The noise of their own paddles drowned the sound of mine, but in another instant the growing light ahead would reveal me to them.

There was no time to be lost. Whatever action I was to take must be taken at once. Swinging the prow of my boat toward the right, I sought the river's rocky side, and there I lay while Matai Shang and Thurid approached up the center of the stream, which was much narrower than the Iss.

As they came nearer I heard the voices of Thurid and the Father of Therns raised in argument.

"I tell you, Thern," the black dator was saying, "that I wish only vengeance upon John Carter, Prince of Helium. I am leading you into no trap. What could I gain by betraying you to those who have ruined my nation and my house?"

"Let us stop here a moment that I may hear your plans," replied the hekkador, "and then we may proceed with a better understanding of our duties and obligations."

To the rowers he issued the command that brought their boat in toward the bank not a dozen paces beyond the spot where I lay.

Had they pulled in below me they must surely have seen me against the faint glow of light ahead, but from where they finally came to rest I was as secure from detection as though miles separated us.

The few words I had already overheard whetted my curiosity, and I was anxious to learn what manner of vengeance Thurid was planning against me. Nor had I long to wait. I listened intently.

"There are no obligations, Father of Therns," continued the First Born. "Thurid, Dator of Issus, has no price. When the thing has been accomplished I shall be glad if you will see to it that I am well received, as is befitting my ancient lineage and noble rank, at some court that is yet loyal to thy ancient faith, for I cannot return to the Valley Dor or elsewhere within the power of the Prince of Helium; but even that I do not demand—it shall be as your own desire in the matter directs."

"It shall be as you wish, Dator," replied Matai Shang; "nor is that all—power and riches shall be yours if you restore my daughter, Phaidor, to me, and place within my power Dejah Thoris, Princess of Helium.

"Ah," he continued with a malicious snarl, "but the Earth man shall suffer for the indignities he has put upon the holy of holies, nor shall any vileness be too vile to inflict upon his princess. Would that it were in my power to force him to witness the humiliation and degradation of the red woman."

"You shall have your way with her before another day has passed, Matai Shang," said Thurid, "if you but say the word."

"I have heard of the Temple of the Sun, Dator," replied Matai Shang, "but never have I heard that its prisoners could be released before the allotted year of their incarceration had elapsed. How, then, may you accomplish the impossible?"

"Access may be had to any cell of the temple at any time," replied Thurid. "Only Issus knew this; nor was it ever Issus' way to divulge more of her secrets than were necessary. By chance, after her death, I came upon an ancient plan of the temple, and there I found, plainly writ, the most minute directions for reaching the cells at any time.

"And more I learned—that many men had gone thither for Issus in the past, always on errands of death and torture to the prisoners; but those who thus learned the secret way were wont to die mysteriously immediately they had returned and made their reports to cruel Issus."

"Let us proceed, then," said Matai Shang at last. "I must trust you, yet at the same time you must trust me, for we are six to your one."

"I do not fear," replied Thurid, "nor need you. Our hatred of the common enemy is sufficient bond to insure our loyalty to each other, and after we have defiled the Princess of Helium there will be still greater reason for the maintenance of our allegiance—unless I greatly mistake the temper of her lord."

Matai Shang spoke to the paddlers. The boat moved on up the tributary.

It was with difficulty that I restrained myself from rushing upon them and slaying the two vile plotters; but quickly I saw the mad rashness of such an act, which would cut down the only man who could lead the way to Dejah Thoris' prison before the long Martian year had swung its interminable circle.

If he should lead Matai Shang to that hollowed spot, then, too, should he lead John Carter, Prince of Helium.

With silent paddle I swung slowly into the wake of the larger craft.

Under the Mountains

*

As we advanced up the river which winds beneath the Golden Cliffs out of the bowels of the Mountains of Otz to mingle its dark waters with the grim and mysterious Iss the faint glow which had appeared before us grew gradually into an all-enveloping radiance.

The river widened until it presented the aspect of a large lake whose vaulted dome, lighted by glowing phosphorescent rock, was splashed with the vivid rays of the diamond, the sapphire, the ruby, and the countless, nameless jewels of Barsoom which lay incrusted in the virgin gold which forms the major portion of these magnificent cliffs.

Beyond the lighted chamber of the lake was darkness—what lay behind the darkness I could not even guess.

To have followed the thern boat across the gleaming water would have been to invite instant detection, and so, though I was loath to permit Thurid to pass even for an instant beyond my sight, I was forced to wait in the shadows until the other boat had passed from my sight at the far extremity of the lake.

Then I paddled out upon the brilliant surface in the direction they had taken.

When, after what seemed an eternity, I reached the shadows at the upper end of the lake I found that the river issued from a low aperture, to pass beneath which it was necessary that I compel Woola to lie flat in the boat, and I, myself, must need bend double before the low roof cleared my head.

Immediately the roof rose again upon the other side, but no longer was the way brilliantly lighted. Instead only a feeble glow emanated from small and scattered patches of phosphorescent rock in wall and roof.

Directly before me the river ran into this smaller chamber through three separate arched openings.

Thurid and the therns were nowhere to be seen—into which of the dark holes had they disappeared? There was no means by which I might know, and so I chose the center opening as being as likely to lead me in the right direction as another.

Here the way was through utter darkness. The stream was narrow—so narrow that in the blackness I was constantly bumping first one rock wall and then another as the river wound hither and thither along its flinty bed.

Far ahead I presently heard a deep and sullen roar which increased in volume as I advanced, and then broke upon my ears with all the intensity of its mad fury as I swung round a sharp curve into a dimly lighted stretch of water.

Directly before me the river thundered down from above in a mighty waterfall that filled the narrow gorge from side to side, rising far above me several hundred feet—as magnificent a spectacle as I ever had seen.

But the roar—the awful, deafening roar of those tumbling waters penned in the rocky, subterranean vault! Had the fall not entirely blocked my further passage and shown me that I had followed the wrong course I believe that I should have fled anyway before the maddening tumult.

Thurid and the therns could not have come this way. By stumbling upon the wrong course I had lost the trail, and they had gained so much ahead of me that now I might not be able to find them before it was too late, if, in fact, I could find them at all.

It had taken several hours to force my way up to the falls against the strong current, and other hours would be required for the descent, although the pace would be much swifter.

With a sigh I turned the prow of my craft down stream, and with mighty strokes hastened with reckless speed through the dark and tortuous channel until once again I came to the chamber into which flowed the three branches of the river.

Two unexplored channels still remained from which to choose; nor was there any means by which I could judge which was the more likely to lead me to the plotters.

Never in my life, that I can recall, have I suffered such an agony of indecision. So much depended upon a correct choice; so much depended upon haste.

The hours that I had already lost might seal the fate of the incomparable Dejah Thoris were she not already dead—to sacrifice other hours, and maybe days in a fruitless exploration of another blind lead would unquestionably prove fatal.

Several times I essayed the right-hand entrance only to turn back as though warned by some strange intuitive sense that this was not the way. At last, convinced by the oft-recurring phenomenon, I cast my all upon the left-hand archway; yet it was with a lingering doubt that I turned a parting look at the sullen waters which rolled, dark and forbidding, from beneath the grim, low archway on the right.

And as I looked there came bobbing out upon the current from the Stygian darkness of the interior the shell of one of the great, succulent fruits of the sorapus tree.

I could scarce restrain a shout of elation as this silent, insensate messenger floated past me, on toward the Iss and Korus, for it told me that journeying Martians were above me on that very stream.

They had eaten of this marvelous fruit which nature concentrates within the hard shell of the sorapus nut, and having eaten had cast the husk overboard. It could have come from no others than the party I sought.

Quickly I abandoned all thought of the left-hand passage, and a moment later had turned into the right. The stream soon widened, and recurring areas of phosphorescent rock lighted my way.

I made good time, but was convinced that I was nearly a day behind those I was tracking. Neither Woola nor I had eaten since the previous day, but in so far as he was concerned it mattered but little, since practically all the animals of the dead sea bottoms of Mars are able to go for incredible periods without nourishment.

Nor did I suffer. The water of the river was sweet and cold, for it was unpolluted by decaying bodies—like the Iss—and as for food, why the mere thought that I was nearing my beloved princess raised me above every material want.

As I proceeded, the river became narrower and the current swift and turbulent—so swift in fact that it was with difficulty that I forced my craft upward at all. I could not have been making to exceed a hundred yards an hour when, at a bend, I was confronted by a series of rapids through which the river foamed and boiled at a terrific rate.

My heart sank within me. The sorapus nutshell had proved a false prophet, and, after all, my intuition had been correct—it was the left-hand channel that I should have followed.

Had I been a woman I should have wept. At my right was a great, slow-moving eddy that circled far beneath the cliff's overhanging side, and to rest my tired muscles before turning back I let my boat drift into its embrace.

I was almost prostrated by disappointment. It would mean another half-day's loss of time to retrace my way and take the only passage that yet remained unexplored. What hellish fate had led me to select from three possible avenues the two that were wrong?

As the lazy current of the eddy carried me slowly about the periphery of the watery circle my boat twice touched the rocky side of the river in the dark recess beneath the cliff.