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 mess-room, 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 has 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 in 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 then 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 then, 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 tonight!” 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 him, 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.