The huge beast, his tawny mane bristling around his hideous head, kept his eyes fixed upon another banth that charged erratically hither and thither, with shrill screams of pain, and horrid roars of hate and rage.

Carthoris quickly guessed that the second brute was the one he had blinded during the fight in the tunnel, but it was the dead thoat that centred his interest more than either of the savage carnivores.

The harness was still upon the body of the huge Martian mount, and Carthoris could not doubt but that this was the very animal upon which the green warrior had borne away Thuvia of Ptarth.

But where were the rider and his prisoner? The Prince of Helium shuddered as he thought upon the probability of the fate that had overtaken them.

Human flesh is the food most craved by the fierce Barsoomian lion, whose great carcass and giant thews require enormous quantities of meat to sustain them.

Two human bodies would have but whetted the creature's appetite, and that he had killed and eaten the green man and the red girl seemed only too likely to Carthoris. He had left the carcass of the mighty thoat to be devoured after having consumed the more tooth-some portion of his banquet.

Now the sightless banth, in its savage, aimless charging and counter-charging, had passed beyond the kill of its fellow, and there the light breeze that was blowing wafted the scent of new blood to its nostrils.

No longer were its movements erratic. With outstretched tail and foaming jaws it charged straight as an arrow, for the body of the thoat and the mighty creature of destruction that stood with forepaws upon the slate-grey side, waiting to defend its meat.

When the charging banth was twenty paces from the dead thoat the killer gave vent to its hideous challenge, and with a mighty spring leaped forward to meet it.

The battle that ensued awed even the warlike Barsoomian. The mad rending, the hideous and deafening roaring, the implacable savagery of the blood-stained beasts held him in the paralysis of fascination, and when it was over and the two creatures, their heads and shoulders torn to ribbons, lay with their dead jaws still buried in each other's bodies, Carthoris tore himself from the spell only by an effort of the will.

Hurrying to the side of the dead thoat, he searched for traces of the girl he feared had shared the thoat's fate, but nowhere could he discover anything to confirm his fears.

With slightly lightened heart he started out to explore the valley, but scarce a dozen steps had he taken when the glistening of a jewelled bauble lying on the sward caught his eye.

As he picked it up his first glance showed him that it was a woman's hair ornament, and emblazoned upon it was the insignia of the royal house of Ptarth.

But, sinister discovery, blood, still wet, splotched the magnificent jewels of the setting.

Carthoris half choked as the dire possibilities which the thing suggested presented themselves to his imagination. Yet he could not, would not believe it.

It was impossible that that radiant creature could have met so hideous an end. It was incredible that the glorious Thuvia should ever cease to be.

Upon his already jewel-encrusted harness, to the strap that crossed his great chest beneath which beat his loyal heart, Carthoris, Prince of Helium, fastened the gleaming thing that Thuvia of Ptarth had worn, and wearing, had made holy to the Heliumite.

Then he proceeded upon his way into the heart of the unknown valley.

For the most part the giant trees shut off his view to any but the most limited distances. Occasionally he caught glimpses of the towering hills that bounded the valley upon every side, and though they stood out clear beneath the light of the two moons, he knew that they were far off, and that the extent of the valley was immense.

For half the night he continued his search, until presently he was brought to a sudden halt by the distant sound of squealing thoats.

Guided by the noise of these habitually angry beasts, he stole forward through the trees until at last he came upon a level, treeless plain, in the centre of which a mighty city reared its burnished domes and vividly coloured towers.

About the walled city the red man saw a huge encampment of the green warriors of the dead sea-bottoms, and as he let his eyes rove carefully over the city he realized that here was no deserted metropolis of a dead past.

But what city could it be? His studies had taught him that in this little-explored portion of Barsoom the fierce tribe of Torquasian green men ruled supreme, and that as yet no red man had succeeded in piercing to the heart of their domain to return again to the world of civilization.

The men of Torquas had perfected huge guns with which their uncanny marksmanship had permitted them to repulse the few determined efforts that near-by red nations had made to explore their country by means of battle fleets of airships.

That he was within the boundary of Torquas, Carthoris was sure, but that there existed there such a wondrous city he never had dreamed, nor had the chronicles of the past even hinted at such a possibility, for the Torquasians were known to live, as did the other green men of Mars, within the deserted cities that dotted the dying planet, nor ever had any green horde built so much as a single edifice, other than the low-walled incubators where their young are hatched by the sun's heat.

The encircling camp of green warriors lay about five hundred yards from the city's walls. Between it and the city was no semblance of breastwork or other protection against rifle or cannon fire; yet distinctly now in the light of the rising sun Carthoris could see many figures moving along the summit of the high wall, and upon the roof tops beyond.

That they were beings like himself he was sure, though they were at too great distance from him for him to be positive that they were red men.

Almost immediately after sunrise the green warriors commenced firing upon the little figures upon the wall. To Carthoris' surprise the fire was not returned, but presently the last of the city's inhabitants had sought shelter from the weird marksmanship of the green men, and no further sign of life was visible beyond the wall.

Then Carthoris, keeping within the shelter of the trees that fringed the plain, began circling the rear of the besiegers' line, hoping against hope that somewhere he would obtain sight of Thuvia of Ptarth, for even now he could not believe that she was dead.

That he was not discovered was a miracle, for mounted warriors were constantly riding back and forth from the camp into the forest; but the long day wore on and still he continued his seemingly fruitless quest, until, near sunset, he came opposite a mighty gate in the city's western wall.

Here seemed to be the principal force of the attacking horde. Here a great platform had been erected whereon Carthoris could see squatting a huge green warrior, surrounded by others of his kind.

This, then, must be the notorious Hortan Gur, Jeddak of Torquas, the fierce old ogre of the south-western hemisphere, as only for a jeddak are platforms raised in temporary camps or upon the march by the green hordes of Barsoom.

As the Heliumite watched he saw another green warrior push his way forward toward the rostrum. Beside him he dragged a captive, and as the surrounding warriors parted to let the two pass, Carthoris caught a fleeting glimpse of the prisoner.

His heart leaped in rejoicing. Thuvia of Ptarth still lived!

It was with difficulty that Carthoris restrained the impulse to rush forward to the side of the Ptarthian princess; but in the end his better judgment prevailed, for in the face of such odds he knew that he should have been but throwing away, uselessly, any future opportunity he might have to succour her.