When the light of day broke upon the little craft to whose deck the Princess of Ptarth had been snatched from her father's garden, Thuvia saw that the night had wrought a change in her abductors.

No longer did their trappings gleam with the metal of Dusar, but instead there was emblazoned there the insignia of the Prince of Helium.

The girl felt renewed hope, for she could not believe that in the heart of Carthoris could lie intent to harm her.

She spoke to the warrior squatting before the control board.

"Last night you wore the trappings of a Dusarian," she said. "Now your metal is that of Helium. What means it?"

The man looked at her with a grin.

"The Prince of Helium is no fool," he said.

Just then an officer emerged from the tiny cabin. He reprimanded the warrior for conversing with the prisoner, nor would he himself reply to any of her inquiries.

No harm was offered her during the journey, and so they came at last to their destination with the girl no wiser as to her abductors or their purpose than at first.

Here the flier settled slowly into the plaza of one of those mute monuments of Mars' dead and forgotten past — the deserted cities that fringe the sad ochre sea-bottoms where once rolled the mighty floods upon whose bosoms moved the maritime commerce of the peoples that are gone for ever.

Thuvia of Ptarth was no stranger to such places. During her wanderings in search of the River Iss, that time she had set out upon what, for countless ages, had been the last, long pilgrimage of Martians, toward the Valley Dor, where lies the Lost Sea of Korus, she had encountered several of these sad reminders of the greatness and the glory of ancient Barsoom.

And again, during her flight from the temples of the Holy Therns with Tars Tarkas, Jeddak of Thark, she had seen them, with their weird and ghostly inmates, the great white apes of Barsoom.

She knew, too, that many of them were used now by the nomadic tribes of green men, but that among them all was no city that the red men did not shun, for without exception they stood amidst vast, waterless tracts, unsuited for the continued sustenance of the dominant race of Martians.

Why, then, should they be bringing her to such a place? There was but a single answer. Such was the nature of their work that they must needs seek the seclusion that a dead city afforded. The girl trembled at thought of her plight.

For two days her captors kept her within a huge palace that even in decay reflected the splendour of the age which its youth had known.

Just before dawn on the third day she had been aroused by the voices of two of her abductors.

"He should be here by dawn," one was saying. "Have her in readiness upon the plaza — else he will never land. The moment he finds that he is in a strange country he will turn about — methinks the prince's plan is weak in this one spot."

"There was no other way," replied the other. "It is wondrous work to get them both here at all, and even if we do not succeed in luring him to the ground, we shall have accomplished much."

Just then the speaker caught the eyes of Thuvia upon him, revealed by the quick-moving patch of light cast by Thuria in her mad race through the heavens.

With a quick sign to the other, he ceased speaking, and advancing toward the girl, motioned her to rise. Then he led her out into the night toward the centre of the great plaza.

"Stand here," he commanded, "until we come for you. We shall be watching, and should you attempt to escape it will go ill with you — much worse than death. Such are the prince's orders."

Then he turned and retraced his steps toward the palace, leaving her alone in the midst of the unseen terrors of the haunted city, for in truth these places are haunted in the belief of many Martians who still cling to an ancient superstition which teaches that the spirits of Holy Therns who die before their allotted one thousand years, pass, on occasions, into the bodies of the great white apes.

To Thuvia, however, the real danger of attack by one of these ferocious, manlike beasts was quite sufficient. She no longer believed in the weird soul transmigration that the therns had taught her before she was rescued from their clutches by John Carter; but she well knew the horrid fate that awaited her should one of the terrible beasts chance to spy her during its nocturnal prowlings.

What was that?

Surely she could not be mistaken. Something had moved, stealthily, in the shadow of one of the great monoliths that line the avenue where it entered the plaza opposite her!

Thar Ban, jed among the hordes of Torquas, rode swiftly across the ochre vegetation of the dead sea-bottom toward the ruins of ancient Aaanthor.

He had ridden far that night, and fast, for he had but come from the despoiling of the incubator of a neighbouring green horde with which the hordes of Torquas were perpetually warring.

His giant thoat was far from jaded, yet it would be well, thought Thar Ban, to permit him to graze upon the ochre moss which grows to greater height within the protected courtyards of deserted cities, where the soil is richer than on the sea-bottoms, and the plants partly shaded from the sun during the cloudless Martian day.

Within the tiny stems of this dry-seeming plant is sufficient moisture for the needs of the huge bodies of the mighty thoats, which can exist for months without water, and for days without even the slight moisture which the ochre moss contains.

As Thar Ban rode noiselessly up the broad avenue which leads from the quays of Aaanthor to the great central plaza, he and his mount might have been mistaken for spectres from a world of dreams, so grotesque the man and beast, so soundless the great thoat's padded, nailless feet upon the moss-grown flagging of the ancient pavement.

The man was a splendid specimen of his race. Fully fifteen feet towered his great height from sole to pate. The moonlight glistened against his glossy green hide, sparkling the jewels of his heavy harness and the ornaments that weighted his four muscular arms, while the upcurving tusks that protruded from his lower jaw gleamed white and terrible.

At the side of his thoat were slung his long radium rifle and his great, forty-foot, metal-shod spear, while from his own harness depended his long-sword and his short-sword, as well as his lesser weapons.

His protruding eyes and antennae-like ears were turning constantly hither and thither, for Thar Ban was yet in the country of the enemy, and, too, there was always the menace of the great white apes, which, John Carter was wont to say, are the only creatures that can arouse in the breasts of these fierce denizens of the dead sea-bottoms even the remotest semblance of fear.

As the rider neared the plaza, he reined suddenly in. His slender, tubular ears pointed rigidly forward. An unwonted sound had reached them. Voices! And where there were voices, outside of Torquas, there, too, were enemies. All the world of wide Barsoom contained naught but enemies for the fierce Torquasians.

Thar Ban dismounted. Keeping in the shadows of the great monoliths that line the Avenue of Quays of sleeping Aaanthor, he approached the plaza. Directly behind him, as a hound at heel, came the slate-grey thoat, his white belly shadowed by his barrel, his vivid yellow feet merging into the yellow of the moss beneath them.

In the centre of the plaza Thar Ban saw the figure of a red woman. A red warrior was conversing with her. Now the man turned and retraced his steps toward the palace at the opposite side of the plaza.

Thar Ban watched until he had disappeared within the yawning portal. Here was a captive worth having! Seldom did a female of their hereditary enemies fall to the lot of a green man. Thar Ban licked his thin lips.

Thuvia of Ptarth watched the shadow behind the monolith at the opening to the avenue opposite her. She hoped that it might be but the figment of an overwrought imagination.

But no! Now, clearly and distinctly, she saw it move. It came from behind the screening shelter of the ersite shaft.

The sudden light of the rising sun fell upon it. The girl trembled. The thing was a huge green warrior!

Swiftly it sprang toward her. She screamed and tried to flee; but she had scarce turned toward the palace when a giant hand fell upon her arm, she was whirled about, and half dragged, half carried toward a huge thoat that was slowly grazing out of the avenue's mouth on to the ochre moss of the plaza.

At the same instant she turned her face upward toward the whirring sound of something above her, and there she saw a swift flier dropping toward her, the head and shoulders of a man leaning far over the side; but the man's features were deeply shadowed, so that she did not recognize them.

Now from behind her came the shouts of her red abductors. They were racing madly after him who dared to steal what they already had stolen.

As Thar Ban reached the side of his mount he snatched his long radium rifle from its boot, and, wheeling, poured three shots into the oncoming red men.

Such is the uncanny marksmanship of these Martian savages that three red warriors dropped in their tracks as three projectiles exploded in their vitals.

The others halted, nor did they dare return the fire for fear of wounding the girl.

Then Thar Ban vaulted to the back of his thoat, Thuvia of Ptarth still in his arms, and with a savage cry of triumph disappeared down the black canyon of the Avenue of Quays between the sullen palaces of forgotten Aaanthor.

Carthoris' flier had not touched the ground before he had sprung from its deck to race after the swift thoat, whose eight long legs were sending it down the avenue at the rate of an express train; but the men of Dusar who still remained alive had no mind to permit so valuable a capture to escape them.

They had lost the girl. That would be a difficult thing to explain to Astok; but some leniency might be expected could they carry the Prince of Helium to their master instead.

So the three who remained set upon Carthoris with their long-swords, crying to him to surrender; but they might as successfully have cried aloud to Thuria to cease her mad hurtling through the Barsoomian sky, for Carthoris of Helium was a true son of the Warlord of Mars and his incomparable Dejah Thoris.

Carthoris' long-sword had been already in his hand as he leaped from the deck of the flier, so the instant that he realized the menace of the three red warriors, he wheeled to face them, meeting their onslaught as only John Carter himself might have done.

So swift his sword, so mighty and agile his half-earthly muscles, that one of his opponents was down, crimsoning the ochre moss with his life-blood, when he had scarce made a single pass at Carthoris.

Now the two remaining Dusarians rushed simultaneously upon the Heliumite. Three long-swords clashed and sparkled in the moonlight, until the great white apes, roused from their slumbers, crept to the lowering windows of the dead city to view the bloody scene beneath them.

Thrice was Carthoris touched, so that the red blood ran down his face, blinding him and dyeing his broad chest. With his free hand he wiped the gore from his eyes, and with the fighting smile of his father touching his lips, leaped upon his antagonists with renewed fury.

A single cut of his heavy sword severed the head of one of them, and then the other, backing away clear of that point of death, turned and fled toward the palace at his back.

Carthoris made no step to pursue. He had other concern than the meting of even well-deserved punishment to strange men who masqueraded in the metal of his own house, for he had seen that these men were tricked out in the insignia that marked his personal followers.

Turning quickly toward his flier, he was soon rising from the plaza in pursuit of Thar Ban.

The red warrior whom he had put to flight turned in the entrance to the palace, and, seeing Carthoris' intent, snatched a rifle from those that he and his fellows had left leaning against the wall as they had rushed out with drawn swords to prevent the theft of their prisoner.

Few red men are good shots, for the sword is their chosen weapon; so now as the Dusarian drew bead upon the rising flier, and touched the button upon his rifle's stock, it was more to chance than proficiency that he owed the partial success of his aim.

The projectile grazed the flier's side, the opaque coating breaking sufficiently to permit daylight to strike in upon the powder phial within the bullet's nose. There was a sharp explosion. Carthoris felt his craft reel drunkenly beneath him, and the engine stopped.

The momentum the air boat had gained carried her on over the city toward the sea-bottom beyond.

The red warrior in the plaza fired several more shots, none of which scored. Then a lofty minaret shut the drifting quarry from his view.

In the distance before him Carthoris could see the green warrior bearing Thuvia of Ptarth away upon his mighty thoat. The direction of his flight was toward the north-west of Aaanthor, where lay a mountainous country little known to red men.

The Heliumite now gave his attention to his injured craft. A close examination revealed the face that one of the buoyancy tanks had been punctured, but the engine itself was uninjured.

A splinter from the projectile had damaged one of the control levers beyond the possibility of repair outside a machine shop; but after considerable tinkering, Carthoris was able to propel his wounded flier at low speed, a rate which could not approach the rapid gait of the thoat, whose eight long, powerful legs carried it over the ochre vegetation of the dead sea-bottom at terrific speed.

The Prince of Helium chafed and fretted at the slowness of his pursuit, yet he was thankful that the damage was no worse, for now he could at least move more rapidly than on foot.

But even this meagre satisfaction was soon to be denied him, for presently the flier commenced to sag toward the port and by the bow. The damage to the buoyancy tanks had evidently been more grievous than he had at first believed.

All the balance of that long day Carthoris crawled erratically through the still air, the bow of the flier sinking lower and lower, and the list to port becoming more and more alarming, until at last, near dark, he was floating almost bowdown, his harness buckled to a heavy deck ring to keep him from being precipitated to the ground below.

His forward movement was now confined to a slow drifting with the gentle breeze that blew out of the south-east, and when this died down with the setting of the sun, he let the flier sink gently to the mossy carpet beneath.

Far before him loomed the mountains toward which the green man had been fleeing when last he had seen him, and with dogged resolution the son of John Carter, endowed with the indomitable will of his mighty sire, took up the pursuit on foot.

All that night he forged ahead until, with the dawning of a new day, he entered the low foothills that guard the approach to the fastness of the mountains of Torquas.

Rugged, granitic walls towered before him. Nowhere could he discern an opening through the formidable barrier; yet somewhere into this inhospitable world of stone the green warrior had borne the woman of the red man's heart's desire.

Across the yielding moss of the sea-bottom there had been no spoor to follow, for the soft pads of the thoat but pressed down in his swift passage the resilient vegetation which sprang up again behind his fleeting feet, leaving no sign.

But here in the hills, where loose rock occasionally strewed the way; where black loam and wild flowers partially replaced the sombre monotony of the waste places of the lowlands, Carthoris hoped to find some sign that would lead him in the right direction.

Yet, search as he would, the baffling mystery of the trail seemed likely to remain for ever unsolved.

It was drawing toward the day's close once more when the keen eyes of the Heliumite discerned the tawny yellow of a sleek hide moving among the boulders several hundred yards to his left.

Crouching quickly behind a large rock, Carthoris watched the thing before him. It was a huge banth, one of those savage Barsoomian lions that roam the desolate hills of the dying planet.

The creature's nose was close to the ground. It was evident that he was following the spoor of meat by scent.

As Carthoris watched him, a great hope leaped into the man's heart. Here, possibly, might lie the solution to the mystery he had been endeavouring to solve. This hungry carnivore, keen always for the flesh of man, might even now be trailing the two whom Carthoris sought.

Cautiously the youth crept out upon the trail of the man-eater. Along the foot of the perpendicular cliff the creature moved, sniffing at the invisible spoor, and now and then emitting the low moan of the hunting banth.

Carthoris had followed the creature for but a few minutes when it disappeared as suddenly and mysteriously as though dissolved into thin air.

The man leaped to his feet. Not again was he to be cheated as the man had cheated him. He sprang forward at a reckless pace to the spot at which he last had seen the great, skulking brute.

Before him loomed the sheer cliff, its face unbroken by any aperture into which the huge banth might have wormed its great carcass. Beside him was a small, flat boulder, not larger than the deck of a ten-man flier, nor standing to a greater height than twice his own stature.

Perhaps the banth was in hiding behind this? The brute might have discovered the man upon his trail, and even now be lying in wait for his easy prey.

Cautiously, with drawn long-sword, Carthoris crept around the corner of the rock. There was no banth there, but something which surprised him infinitely more than would the presence of twenty banths.

Before him yawned the mouth of a dark cave leading downward into the ground. Through this the banth must have disappeared. Was it his lair? Within its dark and forbidding interior might there not lurk not one but many of the fearsome creatures?

Carthoris did not know, nor, with the thought that had been spurring him onward upon the trail of the creature uppermost in his mind, did he much care; for into this gloomy cavern he was sure the banth had trailed the green man and his captive, and into it he, too, would follow, content to give his life in the service of the woman he loved.

Not an instant did he hesitate, nor yet did he advance rashly; but with ready sword and cautious steps, for the way was dark, he stole on. As he advanced, the obscurity became impenetrable blackness.