Only Tars Tarkas, Thuvia, and I were left. The fatal marksmanship of the therns had snatched from our companions whatever slender chance they had of gaining the perilous freedom of the world without.

So soon as the last of the gruesome procession had disappeared the girl urged us to take up our flight once more.

She, too, had noted the questioning attitude of the thern who had borne Sator Throg away.

"It bodes no good for us, O Prince," she said. "For even though this fellow dared not chance accusing you in error, there be those above with power sufficient to demand a closer scrutiny, and that, Prince would indeed prove fatal."

I shrugged my shoulders. It seemed that in any event the outcome of our plight must end in death. I was refreshed from my sleep, but still weak from loss of blood. My wounds were painful. No medicinal aid seemed possible. How I longed for the almost miraculous healing power of the strange salves and lotions of the green Martian women. In an hour they would have had me as new.

I was discouraged. Never had a feeling of such utter hopelessness come over me in the face of danger. Then the long flowing, yellow locks of the Holy Thern, caught by some vagrant draught, blew about my face.

Might they not still open the way of freedom? If we acted in time, might we not even yet escape before the general alarm was sounded? We could at least try.

"What will the fellow do first, Thuvia?" I asked. "How long will it be before they may return for us?"

"He will go directly to the Father of Therns, old Matai Shang. He may have to wait for an audience, but since he is very high among the lesser therns, in fact as a thorian among them, it will not be long that Matai Shang will keep him waiting.

"Then if the Father of Therns puts credence in his story, another hour will see the galleries and chambers, the courts and gardens, filled with searchers."

"What we do then must be done within an hour. What is the best way, Thuvia, the shortest way out of this celestial Hades?"

"Straight to the top of the cliffs, Prince," she replied, "and then through the gardens to the inner courts. From there our way will lie within the temples of the therns and across them to the outer court. Then the ramparts-O Prince, it is hopeless. Ten thousand warriors could not hew a way to liberty from out this awful place.

"Since the beginning of time, little by little, stone by stone, have the therns been ever adding to the defences of their stronghold. A continuous line of impregnable fortifications circles the outer slopes of the Mountains of Otz.

"Within the temples that lie behind the ramparts a million fighting-men are ever ready. The courts and gardens are filled with slaves, with women and with children.

"None could go a stone's throw without detection."

"If there is no other way, Thuvia, why dwell upon the difficulties of this. We must face them."

"Can we not better make the attempt after dark?" asked Tars Tarkas. "There would seem to be no chance by day."

"There would be a little better chance by night, but even then the ramparts are well guarded; possibly better than by day. There are fewer abroad in the courts and gardens, though," said Thuvia.

"What is the hour?" I asked.

"It was midnight when you released me from my chains," said Thuvia. "Two hours later we reached the storeroom. There you slept for fourteen hours. It must now be nearly sundown again. Come, we will go to some nearby window in the cliff and make sure."

So saying, she led the way through winding corridors until at a sudden turn we came upon an opening which overlooked the Valley Dor.

At our right the sun was setting, a huge red orb, below the western range of Otz. A little below us stood the Holy Thern on watch upon his balcony. His scarlet robe of office was pulled tightly about him in anticipation of the cold that comes so suddenly with darkness as the sun sets. So rare is the atmosphere of Mars that it absorbs very little heat from the sun. During the daylight hours it is always extremely hot; at night it is intensely cold. Nor does the thin atmosphere refract the sun's rays or diffuse its light as upon Earth. There is no twilight on Mars. When the great orb of day disappears beneath the horizon the effect is precisely as that of the extinguishing of a single lamp within a chamber. From brilliant light you are plunged without warning into utter darkness. Then the moons come; the mysterious, magic moons of Mars, hurtling like monster meteors low across the face of the planet.

The declining sun lighted brilliantly the eastern banks of Korus, the crimson sward, the gorgeous forest. Beneath the trees we saw feeding many herds of plant men. The adults stood aloft upon their toes and their mighty tails, their talons pruning every available leaf and twig. It was then that I understood the careful trimming of the trees which had led me to form the mistaken idea when first I opened my eyes upon the grove that it was the playground of a civilized people.

As we watched, our eyes wandered to the rolling Iss, which issued from the base of the cliffs beneath us. Presently there emerged from the mountain a canoe laden with lost souls from the outer world. There were a dozen of them. All were of the highly civilized and cultured race of red men who are dominant on Mars.

The eyes of the herald upon the balcony beneath us fell upon the doomed party as soon as did ours. He raised his head and leaning far out over the low rail that rimmed his dizzy perch, voiced the shrill, weird wail that called the demons of this hellish place to the attack.

For an instant the brutes stood with stiffly erected ears, then they poured from the grove toward the river's bank, covering the distance with great, ungainly leaps.

The party had landed and was standing on the sward as the awful horde came in sight. There was a brief and futile effort of defence. Then silence as the huge, repulsive shapes covered the bodies of their victims and scores of sucking mouths fastened themselves to the flesh of their prey.

I turned away in disgust.

"Their part is soon over," said Thuvia. "The great white apes get the flesh when the plant men have drained the arteries. Look, they are coming now."

As I turned my eyes in the direction the girl indicated, I saw a dozen of the great white monsters running across the valley toward the river bank. Then the sun went down and darkness that could almost be felt engulfed us.

Thuvia lost no time in leading us toward the corridor which winds back and forth up through the cliffs toward the surface thousands of feet above the level on which we had been.

Twice great banths, wandering loose through the galleries, blocked our progress, but in each instance Thuvia spoke a low word of command and the snarling beasts slunk sullenly away.

"If you can dissolve all our obstacles as easily as you master these fierce brutes I can see no difficulties in our way," I said to the girl, smiling. "How do you do it?"

She laughed, and then shuddered.

"I do not quite know," she said. "When first I came here I angered Sator Throg, because I repulsed him. He ordered me to be thrown into one of the great pits in the inner gardens. It was filled with banths. In my own country I had been accustomed to command. Something in my voice, I do not know what, cowed the beasts as they sprang to attack me.

"Instead of tearing me to pieces, as Sator Throg had desired, they fawned at my feet. So greatly were Sator Throg and his friends amused by the sight that they kept me to train and handle the terrible creatures. I know them all by name. There are many of them wandering through these lower regions. They are the scavengers. Many prisoners die here in their chains. The banths solve the problem of sanitation, at least in this respect.

"In the gardens and temples above they are kept in pits. The therns fear them. It is because of the banths that they seldom venture below ground except as their duties call them."