Now I realized why the black pirate had kept me engrossedwith his strange tale. For miles he had sensed the approachof succour, and but for that single tell-tale glance thebattleship would have been directly above us in another moment,and the boarding party which was doubtless even now swingingin their harness from the ship's keel, would have swarmed our deck,placing my rising hope of escape in sudden and total eclipse.

I was too old a hand in aerial warfare to be at a lossnow for the right manoeuvre. Simultaneously I reversed theengines and dropped the little vessel a sheer hundred feet.

Above my head I could see the dangling forms of theboarding party as the battleship raced over us. Then I rose ata sharp angle, throwing my speed lever to its last notch.

Like a bolt from a crossbow my splendid craft shot itssteel prow straight at the whirring propellers of the giantabove us. If I could but touch them the huge bulk wouldbe disabled for hours and escape once more possible.

At the same instant the sun shot above the horizon,disclosing a hundred grim, black faces peering overthe stern of the battleship upon us.

At sight of us a shout of rage went up from a hundred throats.Orders were shouted, but it was too late to save thegiant propellers, and with a crash we rammed them.

Instantly with the shock of impact I reversed my engine,but my prow was wedged in the hole it had made in thebattleship's stern. Only a second I hung there before tearingaway, but that second was amply long to swarm my deckwith black devils.

There was no fight. In the first place there was no roomto fight. We were simply submerged by numbers. Then asswords menaced me a command from Xodar stayed the handsof his fellows.

"Secure them," he said, "but do not injure them."

Several of the pirates already had released Xodar. He nowpersonally attended to my disarming and saw that I wasproperly bound. At least he thought that the binding wassecure. It would have been had I been a Martian, but I hadto smile at the puny strands that confined my wrists. Whenthe time came I could snap them as they had been cottonstring.

The girl they bound also, and then they fastened us together. In the meantime they had brought our craft alongside thedisabled battleship, and soon we were transported to the latter's deck.

Fully a thousand black men manned the great engine of destruction.Her decks were crowded with them as they pressed forward as far asdiscipline would permit to get a glimpse of their captives.

The girl's beauty elicited many brutal comments and vulgar jests.It was evident that these self-thought supermen were far inferiorto the red men of Barsoom in refinement and in chivalry.

My close-cropped black hair and thern complexion werethe subjects of much comment. When Xodar told his fellownobles of my fighting ability and strange origin they crowdedabout me with numerous questions.

The fact that I wore the harness and metal of a thern whohad been killed by a member of my party convinced themthat I was an enemy of their hereditary foes, and placedme on a better footing in their estimation.

Without exception the blacks were handsome men, andwell built. The officers were conspicuous through thewondrous magnificence of their resplendent trappings.Many harnesses were so encrusted with gold, platinum, silverand precious stones as to entirely hide the leather beneath.

The harness of the commanding officer was a solid massof diamonds. Against the ebony background of his skin theyblazed out with a peculiarly accentuated effulgence. The wholescene was enchanting. The handsome men; the barbaric splendourof the accoutrements; the polished skeel wood of the deck; thegloriously grained sorapus of the cabins, inlaid with pricelessjewels and precious metals in intricate and beautiful design;the burnished gold of hand rails; the shining metal of the guns.

Phaidor and I were taken below decks, where, still fast bound,we were thrown into a small compartment which contained asingle port-hole. As our escort left us they barred thedoor behind them.

We could hear the men working on the broken propellers,and from the port-hole we could see that the vessel wasdrifting lazily toward the south.

For some time neither of us spoke. Each was occupiedwith his own thoughts. For my part I was wondering as tothe fate of Tars Tarkas and the girl, Thuvia.

Even if they succeeded in eluding pursuit they must eventuallyfall into the hands of either red men or green, and as fugitivesfrom the Valley Dor they could look for but little else than aswift and terrible death.

How I wished that I might have accompanied them. Itseemed to me that I could not fail to impress upon theintelligent red men of Barsoom the wicked deception that acruel and senseless superstition had foisted upon them.

Tardos Mors would believe me. Of that I was positive. Andthat he would have the courage of his convictions my knowledgeof his character assured me. Dejah Thoris would believe me.Not a doubt as to that entered my head. Then there werea thousand of my red and green warrior friends whomI knew would face eternal damnation gladly for my sake.Like Tars Tarkas, where I led they would follow.

My only danger lay in that should I ever escape the blackpirates it might be to fall into the hands of unfriendly redor green men. Then it would mean short shrift for me.

Well, there seemed little to worry about on that score, for thelikelihood of my ever escaping the blacks was extremely remote.

The girl and I were linked together by a rope which permittedus to move only about three or four feet from each other.When we had entered the compartment we had seated ourselvesupon a low bench beneath the porthole. The bench was theonly furniture of the room. It was of sorapus wood.The floor, ceiling and walls were of carborundum aluminum,a light, impenetrable composition extensively utilizedin the construction of Martian fighting ships.

As I had sat meditating upon the future my eyes hadbeen riveted upon the port-hole which was just level withthem as I sat. Suddenly I looked toward Phaidor. She wasregarding me with a strange expression I had not before seenupon her face. She was very beautiful then.

Instantly her white lids veiled her eyes, and I thought Idiscovered a delicate flush tingeing her cheek. Evidently shewas embarrassed at having been detected in the act of staringat a lesser creature, I thought.

"Do you find the study of the lower orders interesting?"I asked, laughing.

She looked up again with a nervous but relieved little laugh.

"Oh very," she said, "especially when they have such excellent profiles."

It was my turn to flush, but I did not. I felt that she waspoking fun at me, and I admired a brave heart that could lookfor humour on the road to death, and so I laughed with her.

"Do you know where we are going?" she said.

"To solve the mystery of the eternal hereafter, I imagine," I replied.

"I am going to a worse fate than that," she said, with a little shudder.

"What do you mean?"

"I can only guess," she replied, "since no thern damsel ofall the millions that have been stolen away by black piratesduring the ages they have raided our domains has ever returnedto narrate her experiences among them. That they never take aman prisoner lends strength to the belief that the fate of thegirls they steal is worse than death."

"Is it not a just retribution?" I could not help but ask.

"What do you mean?"

"Do not the therns themselves do likewise with the poor creatureswho take the voluntary pilgrimage down the River of Mystery? Was not Thuvia for fifteen years a plaything and a slave?Is it less than just that you should suffer as you havecaused others to suffer?"

"You do not understand," she replied. "We therns are a holy race.It is an honour to a lesser creature to be a slave among us.Did we not occasionally save a few of the lower orders thatstupidly float down an unknown river to an unknown end allwould become the prey of the plant men and the apes."

"But do you not by every means encourage the superstitionamong those of the outside world?" I argued. "That is thewickedest of your deeds. Can you tell me why you fosterthe cruel deception?"

"All life on Barsoom," she said, "is created solely for thesupport of the race of therns. How else could we live didthe outer world not furnish our labour and our food? Thinkyou that a thern would demean himself by labour?"

"It is true then that you eat human flesh?" I asked in horror.

She looked at me in pitying commiseration for my ignorance.

"Truly we eat the flesh of the lower orders. Do not you also?"

"The flesh of beasts, yes," I replied, "but not the flesh of man."

"As man may eat of the flesh of beasts, so may gods eat ofthe flesh of man. The Holy Therns are the gods of Barsoom."

I was disgusted and I imagine that I showed it.

"You are an unbeliever now," she continued gently, "butshould we be fortunate enough to escape the clutches of theblack pirates and come again to the court of Matai Shang Ithink that we shall find an argument to convince you of theerror of your ways. And--," she hesitated, "perhaps we shallfind a way to keep you as--as--one of us."

Again her eyes dropped to the floor, and a faint coloursuffused her cheek. I could not understand her meaning; nordid I for a long time. Dejah Thoris was wont to say that insome things I was a veritable simpleton, and I guess thatshe was right.

"I fear that I would ill requite your father's hospitality,"I answered, "since the first thing that I should do were I athern would be to set an armed guard at the mouth of theRiver Iss to escort the poor deluded voyagers back tothe outer world. Also should I devote my life to theextermination of the hideous plant men and their horriblecompanions, the great white apes."

She looked at me really horror struck.

"No, no," she cried, "you must not say such terriblysacrilegious things--you must not even think them.Should they ever guess that you entertained suchfrightful thoughts, should we chance to regain thetemples of the therns, they would mete out a frightfuldeath to you. Not even my--my--" Again she flushed,and started over. "Not even I could save you."

I said no more. Evidently it was useless. She was even moresteeped in superstition than the Martians of the outer world.They only worshipped a beautiful hope for a life of loveand peace and happiness in the hereafter. The thernsworshipped the hideous plant men and the apes, or atleast they reverenced them as the abodes of the departedspirits of their own dead.

At this point the door of our prison opened to admit Xodar.

He smiled pleasantly at me, and when he smiled his expressionwas kindly--anything but cruel or vindictive.

"Since you cannot escape under any circumstances," he said,"I cannot see the necessity for keeping you confined below.I will cut your bonds and you may come on deck. You willwitness something very interesting, and as you never shallreturn to the outer world it will do no harm to permit youto see it. You will see what no other than the First Bornand their slaves know the existence of--the subterraneanentrance to the Holy Land, to the real heaven of Barsoom.

"It will be an excellent lesson for this daughter of the therns,"he added, "for she shall see the Temple of Issus, and Issus,perchance, shall embrace her."

Phaidor's head went high.

"What blasphemy is this, dog of a pirate?" she cried."Issus would wipe out your entire breed an' you evercame within sight of her temple."

"You have much to learn, thern," replied Xodar, with anugly smile, "nor do I envy you the manner in which youwill learn it."

As we came on deck I saw to my surprise that the vesselwas passing over a great field of snow and ice. As far as theeye could reach in any direction naught else was visible.

There could be but one solution to the mystery. We wereabove the south polar ice cap. Only at the poles of Mars isthere ice or snow upon the planet. No sign of life appearedbelow us. Evidently we were too far south even for the greatfur-bearing animals which the Martians so delight in hunting.

Xodar was at my side as I stood looking out over the ship's rail.

"What course?" I asked him.

"A little west of south," he replied. "You will see the OtzValley directly. We shall skirt it for a few hundred miles."

"The Otz Valley!" I exclaimed; "but, man, is not there wherelie the domains of the therns from which I but just escaped?"

"Yes," answered Xodar. "You crossed this ice field lastnight in the long chase that you led us. The Otz Valley liesin a mighty depression at the south pole. It is sunk thousandsof feet below the level of the surrounding country, like agreat round bowl. A hundred miles from its northern boundaryrise the Otz Mountains which circle the inner Valley ofDor, in the exact centre of which lies the Lost Sea of Korus.On the shore of this sea stands the Golden Temple of Issusin the Land of the First Born. It is there that we are bound."

As I looked I commenced to realize why it was that inall the ages only one had escaped from the Valley Dor. Myonly wonder was that even the one had been successful. Tocross this frozen, wind-swept waste of bleak ice alone andon foot would be impossible.

"Only by air boat could the journey be made," I finished aloud.

"It was thus that one did escape the therns in bygonetimes; but none has ever escaped the First Born," said Xodar,with a touch of pride in his voice.

We had now reached the southernmost extremity of thegreat ice barrier. It ended abruptly in a sheer wall thousandsof feet high at the base of which stretched a level valley,broken here and there by low rolling hills and little clumpsof forest, and with tiny rivers formed by the melting of theice barrier at its base.

Once we passed far above what seemed to be a deepcanyon-like rift stretching from the ice wall on the northacross the valley as far as the eye could reach. "That is thebed of the River Iss," said Xodar. "It runs far beneath theice field, and below the level of the Valley Otz, but its canyonis open here."

Presently I descried what I took to be a village, and pointingit out to Xodar asked him what it might be.

"It is a village of lost souls," he answered, laughing. "Thisstrip between the ice barrier and the mountains is consideredneutral ground. Some turn off from their voluntary pilgrimagedown the Iss, and, scaling the awful walls of its canyon belowus, stop in the valley. Also a slave now and then escapesfrom the therns and makes his way hither.

"They do not attempt to recapture such, since there is noescape from this outer valley, and as a matter of fact theyfear the patrolling cruisers of the First Born too much toventure from their own domains.

"The poor creatures of this outer valley are not molestedby us since they have nothing that we desire, nor are theynumerically strong enough to give us an interesting fight--sowe too leave them alone.

"There are several villages of them, but they have increasedin numbers but little in many years since they are alwayswarring among themselves."

Now we swung a little north of west, leaving the valley oflost souls, and shortly I discerned over our starboard bowwhat appeared to be a black mountain rising from the desolatewaste of ice. It was not high and seemed to have a flat top.

Xodar had left us to attend to some duty on the vessel,and Phaidor and I stood alone beside the rail. The girl hadnot once spoken since we had been brought to the deck.

"Is what he has been telling me true?" I asked her.

"In part, yes," she answered. "That about the outer valleyis true, but what he says of the location of the Templeof Issus in the centre of his country is false. If it is notfalse--" she hesitated. "Oh it cannot be true, it cannot betrue. For if it were true then for countless ages have mypeople gone to torture and ignominious death at the handsof their cruel enemies, instead of to the beautiful Life Eternalthat we have been taught to believe Issus holds for us."

"As the lesser Barsoomians of the outer world have beenlured by you to the terrible Valley Dor, so may it be that thetherns themselves have been lured by the First Born to anequally horrid fate," I suggested. "It would be a stern andawful retribution, Phaidor; but a just one."

"I cannot believe it," she said.

"We shall see," I answered, and then we fell silent again for wewere rapidly approaching the black mountains, which in someindefinable way seemed linked with the answer to our problem.

As we neared the dark, truncated cone the vessel's speed wasdiminished until we barely moved. Then we topped the crestof the mountain and below us I saw yawning the mouth of ahuge circular well, the bottom of which was lost in inky blackness.

The diameter of this enormous pit was fully a thousand feet.The walls were smooth and appeared to be composed of ablack, basaltic rock.

For a moment the vessel hovered motionless directly abovethe centre of the gaping void, then slowly she began to settleinto the black chasm. Lower and lower she sank until asdarkness enveloped us her lights were thrown on and in thedim halo of her own radiance the monster battleship droppedon and on down into what seemed to me must be the verybowels of Barsoom.

For quite half an hour we descended and then the shaftterminated abruptly in the dome of a mighty subterraneanworld. Below us rose and fell the billows of a buried sea. Aphosphorescent radiance illuminated the scene. Thousands ofships dotted the bosom of the ocean. Little islands rose hereand there to support the strange and colourless vegetation ofthis strange world.

Slowly and with majestic grace the battleship dropped untilshe rested on the water. Her great propellers had beendrawn and housed during our descent of the shaft and intheir place had been run out the smaller but more powerfulwater propellers. As these commenced to revolve theship took up its journey once more, riding the new elementas buoyantly and as safely as she had the air.

Phaidor and I were dumbfounded. Neither had either heard ordreamed that such a world existed beneath the surface of Barsoom.

Nearly all the vessels we saw were war craft. There werea few lighters and barges, but none of the great merchantmensuch as ply the upper air between the cities of the outer world.

"Here is the harbour of the navy of the First Born,"said a voice behind us, and turning we saw Xodar watchingus with an amused smile on his lips.

"This sea," he continued, "is larger than Korus. It receivesthe waters of the lesser sea above it. To keep it from fillingabove a certain level we have four great pumping stations thatforce the oversupply back into the reservoirs far north from whichthe red men draw the water which irrigates their farm lands."

A new light burst on me with this explanation. The redmen had always considered it a miracle that caused greatcolumns of water to spurt from the solid rock of theirreservoir sides to increase the supply of the preciousliquid which is so scarce in the outer world of Mars.

Never had their learned men been able to fathom thesecret of the source of this enormous volume of water.As ages passed they had simply come to accept it as amatter of course and ceased to question its origin.

We passed several islands on which were strangely shapedcircular buildings, apparently roofless, and pierced midwaybetween the ground and their tops with small, heavily barredwindows. They bore the earmarks of prisons, which werefurther accentuated by the armed guards who squatted onlow benches without, or patrolled the short beach lines.

Few of these islets contained over an acre of ground, butpresently we sighted a much larger one directly ahead. Thisproved to be our destination, and the great ship was soonmade fast against the steep shore.

Xodar signalled us to follow him and with a half-dozenofficers and men we left the battleship and approached alarge oval structure a couple of hundred yards from the shore.

"You shall soon see Issus," said Xodar to Phaidor. "Thefew prisoners we take are presented to her. Occasionally sheselects slaves from among them to replenish the ranks of herhandmaidens. None serves Issus above a single year," andthere was a grim smile on the black's lips that lent a crueland sinister meaning to his simple statement.

Phaidor, though loath to believe that Issus was allied tosuch as these, had commenced to entertain doubts andfears. She clung very closely to me, no longer the prouddaughter of the Master of Life and Death upon Barsoom, but ayoung and frightened girl in the power of relentless enemies.

The building which we now entered was entirely roofless.In its centre was a long tank of water, set below the level ofthe floor like the swimming pool of a natatorium. Near oneside of the pool floated an odd-looking black object. Whetherit were some strange monster of these buried waters, or aqueer raft, I could not at once perceive.

We were soon to know, however, for as we reached theedge of the pool directly above the thing, Xodar cried out afew words in a strange tongue. Immediately a hatch coverwas raised from the surface of the object, and a blackseaman sprang from the bowels of the strange craft.

Xodar addressed the seaman.

"Transmit to your officer," he said, "the commands ofDator Xodar. Say to him that Dator Xodar, with officersand men, escorting two prisoners, would be transported tothe gardens of Issus beside the Golden Temple."

"Blessed be the shell of thy first ancestor, most noble Dator,"replied the man. "It shall be done even as thou sayest," andraising both hands, palms backward, above his head after themanner of salute which is common to all races of Barsoom,he disappeared once more into the entrails of his ship.

A moment later an officer resplendent in the gorgeous trappingsof his rank appeared on deck and welcomed Xodar to the vessel,and in the latter's wake we filed aboard and below.

The cabin in which we found ourselves extended entirelyacross the ship, having port-holes on either side below thewater line. No sooner were all below than a number ofcommands were given, in accordance with which the hatchwas closed and secured, and the vessel commenced to vibrateto the rhythmic purr of its machinery.

"Where can we be going in such a tiny pool of water?" asked Phaidor.

"Not up," I replied, "for I noticed particularly that while thebuilding is roofless it is covered with a strong metal grating."

"Then where?" she asked again.

"From the appearance of the craft I judge we are going down," I replied.

Phaidor shuddered. For such long ages have the watersof Barsoom's seas been a thing of tradition only that eventhis daughter of the therns, born as she had been withinsight of Mars' only remaining sea, had the same terror ofdeep water as is a common attribute of all Martians.

Presently the sensation of sinking became very apparent.We were going down swiftly. Now we could hear the water rushingpast the port-holes, and in the dim light that filtered throughthem to the water beyond the swirling eddies were plainly visible.

Phaidor grasped my arm.

"Save me!" she whispered. "Save me and your everywish shall be granted. Anything within the power of the HolyTherns to give will be yours. Phaidor--" she stumbled a littlehere, and then in a very low voice, "Phaidor already is yours."

I felt very sorry for the poor child, and placed my handover hers where it rested on my arm. I presume my motivewas misunderstood, for with a swift glance about the apartmentto assure herself that we were alone, she threw both her armsabout my neck and dragged my face down to hers.