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, guttural 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: