diane and her father found when they emerged from their own suits.

They discovered, furthermore, now that their flashlights were no longer operating, that a faint illumination lit the room, issuing from a number of small crystal jars suspended from the walls: some sort of phosphorescence, evidently.

Once again the leader of the curious throng stepped up to them, beaming now and addressing Professor Stevens in some barbaric tongue, and, to their amazement, he replied in words approximating its harsh syllables.

"Why, daddy!" gasped Diane. "How can you talk to him?"

"Simply enough," was the reply. "They speak a language which seems to be about one-third Basque, mixed oddly with Greek. It merely proves another hypothesis of mine, namely, that the Atlantean influence reached eastward to the Pyrenees mountains and the Hellenic peninsula, as well as to Egypt."

WHEREUPON he turned and continued his conversation, haltingly it is true and with many gestures, but understandably nevertheless.

"I have received considerable enlightenment as to the mystery of this strange sunken empire," he reported, turning back to them at length. "It is a singular story this creature tells, of how his country sank slowly beneath the waves, during the course of centuries, and of how his ancestors adapted themselves by degrees to the present conditions. I shall report it to you both, in detail, when time affords. But the main thing now is that a man similar to ourselves has conquered their country and set himself up as emperor. It is to him we are about to be taken."

"But it doesn't seem possible!" exclaimed Diane. "Why, how could he have got down here?"

"In a craft similar to our own, according to this creature. Heaven knows what it is we are about to face! But whatever it is, we will face it bravely."

"Check and double-check!" said Larry, with a glance toward Diane that told her she would not find him wanting.

They were not destined to meet the test just then, however, for just at that moment a courier in breech-clout and sandals dashed up the gallery and burst into the room, bearing in his right hand a thin square of metal.

Bowing, he handed it to the leader of the pigmy throng, with the awed word:

"Cabiri!"

At this, Professor Stevens gave a start.

"A message from their high priests!" he whispered.

Whatever it contained, the effect produced on the reader was profound. Facing his companions, he addressed them gravely. Then, turning from the room, he commanded the captives to follow.

THE way led back down the inclined gallery to a point where another door now stood open, then on down until finally the passage leveled out into a long, straight tunnel.

This they traversed for fully a mile, entering at length a large, square chamber where for a moment they paused. "I judge we are now at the base of the large pyramid," the professor voiced in an undertone. "It would naturally be the abode of the high priests."

"But what do you suppose they want with us?" asked Diane.

"That I am not disposed to conjecture," was her father's reply.

But the note of anxiety in his voice was not lost on Diane, nor on Larry, who pressed her hand reassuringly.

Now their captors led them from the room through a small door opening on another inclined gallery, whose turns they followed until all were out of breath from the climb.

It ended abruptly on a short, level corridor with apertures to left and right.

Into the latter they were led, finding themselves in a grotesquely furnished room, lit dimly by phosphorescent lamps.

Swiftly the leader addressed Professor Stevens. Then all withdrew. The aperture was closed by a sliding block of stone.

FOR a moment they stood there silent, straining their eyes in the gloom to detect the details of their surroundings, which included several curious chairs and a number of mattings strewn on the tiled floor.

"What did he say?" asked Diane at length, in a tremulous voice.

"He said we will remain here for the night," her father replied, "and will be taken before the high priests at dawn."

"At dawn!" exclaimed Larry. "How the deuce do they know when it is dawn, down here?"

"By their calendars, which they have kept accurately," was the answer. "But there are many other questions you must both want to ask, so I shall anticipate them by telling you now what I have been able to learn. Suppose we first sit down, however. I for one am weary."

Whereupon they drew up three of those curious chairs of some heavy wood carved with the hideous figures of this strange people's ancient gods, and Professor Stevens began.

THEIR sunken empire, as he had surmised, had indeed been the great island of Antillia and a colony of Atlantis. A series of earthquakes and tidal waves such as engulfed their homeland ages before had sent it down, and the estimated archaeological date of the final submergence—namely, 200 B. C.—was approximately correct.

But long before this ultimate catastrophe, the bulk of the disheartened population had migrated to Central and South America, founding the Mayan and Incan dynasties. Many of the faithful had stayed on, however, among them most of the Cabiri or high priests, who either were loath to leave their temples or had been ordered by their gods to remain.

At any rate, they had remained, and as the great island sank lower and lower, they had fortified themselves against the disaster in their pyramids, which by then alone remained above the Surface.

These, too, had gradually disappeared beneath the angry waters, however, and with them had disappeared the steadfast priests and their faithful followers, sealing their living tombs into air-tight bell-jars that retained the atmosphere.

This they had supplemented at first by drawing it down from above, but as time went by they found other means of getting air; extracting it from the sea water under pressure, by utilizing their subterranean volcanoes, in whose seething cauldrons the gods had placed their salvation; and it was this process that now provided them with the atmosphere which had so amazed their captives.

But naturally, lack of sunshine had produced serious degeneration in their race, and that accounted for their diminutive forms and pale bodies. Still, they had been able to survive with a degree of happiness until some ten or a dozen years ago, when a strange enemy had come down in a great metal fish, like that of these new strangers, and with a handful of men had conquered their country.

This marauder was after their gold and had looted their temples ruthlessly, carrying away its treasures, for which they hated him with a fury that only violation of their most sacred deities could arouse. Long ago they would have destroyed him, but for the fact that he possessed terrible weapons which were impossible to combat. But they were in smouldering rebellion and waited only the support of their gods, when they would fall on this oppressor and hurl him off.

That, though it left many things unexplained, was all the professor had been able to gather from his conversation with the leader of their captors. He ended, admitting regretfully that he was still in ignorance of what fate had befallen Captain Petersen and the crew of the Nereid.

"PERHAPS this fellow in the other submarine has got them," suggested Larry.

"But why weren't we taken to him, too?" asked Diane. "What do you suppose they want with us, anyway, daddy?"

"That, my dear, as I told you before," replied her father, "I am not disposed to conjecture. Time will reveal it. Meanwhile, we can only wait."

As before, there was a note of anxiety in his voice not lost on either of them. And as for Larry, though he knew but little of those old religions, he knew enough to realize that their altars often ran with the blood of their captives, and he shuddered.

With these grim thoughts between them, the trio fell silent.

A silence that was interrupted presently by the arrival of a native bearing a tray heaped with strange food.

Bowing, he placed it before them and departed.

Upon examination, the meal proved to consist mainly of some curious kind of steamed fish, not unpalatable but rather rank and tough. There were several varieties of fungus, too, more or less resembling mushrooms and doubtless grown in some sunless garden of the pyramid.

These articles, together with a pitcher of good water that had obviously been distilled from the sea, comprised their meal, and though it was far from appetizing, they ate it.

But none of the three slept that night, though Diane dozed off for a few minutes once or twice, for their apprehension of what the dawn might hold made it impossible, to say nothing of the closeness of the air in that windowless subterranean room.

Slowly, wearily, the hours dragged by.

At length the native who had brought their food came again. This time he spoke.

"He says we are now to be taken before the high priests," Professor Stevens translated for them.

Almost with relief, though their faces were grave, they stepped out into the corridor, where an escort waited.

FIVE minutes later, after proceeding along an inclined gallery that wound ever upward, they were ushered into a vast vaulted chamber lit with a thousand phosphorescent lamps and gleaming with idols of gold and silver, jewels flashing from their eyes.

High in the dome hung a great golden disc, representing the sun. At the far end, above a marble altar, coiled a dragon with tusks of ivory and scales of jade, its eyes two lustrous pearls.

And all about the room thronged priests in fantastic head-dress and long white robes, woven through elaborately with threads of yellow and green. At the appearance of the captives, a murmur like a chant rose in the still air. Someone touched a brand to the altar and there was a flash of flame, followed by a thin column of smoke that spiraled slowly upward.

Now one of the priests stepped out—the supreme one among them, to judge from the magnificence of his robe—and addressed the trio, speaking slowly, rhythmically.

As his strange, sonorous discourse continued, Professor Stevens grew visibly perturbed. His beard twitched and he shifted uneasily on his feet.

FINALLY the discourse ceased and the professor replied to it, briefly. Then he turned grave eyes on Larry and Diane.

"What is it?" asked the latter, nervously. "What did the priest say, daddy?"

Her father considered, before replying.

"Naturally, I did not gather everything," was his slow reply, "but I gathered sufficient to understand what is afoot. First, however, let me explain that the dragon you see over there represents their deity Tlaloc, god of the sea. In more happy circumstances, it would be interesting to note that the name is identified with the Mayan god of the same element."

He paused, as though loath to go on, then continued:

"At any rate, the Antillians have worshipped Tlaloc principally, since their sun god failed them. They believe he dragged down their empire in his mighty coils, through anger with them, and will raise it up again if appeased. Therefore they propose today to—"

"Daddy!" cried Diane, shrinking back in horror, while a chill went up Larry's spine. "You mean—mean that—"

"I mean, my poor child, that we are about to be sacrificed to the dragon god of the Antillians."

THE words were no more than uttered, when with a weird chant the Cabiri closed in on their victims and led them with solemn ceremonial toward the altar.

In vain did Professor Stevens protest. Their decision had been made and was irrevocable. Tlaloc must be appeased. Lo, even now he roared for the offering!

They pointed to the dragon, from whose nostrils suddenly issued hissing spurts of flame.

Larry fumed in disgust at the cheap hocus-pocus of it—but the next moment a more violent emotion swept over him as he saw Diane seized and borne swiftly to that loathesome shrine.

But even as he lunged forward, the professor reached his daughter's side. Throwing himself in front of her, he begged them to spare her, to sacrifice him instead.

The answer of the priests was a blow that knocked the graybeard senseless, and lifting Diane up, half-swooning, they flung her upon the altar.

"Mr. Hunter! Larry!" came her despairing cry.

She struggled up and for a moment her blue eyes opened, met his beseechingly.

That was enough—that and that despairing cry, "Larry!"

With the strength of frenzy, he flung off his captors, rushed to her aid, his hard fists flailing.

The pigmies went down in his path like grain before the scythe. Reaching the altar, he seized the priest whose knife was already upraised, and, lifting him bodily, flung him full into the ugly snout of that snorting dragon.

Then, as a wail of dismay rose from the Cabiri, at this supreme sacrilege, he seized the now unconscious Diane and retreated with her toward the door.

BUT there spears barred his escape; and now, recovered from the first shock of this fearful affront to their god, the priests started toward him.

Standing at bay, with that limp, tender burden in his arms, Larry awaited the end.

As the maddened horde drew near, she stirred, lifted her pale face and smiled, her eyes still shut.

"Oh, Larry!"

"Diane!"

"You saved me. I won't forget."

Then, the smile still lingering, she slipped once more into merciful oblivion, and as Larry held her close to his heart, a new warmth kindled there.

But bitterness burned in his heart, too. He had saved her—won her love, perhaps—only to lose her. It wasn't fair! Was there no way out?

The priests were close now, their pasty faces leering with fierce anticipation of their revenge, when suddenly, from down the gallery outside that guarded door, came the sharp crash of an explosion, followed by shouts and the rush of feet.

At the sound, the priests trembled, fled backward into the room and fell moaning before their idols, while the quaking guards strove frantically to close the door.

BUT before they could do so, in burst a half dozen brawny sailors in foreign uniform, bearing in their hands little black bulbs that looked suspiciously like grenades. Shouting in a tongue Larry could not distinguish above the uproar, they advanced upon the retreating guards and priests.

Then, when all were herded in the far corner of the room, the sailors backed toward the door. Motioning for Larry and Diane to clear out, they raised those sinister little missiles, prepared to fling them.

"Wait!" cried Larry, thinking of Professor Stevens.

And releasing Diane, who had revived, he rushed forward, seized the prostrate savant from amid the unresisting Cabiri, and bore him to safety.

"Daddy!" sobbed Diane, swaying to meet them.

"Back!" shouted one of the sailors, shoving them through the door.

The last glimpse Larry had of that fateful room was the horde of priests and guards huddled before their altar, voices lifted in supplication to that hideous dragon god.

Then issued a series of blinding flashes, followed by deafening explosions, mingled with shrieks of anguish.

Sickened, he stood there, as the reverberations died away.

PRESENTLY, when it was plain no further menace would come from that blasted temple, their rescuers led the trio back down those winding galleries and through that long, straight tunnel to the smaller pyramid.

Professor Stevens had recovered consciousness by now and was able to walk, with Larry's aid, though a matted clot of blood above his left ear showed the force of the blow he had received.

The way, after reaching the smaller pyramid, led up those other galleries they had mounted the night before.

This time, undoubtedly, they were to be taken before that mysterious usurping emperor. And what would be the result of that audience? Would it but plunge them from the frying pan into the fire, wondered Larry, or would it mean their salvation?

Anyway, he concluded, no fate could be worse than the hideous one they had just escaped. But if only Diane could be spared further anguish!

He glanced at her fondly, as they walked along, and she returned him a warm smile.

Now the way led into a short, level passage ending in a door guarded by two sailors with rifles. They presented arms, as their comrades came up, and flung open the door.

As he stepped inside, Larry blinked in amazement, for he was greeted by electric lights in ornate clusters, richly carpeted floors, walls hung with modern paintings—and there at the far end, beside a massive desk, stood an imposing personage in foreign naval uniform of high rank, strangely familiar, strangely reminiscent of war days.

Even before the man spoke, in his guttural English, the suspicion those sailors had aroused crystallized itself.

A German! A U-boat commander!

"GREETINGS, gentlemen—and the little lady," boomed their host, with heavy affability. "I see that my men were in time. These swine of Antillians are a tricky lot. I must apologize for them—my subjects."

The last word was pronounced with scathing contempt.

"We return greetings!" said Professor Stevens. "To whom, might I ask, do we owe our lives, and the honor of this interview?"

Larry smiled. The old graybeard was up to his form, all right!

"You are addressing Herr Rolf von Ullrich," the flattered German replied, adding genially: "commander of one of His Imperial Majesty's super-submarines during the late war and at present Emperor of Antillia."

To which the professor replied with dignity that he was greatly honored to make the acquaintance of so exalted a personage, and proceeded in turn to introduce himself and party. But Von Ullrich checked him with a smile.

"The distinguished Professor Stevens and his charming daughter need no introduction, as they are already familiar to me through the American press and radio," he said. "While as for Mr. Hunter, your Captain Petersen has already made me acquainted with his name."

At the mention of the commander of the Nereid, all three of them gave a start.

"Then—then my captain and crew are safe?" asked the professor, eagerly.

"Quite," Von Ullrich assured him. "You will be taken to them presently. But first there are one or two little things you would like explained—yes? Then I shall put to you a proposal, which if acceptable will guarantee your safe departure from my adopted country."

Whereupon the German traced briefly the events leading up to the present.

DURING the last months of the war, he had been placed in command of a special U-boat known as the "mystery ship"—designed to resist depth-charges and embodying many other innovations, most of them growing out of his own experience with earlier submarines.

One day, while cruising off the West Indies, in wait for some luckless sugar boat, he had been surprised by a destroyer and forced to submerge so suddenly that his diving gear had jammed and they had gone to the bottom. But the craft had managed to withstand the pressure and they had been able to repair the damage, limping home with a bad leak but otherwise none the worse for the experience.

The leak repaired and the hull further strengthened, he had set out again. But when in mid-Atlantic the Armistice had come, and rather than return to a defeated country, subject possibly to Allied revenge, he had persuaded his crew to remain out and let their craft be reported missing.

What followed then, though Von Ullrich masked it in polite words, was a story of piracy, until they found by degrees that there was more gold on the bottom of the ocean than the top; and from this to the discovery of the sunken empire where he now held reign was but a step.

They had thought at first they were looting only empty temples—but, finding people there, had easily conquered them, though ruling them, he admitted, was another matter. As, for instance, yesterday, when the priests had interfered with his orders and carried his three chief captives off to sacrifice.

"Where now, but for me, you would be food for their gods!" he ended. "And if you do not find any hospitality altogether to your liking, friends, remember that you came uninvited. In fact, if you will recall, you came despite my explicit warning!"

BUT since they were here, he told them, they might be willing to repay his good turn with another.

Whereupon Von Ullrich launched into his proposal, which was that Professor Stevens place the Nereid at his disposal for visiting the depths at the foot of the plateau, where lay the capital of the empire, he said—a magnificent metropolis known as the City of the Sun and modeled after the great Atlantean capital, the City of the Golden Gates, and the depository of a treasure, the greedy German believed, that was the ransom of the world.

The professor frowned, and for a moment Larry thought he was going to remind their host that this was not a treasure hunt.

"Why," he asked instead, "do you not use your own submarine for the purpose?"

"Because for one thing, she will not stand the pressure, nor will our suits," was the reply. "And for another, she is already laden with treasure, ready for an—er—forced abdication!" with a sardonic laugh.

"Then have you not enough gold already?"

"For myself, yes. But there are my men, you see—and men who have glimpsed the treasures of the earth are not easily satisfied, Professor. But have no fear. You shall accompany us, and, by your aid, shall pay your own ransom."

VON ULLRICH made no mention of the alternative, in case the aid was refused, but the ominous light Larry caught in his cold gray eyes spoke as clearly as words.

So, since there was nothing else to do, Professor Stevens agreed.

Whereupon the audience terminated and they were led from the presence of this arrogant German to another apartment, where they were to meet Captain Petersen and the crew of the Nereid.

As they proceeded toward it, under guard, Larry wondered why Von Ullrich had even troubled to make the request, when he held it in his power to take the craft anyway.

But after the first joyful moment of reunion, it was a mystery no longer, for Captain Petersen reported that immediately upon their capture, the commander of the U-boat had tried to force him to reveal the operation of the Nereid, but that he had steadfastly refused, even though threatened with torture.

And to think, it came to Larry with a new twinge of shame, that he had suspected this gallant man of mutiny!

THAT very morning, while Professor Stevens and his party were still exchanging experiences with Captain Petersen and the members of the crew, Von Ullrich sent for them and they gathered with his own men in the small lock-chamber at the base of the pyramid.

There they were provided with temporary suits by their host, since their own—which they brought along—could be inflated only from the Nereid.

Beside her, they noted as they emerged in relays, the U-boat was now moored.

Entering their own craft, they got under way at once and headed swiftly westward toward the brink of the plateau. Most of Von Ullrich's crew were with them, though a few had been left behind to guard against any treachery on the part of the now sullen and aroused populace.

Slipping out over the edge of that precipitous tableland, they tilted her rudders and dove to the abysm below. Presently the central square of the illuminated panel in the navigating room showed three great concentric circles, enclosed by a quadrangle that must have been miles on a side—and within this vast sunken fortress lay a city of innumerable pyramids and temples and palaces.

The German's eyes flashed greedily as he peered upon this vision.

"There you are!" he exclaimed, quivering with excitement. "Those circles, that square: what would you judge they were, Professor?"

"I would judge that originally they were the canals bearing the municipal water supply," Martin Stevens told him quietly, suppressing his own excitement, "for such was said to be the construction of the City of the Golden Gates; but now I judge they are walls raised on those original foundations by the frantic populace, when the submergence first began, in a vain effort to hold back the tides that engulfed them."

"And do you think they are of gold?"

"Frankly, no; though I have no doubt you will find plenty of that element down there."

Nor was the prediction wrong, for modern eyes had never seen such a treasure house as they beheld when presently the Nereid came to rest outside that ancient four-walled city and they forced their way inside.

THOUGH the walls were not of gold, the inner gates were, and the temples were fairly bursting with the precious metal, as well as rare jewels, the eyes of a thousand idols gleaming with rubies and emeralds.

But where was the populace, amid all this prodigious wealth? Was there no life down here?

Von Ullrich declared through the vibrator of his pressure-suit that he had heard there was. And as though in substantiation, many of the temples showed the same bell-jar construction as the pyramids above, though even stouter, revealing evidences of having been occupied very recently; but all were flooded and empty. The city was as a city of the dead.

This ominous sign did not deter the "emperor," however. Ruthlessly he and his men looted those flooded temples, forcing Professor Stevens and his party to lend aid in the orgy of pillage.

And all the time, Larry had an uneasy feeling of gathering, furtive hosts about them, waiting—waiting for what?

He confided his fears to no one, though he noted with relief that Von Ullrich seemed to sense these unseen presences too, for he proceeded with caution and always kept a strong guard outside.

BY early afternoon, the Nereid was one great coffer-chest.

But still the rapacious U-boat commander was unsatisfied, though Professor Stevens began to have doubts if his craft could lift that massive weight of plunder to the top of the plateau.

"One more load and we go," he soothed. "A few more pretties for the little lady!"

Larry writhed, and should have suspected then and there—but as it was, the blow fell unexpected, stunning.

Filing from the lock, they failed to notice that Von Ullrich and his crew hung back, until there came a sudden, gutteral command, whereupon Diane was seized and the massive door flung shut in their faces.

Appalled by this overwhelming disaster, the party stood for a moment motionless, speechless. Then, as one, Larry and the professor rushed forward and beat upon that barred hatch, calling upon Von Ullrich to open it.

From within the submarine, through their vibrators, they heard him laugh.

"Auf wiedersehen!" he toasted them "I now have all the treasure I want! The rest I leave to you! Help yourselves!"

Even as he spoke, the Nereid's auxiliary propellers started churning the water. Slowly, sluggishly, like some great gorged fish, the sturdy craft moved off, lifted her snout, headed upward.

PROFESSOR STEVENS bowed his head, and Larry could well picture the grief that distorted the graybeard's face, inside that owl-eyed helmet.

"Cheer up!" he said, though his own face was twisted with anguish. "Perhaps—"

Then he paused—for how could he say that perhaps the situation wasn't as bad as it seemed, when it was obviously hopeless?

"My poor Diane!" moaned the professor. "Poor child. Poor child!"

As for Captain Petersen and the crew, they said nothing. Perhaps they were thinking of Diane, perhaps of themselves. At least, they knew it was over.

Or so they thought. But to Larry, suddenly, occurred a gleam of hope. That strange sense of unseen presences! It was bizarre, of course, but doesn't a drowning person catch at straws? And Lord knows they were drowning, if ever anyone was!

He turned and confided to Professor Stevens his idea, which was to retrace their steps within the city gates, seek out the populace and throw themselves on their mercy.

The stricken savant, too, grasped at the straw.

"It seems fantastic, but after all it is a chance," he admitted.

So they pushed back into that great submerged city, with Captain Petersen and his skeptical crew. They entered one of the largest of the temples, wandered forlornly through its flooded halls and corridors, seeking some sign of these alleged beings Larry had sensed.

Nor was their search unrewarded, for suddenly the captain himself, most skeptical of all, cried out:

"Listen! Did you hear that?"

There was no need to ask the question, for all had heard. It was a rasping sound, as of some great door swinging shut, followed almost immediately by a rushing gurgle—and as they stood there tense, the water level began rapidly receding.

Even while it was still plashing about their ankles, a secret block of masonry slid back and a horde of Antillians burst in upon them.

WHAT happened then, happened with a rush that left them dazed.

Unable to talk directly with the pigmies, by reason of their pressure-suits, which they dared not remove, they started gesturing with them, trying to explain their predicament and make known that they bore them no ill-will, but the creatures waved for them to cease and led them swiftly through the now waterless temple.

"Well, I guess it's all up!" said Larry, adding with dismal humor:

"They're probably going to finish that meal they started feeding their dragon last night!"

No one laughed, nor made any comment, and he relapsed into silence, realizing that they probably held him responsible for this latest disaster.

Leaving the temple, their captors led them into a passage that was level for a time, then inclined sharply. It was laborious going but they struggled on.

"I believe they know we are not their enemies!" declared Professor Stevens, at length, to everyone's cheer. "They seem to be leading us back to the plateau by some underground passage."

"Let's hope so!" said Larry. "Perhaps I had the right hunch after all."

"But my poor Diane!" came the professor's sorrowing after-thought. "That fiend Von Ullrich could never get the Nereid up safely."

"I think perhaps he could, with Miss Stevens to help him," put in Captain Petersen, his usual optimism returning. "She is thoroughly familiar with the craft's operation."

"That is so," her father admitted, his tone brighter. "But—"

"Of course it's so!" exclaimed Larry, breaking off any less hopeful reflections. "So cheerio, folks, as the English say. We'll make it yet!"

But in his heart, he was tormented with doubt for Diane's safety....

THE trail was growing eery, now, and precipitous. To their right rose a sheer cliff. To their left, the path fell off abruptly to a gigantic caldron where red flames leaped and waned.

"Looks like something out of Dante's 'Inferno!'" muttered Larry, with a shudder.

"The volcano where they distill their atmosphere, evidently," commented Professor Stevens. "It would have been interesting, in other circumstances, to observe the process."

"Not to me, it wouldn't!"

Larry was glad when they had passed that seething hell-pot and were once more proceeding through a long, dark gallery.

But everywhere, though their guides were but a handful, was a sense of those unseen presences, of gathering, furtive hosts about them, waiting—waiting for what?

What was this strange sense of tension, of foreboding, that hung in the air? Was the professor wrong? Were they being led to their doom, after all?

He was soon to know, for now the gallery they had been traversing levelled out into a series of short passages, each barred by a heavy stone door, and finally they were led into a small, square room, barely large enough to admit them all.

There, with gestures toward the far end, their guides left them.

The door closed, and almost immediately another on the opposite side opened, slowly at first, then wider and wider, admitting a rush of water that promptly filled the room.

Stepping wonderingly out, they found themselves on the upper level, beside the second of the two smaller pyramids.

"WHEW!" gasped Larry, as they stood looking around, still a little dazed. "These people are sure quick-change artists! First they try to feed you to their gods, then they save you from almost as bad a fate. Dizzy, I call it!"

"Quite understandable, I should say," declared the' professor. "Unable to cope with Von Ullrich themselves, they think perhaps we may be able to."

"Well, let's hope they're right!" grimly. "If once I get my hands on him—"

He broke off suddenly, as Captain Petersen called out:

"The Nereid! There she is!"

Following with their eyes the bright segment cut into the murky depths by his flashlight, they saw the familiar outlines of their craft; and close beside her lay the U-boat.

A feverish activity seemed to be going on between the two submarines.

"They're changing cargo!" cried Larry. "Quick! We've got them now!"

But the progress they were able to make, hampered by their heavy suits, was maddeningly slow. Their searchlights, moreover, betrayed their approach. Before they could reach the scene, most of the sailors had abandoned their task and piled into the U-boat.

Arms swinging wildly, Von Ullrich stood beside it, trying to rally them. Refusing to risk combat, however, since they were unable to use their deadly hand-grenades under water, they continued clambering up the sides of their submersible and shoving down through its conning-tower hatch.

Now a figure in a familiar pressure-suit broke away and started toward the advancing party.

It was Diane!

EVEN as he recognized her, Larry saw Von Ullrich lunge forward, seize his captive and mount to the conning-tower with her—but before the German could thrust her into the hatch, he had reached the U-boat's side and clambered to her rescue.

Dropping Diane, Von Ullrich wheeled to face his assailant. They grappled, fell to the deck, rolled over and over.

But suddenly, as they were struggling, there came a sound that caused the German to burst free and leap to his feet.

It was the sound of engines under them!

Ignoring Larry now, Von Ullrich staggered to the conning-tower hatch. It was battened fast. Frantically he beat on it.

This much Larry saw, as he knelt there getting his breath. Then he rose, took Diane by the arm and led her down. And he was none too soon, for with a lunge the U-boat got under way. But she seemed unable to lift her loot-laden mass from the ocean floor, and headed off crazily across the plateau, dragging her keel in the sand.

With fascinated horror, they watched the craft's erratic course, as it swung loggily westward and headed toward that yawning abysm from which they had all so lately risen.

The last sight they had of the U-boat was as it reached the brink, its despairing commander still standing in the conning-tower, hammering vainly on that fast-bound hatch; then they turned away faint, as the doomed craft plunged down, stern up, into those crushing depths.

PROFESSOR STEVENS now joined them.

"A lesson in avarice," he said gravely, when he had greeted his daughter with heartfelt relief. "And a typical fate of fortune hunters! Let that be a lesson to you, young man."

"Amen!" said Larry.

"But what happened, my dear?" asked the professor of Diane, a moment later. "Why were they in such a hurry to be off?"

"Because the sensible Antillians seized their opportunity and overcame what they had been waiting for! They had been waiting for that usurping vandal to depart.

And how they must be gloating now, down there!

"But why were they so eager to abandon the Nereid?" asked the savant, still puzzled. "It is a better boat than theirs, even if I do say so myself."

"Because I put it out of commission, directly we got back up here," replied Diane. "But not permanently!" she added, with what Larry knew was a smile, though he couldn't see her face, of course, through the helmet of her pressure-suit.

"Little thoroughbred!" he exclaimed, half to himself.

"What did you say, Mr. Hunter?— Larry, I mean," she inquired.

"N-nothing," he replied uneasily.

"Fibber!" said Diane. "I heard you the first time!"

"Just wait till I get out of this darned suit!" said Larry.

"I guess I can wait that long!" she told him.

And if Professor Stevens heard any of this, it went in one ear and out the other, for he was thinking what a report he would have to make to his confrères when they got home—particularly with half a boatload of idols for proof.