"Go back the way thou camest, to the merciful maws of the children of the Tree of Life or the gleaming fangs of the great white apes, for there lies speedy surcease from suffering; but insist in your rash purpose to thread the mazes of the Golden Cliffs of the Mountains of Otz, past the ramparts of the impregnable fortresses of the Holy Therns, and upon your way Death in its most frightful form will overtake you-a death so horrible that even the Holy Therns themselves, who conceived both Life and Death, avert their eyes from its fiendishness and close their ears against the hideous shrieks of its victims.

"Go back, O fools, the way thou camest."

And then the awful laugh broke out from another part of the chamber.

"Most uncanny," I remarked, turning to Tars Tarkas.

"What shall we do?" he asked. "We cannot fight empty air; I would almost sooner return and face foes into whose flesh I may feel my blade bite and know that I am selling my carcass dearly before I go down to that eternal oblivion which is evidently the fairest and most desirable eternity that mortal man has the right to hope for."

"If, as you say, we cannot fight empty air, Tars Tarkas," I replied, "neither, on the other hand, can empty air fight us. I, who have faced and conquered in my time thousands of sinewy warriors and tempered blades, shall not be turned back by wind; nor no more shall you, Thark."

"But unseen voices may emanate from unseen and unseeable creatures who wield invisible blades," answered the green warrior.

"Rot, Tars Tarkas," I cried, "those voices come from beings as real as you or as I. In their veins flows lifeblood that may be let as easily as ours, and the fact that they remain invisible to us is the best proof to my mind that they are mortal; nor overly courageous mortals at that. Think you, Tars Tarkas, that John Carter will fly at the first shriek of a cowardly foe who dare not come out into the open and face a good blade?"

I had spoken in a loud voice that there might be no question that our would-be terrorizers should hear me, for I was tiring of this nerve-racking fiasco. It had occurred to me, too, that the whole business was but a plan to frighten us back into the valley of death from which we had escaped, that we might be quickly disposed of by the savage creatures there.

For a long period there was silence, then of a sudden a soft, stealthy sound behind me caused me to turn suddenly to behold a great many-legged banth creeping sinuously upon me.

The banth is a fierce beast of prey that roams the low hills surrounding the dead seas of ancient Mars. Like nearly all Martian animals it is almost hairless, having only a great bristly mane about its thick neck.

Its long, lithe body is supported by ten powerful legs, its enormous jaws are equipped, like those of the calot, or Martian hound, with several rows of long needle-like fangs; its mouth reaches to a point far back of its tiny ears, while its enormous, protruding eyes of green add the last touch of terror to its awful aspect.

As it crept toward me it lashed its powerful tail against its yellow sides, and when it saw that it was discovered it emitted the terrifying roar which often freezes its prey into momentary paralysis in the instant that it makes its spring.

And so it launched its great bulk toward me, but its mighty voice had held no paralysing terrors for me, and it met cold steel instead of the tender flesh its cruel jaws gaped so widely to engulf.

An instant later I drew my blade from the still heart of this great Barsoomian lion, and turning toward Tars Tarkas was surprised to see him facing a similar monster.

No sooner had he dispatched his than I, turning, as though drawn by the instinct of my guardian subconscious mind, beheld another of the savage denizens of the Martian wilds leaping across the chamber toward me.

From then on for the better part of an hour one hideous creature after another was launched upon us, springing apparently from the empty air about us.

Tars Tarkas was satisfied; here was something tangible that he could cut and slash with his great blade, while I, for my part, may say that the diversion was a marked improvement over the uncanny voices from unseen lips.

That there was nothing supernatural about our new foes was well evidenced by their howls of rage and pain as they felt the sharp steel at their vitals, and the very real blood which flowed from their severed arteries as they died the real death.

I noticed during the period of this new persecution that the beasts appeared only when our backs were turned; we never saw one really materialize from thin air, nor did I for an instant sufficiently lose my excellent reasoning faculties to be once deluded into the belief that the beasts came into the room other than through some concealed and well-contrived doorway.

Among the ornaments of Tars Tarkas' leather harness, which is the only manner of clothing worn by Martians other than silk capes and robes of silk and fur for protection from the cold after dark, was a small mirror, about the bigness of a lady's hand glass, which hung midway between his shoulders and his waist against his broad back.

Once as he stood looking down at a newly fallen antagonist my eyes happened to fall upon this mirror and in its shiny surface I saw pictured a sight that caused me to whisper:

"Move not, Tars Tarkas! Move not a muscle!"

He did not ask why, but stood like a graven image while my eyes watched the strange thing that meant so much to us.

What I saw was the quick movement of a section of the wall behind me. It was turning upon pivots, and with it a section of the floor directly in front of it was turning. It was as though you placed a visiting-card upon end on a silver dollar that you had laid flat upon a table, so that the edge of the card perfectly bisected the surface of the coin.

The card might represent the section of the wall that turned and the silver dollar the section of the floor. Both were so nicely fitted into the adjacent portions of the floor and wall that no crack had been noticeable in the dim light of the chamber.

As the turn was half completed a great beast was revealed sitting upon its haunches upon that part of the revolving floor that had been on the opposite side before the wall commenced to move; when the section stopped, the beast was facing toward me on our side of the partition-it was very simple.

But what had interested me most was the sight that the half-turned section had presented through the opening that it had made. A great chamber, well lighted, in which were several men and women chained to the wall, and in front of them, evidently directing and operating the movement of the secret doorway, a wicked-faced man, neither red as are the red men of Mars, nor green as are the green men, but white, like myself, with a great mass of flowing yellow hair.

The prisoners behind him were red Martians. Chained with them were a number of fierce beasts, such as had been turned upon us, and others equally as ferocious.

As I turned to meet my new foe it was with a heart considerably lightened.

"Watch the wall at your end of the chamber, Tars Tarkas," I cautioned, "it is through secret doorways in the wall that the brutes are loosed upon us." I was very close to him and spoke in a low whisper that my knowledge of their secret might not be disclosed to our tormentors.

As long as we remained each facing an opposite end of the apartment no further attacks were made upon us, so it was quite clear to me that the partitions were in some way pierced that our actions might be observed from without.

At length a plan of action occurred to me, and backing quite close to Tars Tarkas I unfolded my scheme in a low whisper, keeping my eyes still glued upon my end of the room.

The great Thark grunted his assent to my proposition when I had done, and in accordance with my plan commenced backing toward the wall which I faced while I advanced slowly ahead of him.