Instead of an interminable drop to the bottom of an abyss, Farrell landed in less than a second, and feet foremost, on slippery flags. He noted that the air was not as stagnant as one would expect in an oubliette.

"Plenty of circulation ... just put me in temporary storage until they get around to organizing a committee to finish me with pomp and ceremony," he muttered as he struck a match.

Farrell saw that the walls of the dungeon were curved. He strode toward the center, and by the light of a second match saw a massive column of masonry which rose from floor to ceiling. He remembered the pool he had seen on the floor above, and concluded that the pillar before him was a hollow shaft which led to some subterranean spring in the heart of the knoll on which Bayonne was built.

"All in one piece, unhurt, and no enemy in sight—yet!" he reflected as he skirted the column.

Among the inevitable rubbish with which the dungeon would be littered Farrell hoped to find some fragment of rock, scrap of wood, anything, in fact, which would give him the means of meeting the enemy with more than bare hands. But before he could strike his next match, Farrell saw a glow of light at a considerable distance to his right. It faintly outlined a low archway, and suggested possible escape from the dungeon into which he had been dropped by Hassan. That same light, however, betokened the immediate presence of the enemy, and perhaps an armed sentry. Farrell therefore crept on in darkness until he was well out of line with the source of light, then left the column and progressed toward the wall.

His knee came into contact with something hard and metallic. He struck a match, and saw that he had found a chain, one end of which was attached to a massive leg-iron, and the other secured to an eye-bolt sunk into the wall. The shank of the eye-bolt was badly corroded where it entered the masonry. A few minutes of wrenching and tugging sufficed to separate the chain from its anchorage. The result was a crude flail which in a strong hand could shatter whatever skull it struck.

Farrell was armed again, and his spirits rose accordingly.

He retraced his course and crept down the passageway toward the light. As he halted in the shelter of a jamb he saw that the vault ahead of him was illuminated by a glowing brazier; and the scene gave him a foretaste of what his own fate might be.

The black, oily form of a muscular negro crouched beside the brazier. The bellows in his hands wheezed from his vigorous efforts to fan the charcoal fire to a white heat. Tongs or other long-handled implements projected from the incandescent mass.

Limned in harsh highlight and black shadows Farrell saw two white-robed Ismailians whose predatory, Semitic features were stern from the contemplation of their task. Both were armed with simitars and pistols. The object of their scrutiny was a man who sat crouched by a pilaster. Farrell could distinguish no features beyond the aquiline curve of his nose, and the black, spade-shaped beard. The hands, clasped about the knees, were fettered at the wrists.

"God!" muttered Farrell as the red glow became a dazzling whiteness. "That lad sitting there looks for all the world like an innocent bystander. Either that party isn't for him, or he has more guts than any ten men I've ever seen.... I've not been here long enough for that to be my reception committee...."

Farrell appraised the situation, and gaged the distance between his lurking-place and the group at the brazier.

"Too far! They'd get wise before I got within striking distance ... now if this piece of chain were only a solid bar so that I could slug, swat, and parry instead of having to use it like a whip ... now what?"

The taller of the Ismailians glanced up, and with a gesture indicated the ceiling. Farrell could not distinguish his words, but it was evident that he had addressed the negro, who set aside his bellows, picked up a length of thin rope, and rose.

Then Farrell understood. They were going to slip the cord through a ring in the low ceiling, lash the prisoner's ankles, and suspend him so that the white-hot irons could be applied without interference from the victim's agonized writhing.

"Missed my chance!" growled Farrell. "They were all off guard, and I could have cold-calked them! Too late, now."

The Ismailian on the right addressed the prisoner; but the other was looking in Farrell's direction, though not directly at his lurking-place. The negro was shifting the implements that projected from the bed of coals.

Then Farrell tested the idea that came to him an instant after his expression of disgust. He reached into his pocket and found a large silver coin the size of an American dollar. He sent it spinning across the vault. It struck the opposite wall and tinkled to the floor.

As the Ismailian at the left of the group started, caught the gleam of silver, and stooped to pick it up, Farrell, whirling his flail, leaped from cover and charged.

The startled cry of the crouching negro was simultaneous with the impact of the swinging fetter against the skull of the stooping enemy. The massive circlet of iron crunched home as the other white-robed enemy whirled from confronting his prisoner and drew a pistol. Farrell knew that he could not lash out with a second blow of his flail. He ducked as the pistol flashed, gripped the Ismailian's wrist as the pistol cracked again, and back-heeled him. They crashed to the flags, Farrell striving to keep the pistol out of effective action and to disable his enemy before the giant negro recovered his wits enough to overwhelm him.

With a fierce wrench, Farrell disarmed the Ismailian and sent the pistol flying against the wall. And then the negro took a hand. They pounded and crushed Farrell as they sought to drive home with knife-thrusts which he evaded in his struggles to drive in with boot or knee. He finally, thrashing about, seized the shackle end of his flail; and as the Ismailian's knife darted in, Farrell jabbed the ponderous iron to the enemy's jaw with a crushing blow.

Then the negro crushed Farrell to the paving. Farrell's struggles were futile; the cumulative effect of previous combats was telling. In another moment his breath would be completely cut off by those relentless black hands....

Then an agonized yell, and the stench of burning hair and flesh. The pressure relaxed as a shower of white-hot charcoal rained from the frenzied enemy and seared Farrell's hands and face. But the respite, though brief, sufficed. Farrell's boot laid the enemy out flat.

Then he rose, recovered the pistol that lay against the wall, and turned to confront the fettered prisoner.

"Fortunately," said the prisoner, "I was able to reach the tongs and flip that brazier into the party."

The mutual benefactors regarded each other a moment.

"Monsieur," began Farrell, recognizing the prisoner as a Frenchman, "I am more interested in getting out of here than exchanging compliments. Judging from the preparations I interrupted, you were in for a pleasant evening, morning, or whatever it may be."

"Unfortunately," came the reply, "these fetters are rivetted, and none of the tools they brought——"

"I'll tend to that," assured Farrell. He turned and set the brazier right side up, then with the tongs collected the still glowing charcoal, and fanned it once more to a white heat. "Get your chains hot enough," he explained, "and we can break them by hand."

"Magnifique!" Then, regarding Farrell more intently, "But I don't recognize you as any of the Brethren who might be kindly disposed—though those fellows lying on the floor prove the case."

"I'm not quite what I seem," admitted Farrell as he arranged the chains so that they could get the full heat of the brazier. Then, staring for an instant at the prisoner and at the device engraved on the emerald set in his massive ring, Farrell hazarded a guess that seemed warranted by the absence of the host who had issued the invitations to the soirée at the château.

"Are you by any chance the Marquis——"

"C'est moi! Des Islots, and everlastingly at your service!" The saturnine features brightened for a moment.

As Farrell pumped the bellows, he wondered at the fortuitous meeting.

"Did Hassan put you in here?"

"No. Shirkuh, his second in command, arranged this. Hassan is too busy to bother with details——"

"He had plenty of time for me," countered Farrell.

"Hmmm ... then Shirkuh must be occupied with some important mission," began the Marquis.

"The late Shirkuh," corrected Farrell with a grim smile.

"Sacré bleu!" ejaculated the Marquis. "Did you——"

"I have the honor—and pleasure," admitted Farrell.

"Thank God! He was my evil genius. Years ago, in Syria, I joined the Ismailians as an Associate. I was a student of the occult, you understand. Their aim at the time was harmless enough: the overthrow of Islam, and the pursuit of mystic speculations. For centuries the order has had no secular significance, you comprehend.

"I advanced to the rank of Initiate, then returned to France and organized a thaumaturgical society which was to carry on with the researches I had made in Syria, and in High Asia. And this was all well until fellow Ismailians came to Bayonne, one by one, and ended by converting the thaumaturgical society into a chapter of Ismailians.

"Shirkuh was the chief of these, a prior. And then they reverted to the tactics of the Twelfth Century. To augment the hasheeshin that they sent over, they recruited cutthroats from the underworld of Paris. Various actresses and women of the demi-monde were led to believe that they had been admitted as Associates, and were set to work as spies.

"There is a plot even now under way which, if successful, will upset the French colonial empire and end in a jihad that will stir up the entire Moslem world.

"Another chapter has been organized in Lyons, with a prior in charge; and Hassan is Grand Prior of France, acknowledging only the supreme chief in Damascus.

"At all events, when I saw the political aspect of the Ismailians who had gained their foothold through my thaumaturgical society, I protested to Shirkuh—and here I am. Hot irons and other pleasant devices were to make my end most colorful."

"Where," wondered Farrell, "does La Dorada fit into the picture?"

"Eh? La Dorada? Why, a sort of chief female spy—she is friendly with many high officers and civilian dignitaries, you comprehend. She is——"

"Was," interrupted Farrell. "Three assassins finished her."

"Diable!" exclaimed the Marquis. He was amazed rather than grieved.

"You take it calmly, for a lover," remarked Farrell.

"Lover?" The Marquis laughed sourly. "I, her lover? Camouflage, to account for her presence down here, and along the Riviera. As to her being assassinated, that is easily explained: her mission must have been completed. So she was killed to insure her continued secrecy, and also to warn her dupes that they would follow suit if they relented or weakened in the course dictated by Hassan. And that move makes it all the more conclusive that France is due for an explosion."

The confusion was being untangled. Farrell wondered at Antoinette Delatour's connection, and the source of the dreams that had haunted her; but the chains that bound the Marquis were white-hot and ready to break, so that conversation would have to wait.

"All right, heave!" directed Farrell.

The chains parted.

They stripped the bodies of the white-robed Ismailians, and armed themselves with their simitars and pistols, as well as taking the extra cartridges that studded one of the belts. And the keys that had admitted the executioners completed the equipment. As the hot ends of the chain cooled, the Marquis bound them to his limbs so that they would not clank.

"I wonder," said Farrell as they turned toward the iron-bound door, "if those lads are completely out."

"Cordieu! But I am absent-minded!" growled the Marquis. He drew the simitar at his side.

As Farrell unlocked the door, he heard the sword-strokes that assured beyond all doubt that three more had entered al jannat.

"Wait a minute!" exclaimed Farrell as the door closed behind them. "We may run into a detachment on the way down here to finish me. Do you know of any other way except the passage used by your executioners?"

The Marquis reflected for a moment as he wiped and sheathed his blade.

"I do," he replied. "But we'd stand a good chance of getting lost and perishing in a labyrinth. This network is older than the Roman occupation. We have reclaimed but a fraction of it. It is the sanctuary of some awful, prehistoric past. And there were living proofs...." The Marquis shuddered at the recollection of what he had seen. "We killed most of them. But—as for me, I prefer to face men like ourselves! Anyway, if Shirkuh is dead, Hassan will be busy until another Prior is appointed. Shirkuh was an adept who studied in Tibet. A necromancer——"

Farrell shivered, and as they advanced up the passageway, told the Marquis what he had seen at the château.

"Canaille!" muttered the Marquis. "The night I was imprisoned! Just like him. And as you suspect, enough assassins in the crowd to spread the rumor of his miracle.

"Our best chance," he resumed, "is to go to the vault where you saw Hassan unveiled, thence to the assembly hall of the assassins. Then cut our way out—if we can! The chances are slender——"

"How about passing by the Garden?" wondered Farrell.

"Out of our way," protested the Marquis. "But why?"

"A ... friend," replied Farrell. "Mademoiselle Delatour——"

"What?" exclaimed the Marquis with a start. "Dieu de Dieu! How——"

Then he controlled his agitation, beckoned for silence.

They emerged from the darkness and turned into an upward-sloping branch passage illuminated by torches thrust into sconces on the wall. Ahead of them they heard the measured tread of a sentry walking his post.

"Hang back," whispered the Marquis as he fingered the hilt of the broad-bladed knife that kept his simitar company. "I know the passwords. And he may not know I'm a prisoner—but be ready for trouble if he does!"

The sentry challenged the Marquis. There was an exchange of sign and countersign. Then as the sentry saluted, the Marquis' right hand flashed to the right; his body jerked forward. As Farrell advanced, he saw the sentry collapse and sprawl across the tiles in a grotesque heap.

"So far, so good," muttered the Marquis as he wiped his blade, and led the way.

A barred door yielded to the Marquis' touch on a concealed lever. They continued on their upward march. They halted finally before a door whose panels were of heavy and elaborately carved woodwork.

"Diable!" growled the Marquis as he tried the door. "Barred from the other side. The release this side does not help us."

The mutter of drums and the plucked strings of a sitar were plainly audible.

"Better wait until the place is vacant," whispered the Marquis. "And in the meanwhile, let's cut a loophole and see what's happening."

They drew their knives and set to work.

Peering through the loophole, Farrell could see the arched niche from whose foot he had been precipitated into the dungeon below. Hassan was again, or perhaps still, at his post. He was veiled, but there was no mistaking the posture and the expression of the eyes.

Sitting cross-legged along the curved wall of the vault were a score of Ismailians in white ceremonial robes. They wore white turbans, scarlet slippers, and belts of the same color: and all were armed with the richly adorned simitars suitable to a formal assembly.

A group of musicians squatted on the floor, along the coping of the circular pool, whose dark water reflected the spectral glow that pervaded the vault. The wind instruments joined the music with a demoniac sobbing and moaning, and a brazen gong clanged.

Four litter-bearers emerged from an entrance. Attendants followed them, bearing tripods of bronze. Farrell shuddered at the similarity of that scene to the horrible beauty of the resurrection of La Dorada. Then he noted that the figure on the litter was that of a man.

As the shroud was lifted, he recognized Shirkuh of the clan of Shadi. The Prior of the Ismailians was to receive the final homage of his subordinates. The pipes wailed mournfully in honor of that desecrator of the dead. Farrell sighed with relief, and glanced at the Marquis.

He peered once more through the loophole.

"Good God!" he gasped in dismay.

Four more litter-bearers were filing into the vault, and after them came attendants with tripods. The tiny feet and the feminine curves that the shroud revealed unmistakably betokened a woman's body.

Farrell's cheeks whitened beneath their stain as he caught the glint of red-gold hair.

An attendant stripped the brocaded shroud from the body.

Antoinette Delatour, sleeping—or dead.

With an inarticulate growl of rage, Farrell gathered himself to charge the door with his shoulder. But the hand of the Marquis gripping his arm restrained him.

"Wait!" whispered the Marquis. "It is hopeless, now. But later—stand fast. I will tell you—you see, I am acquainted——"

Farrell stared somberly at his companion. He saw that the Marquis' face was white and that his eyes flamed with wrath. The hand on Farrell's arm trembled.

"All right," he conceded. He wondered at the Marquis' incoherence and agitation in excess of what he would expect of a right-minded gentleman. He gained assurance from the Marquis' apparent knowledge of what was to be; but with it came the dread of some new peak of horror.

"Great God!" muttered Farrell, remembering once more the necromantic ritual at the château. "Is she——" Then, in a flare of rage and grief, "I'm going through!"

"Restrain yourself!" commanded the Marquis. "I know."

Farrell shook his head, and turned to the loophole.

The attendants and the litter-bearers were filing out of the vault.

The Grand Prior, Hassan, rose from his cushions.

"Brethren and servants of the Seventh Imam," he began, "your Prior, the learned Shirkuh, has crossed the Border. He who could raise the dead can not resurrect himself. But we, inshallah, can send a courier to lead him back to us."

As his upraised hand dropped to his side, a monstrous peal of bronze echoed and reverberated through the vault. The assembled Ismailians stirred, and corrected their posture, so that their feet and hands were placed with ritual precision. Even their features assumed a oneness of expression: an intent, solemn stare. The silence became absolute. The musicians sat motionless, awaiting the signal to sound off.

The Grand Prior nodded.

The single-stringed violins, the moaning pipes and the purring drums wove a harmony that sighed and sobbed like a fallen angel bewailing his lost estate. The great gong pealed with mighty, brazen reverberations. Acolytes filed into the vault, and paced in cadence to the music, and rhythmically swung fuming censers as they passed thrice in procession about the dead, and the exquisite unclad beauty of the living woman. And as the acolytes retreated, Hassan descended from his dais.

He drew on the floor with a piece of chalk a circle several paces in diameter, and within it a pentacle. Each of the five points he marked with cabalistical symbols. Then with a ceremonious gesture he summoned three Initiates from among those who sat waiting beside the dais. Each Initiate took his post at his assigned station; then all four bowed to the fifth vertex and the Presence that was to be summoned.

Hassan intoned a sentence; and the Initiates, beginning at his left, each in turn chanted a line of the invocation. Those without the circle solemnly pronounced a fifth sonorous phrase.

"For the vacant corner," whispered the Marquis to Farrell. "They are representing the One they are calling to occupy the fifth angle."

And thus they continued their prodigious utterances, four verses riming in succession, with the surge and thunder of the unrimed, antiphonal response from without. Each time the circle was completed, the riming syllable changed; and from the Arabic with which they had started, they shifted to Himyaric, and then to obscure, antique tongues whose sound was an elemental roar of deep gutturals. Then finally came a primal, bestial murmuring and muttering, a chirping and clucking of the tongues that were spoken by those who wandered through the Void before the first man walked the earth. And recurring through the entire progression was a portentous name that is seldom pronounced above a whisper.

The very features of the Initiates changed as they pronounced those rustling, shivering syllables. They were achieving a unity with that which crept and crawled and loathsomely slunk through chaos and reviled the unborn stars, and mocked the light that was to be....

Farrell, staring now with a dread that obliterated every other emotion, saw that a Presence was materializing at the fifth vertex. A vibrant glow like the luminous vapor of a mercury arc was momentarily becoming more dense and substantial. Lambent flames played about the brows of the Initiates in the pentacle. A terrific tension pervaded the vault. The bluish glow became deeper, and was shot with flashes of crimson and yellowish green. Each drawn face was now a ghastly slate-gray: the Presence at the fifth vertex was drawing the living essence from the swaying, gesturing bodies of Hassan and his trio of Initiates.

The Presence took human form: a lordly, satanic visage and a magnificently muscled body that quivered and throbbed to the droning chant. Then, rich and clear as a god calling across the wastes of space, the Presence began declaiming:

"Al Asfarani! Al Asfarani! Al Asfarani! I come from the realm of fire to command you! I have come out of the depths! Harken! Harken! Harken! Al Asfarani! Golden One! Step forth from your body and walk into the darkness among those whose bread is dust! Walk among the lonely dead and seek Shirkuh! Call him by his name and take him by the hand! Guide him from the shadows and into the morning!"

The unconscious woman shuddered at the sound of that mighty voice. She made a despairing gesture as if to resist the command that came from the fifth vertex. Then she relaxed.

The Presence continued his prodigious chant. Even the brazen reverberation of the gongs was drowned by his awful utterance.

A thin streamer, like the thread of smoke rising from an almost-quenched altar flame, rose from Antoinette Delatour's half-parted lips.

"Cordieu!" shouted the Marquis in Farrell's ear. "They're doing it!"

His gestures rather than his voice stirred Farrell to action. They retreated, then charged crashing against the door. It resisted the shock. Farrell drew his simitar and hacked at the tropical hardwood. A carven panel splintered.

"Good God! Look!" he yelled in despair.

The Presence was now towering toward the ceiling. It was bending over like a monstrous serpent in human form, arching and writhing, reaching as though over some invisible wall, making passes and gestures over the silver-white body of Antoinette.

The Initiates in the pentacle were paper-white. They swayed to the cadence of that great voice whose concussion was now making the very vault tremble.

The train of smoke-like vapor that emerged from Antoinette's lips was becoming more dense, and hovered over her body like a veil.

"Quick!" shouted the Marquis, as they frantically hacked the stout wood. "Hold them, while I exorcise the Presence!"

The door was reinforced with iron rods that bound it together. Their blades were nicked and saw-toothed from the fierce assault.

"Again!" cried the Marquis as his simitar flashed home.

A chunk of the hardwood tore loose from its severed reinforcement. They shouldered through, torn and cut by the splinters and the ragged ends of the rods they had hacked.

A musician cried out and sprang to his feet. And then one of the Initiates who sat beside the dais saw Farrell and the Marquis as they dashed across the circular vault. He aroused his comrades from their fascinated contemplation of the invocation of which they were now accessories rather than principals. They started as from a deep sleep, stared for an instant, then drew their simitars and charged to meet the intruders, and to protect the left flank of the pentacle, from which the Presence still leaned over the unconscious girl, intoning the mighty commands that would send her across the Border.

Shoulder to shoulder, Farrell and the Marquis met the assault with deliberate, deadly pistol fire. The attack was checked; but the enemy stood fast and firm, protecting the pentacle. And despite the hail of lead they had poured into the ranks of the Ismailians, Farrell and his ally were still outnumbered ten to one.

The musicians were salvaging weapons.

There was not enough time to reload the pistols. The Ismailians had recovered from the shock of their murderous reception, and seeing their advantage, leaped forward, blades ready.

Then a clash of steel, and a red mill of slaughter. The Marquis fought with vengeful desperation. He wove in and out, side-stepping and parrying, shearing and slaying. And Farrell, keeping at his side, carved a gory path into the enemy. He fought with a blind, unreasoning fury, seeking to hack his way through the press and clear a road for the Marquis who could cope with that monstrous Presence that was in thunderous tones chanting the life and vital essence from Antoinette.

The enemy, sensing that the Marquis was the keystone of the arch, concentrated their attack on him; and despite his exquisite swordsmanship, he was being slashed to pieces by a desperation and force that discounted his skill.

He sank once beneath a whirlwind of blades, and recovered under the shelter of Farrell's blade; but he was coughing blood from a deep wound.

And Hassan and his trio had left the pentacle. The Presence, now endowed with the power borrowed from all that the Initiates had conjured from across the Border, was self-sustaining and no longer needed its portion of human vitality.

Hassan, behind the line of the assault, directed his Initiates in the attack.

"Cut him down, O sons of flat-nosed mothers!" he cried, as he saw the Marquis recover and press forward.

But that magnificent last effort burned out. With a cry of mortal rage, the Marquis lashed out with a final, devastating stroke, then collapsed on a heap of slain.

"Finish!" despaired Farrell. He was doomed, and Antoinette also—even though he could cut his way out. An adept was required to exorcise that terrific Presence that was drawing her from her body.

But the enemy, instead of closing in to hew him to pieces, gaped stupidly, then yelled in terror. They were staring at something at his right, and to the rear. He glanced over his shoulder, compelled by the consternation that stopped them where they stood.

Farrell lowered his own point, himself struck with awe. He recalled what the Marquis had said about the denizens of that labyrinth of passages.

A monstrous, amorphous thing had emerged from the circular pool into which Hassan had ordered the dead fedawi to be flung. It was misshapen, and grotesque in its vague semblance to humanity. Its bulbous head had a single, circular eye the size of a saucer. It glittered glassily in the bluish, spectral light. The limbs were shapeless and ponderous, and it lumbered, dripping wet, across the tiles. Its feet fell with a metallic clank, and its breath hissed and wheezed.

A second and similar creature was emerging from the water, even as the first advanced with slow, laborious pace. The hand clutched a short iron bar.

The bar rose in a sweeping arc and crunched down on the skull of an Ismailian, spattering blood and brain in a shower. The second monster clambered over the coping, unlimbered a bludgeon, and with gruesome deliberation picked a victim and struck.

There was a moment of silence unbroken save for the wheezing breath of the creatures from the pit. Then the Ismailians yelled in mortal terror. They forgot Farrell with his dripping blade and bewildered eyes; they forgot the Marquis, who stirred, and strove to lash out once more with his red scimitar; they forgot the golden-haired girl, and the malevolent Presence that, now silent, throbbed and pulsed, an aggregate of quivering, electric-bluish cold fire.

They broke and fled toward the splintered door.

At the height of their panic, Farrell understood. The monsters were men in diving-suits.

The Marquis was down. Farrell could not himself thwart that monster that was drinking Antoinette's vital essence and taking her across the Border beyond recall; but he could slay until he dropped from wounds, or from weariness of slaughter. He hurdled the hedge of fallen Ismailians and with a cry of rage and grief joined his allies to exact vengeance.

A third diver was at that moment emerging from the pool and joining the assault against the frenzied enemy, striking them down with remorseless precision as they struggled to crowd through the splintered panel of the door that had given Farrell admittance.

Farrell, however, was not the only one whose wits had recovered from the terror inspired by the apparitions from the black pool.

"Back and face them, ya mumineen!" shouted Hassan. "They are men like ourselves!"

But his attempt to rally his men was vain. Those who abandoned their efforts to crowd through the jammed door, and circled around to escape by way of the opposite entrance, were blocked by the arrival of a file of fedawi who, knives drawn, had come running from the assembly hall.

The dripping revolvers that the divers drew as they discarded their grappling-irons crackled and flamed, pouring a deadly fire into the new center of action.

Then Farrell conceived the desperate device of capturing Hassan and forcing him to recall the elemental monster that was drinking Antoinette's life. He leaped forward, cutting and slashing his way through the few who interposed.

"We meet in Paradise, ya mumineen!" Hassan shouted, seeing that the day was lost. And before Farrell could seize him, Hassan released the trap-door before the dais and dropped into the vault below.

The last hope was gone. Pursuit through those subterranean mazes would be futile. As Farrell turned from the yawning trap that had allowed the arch-enemy to escape, the rage of slaughter left him. The crackle of pistols died out. He saw that the circular chamber was cleared of all but the dead and wounded Ismailians. The divers, handicapped by their heavy suits, could not carry out an effective pursuit of the survivors of their deadly fire.

Weary and despairing, Farrell nerved himself to confront the diabolical creature that was drawing Antoinette across the border. He turned——

The Marquis des Islots was raising his hacked, bleeding body from a heap of slain. He tottered, swayed, then advanced toward the lambent flame-presence. Farrell stared in fascination as that gory wreck of a man advanced, making ritual gestures with his faltering hands, and muttering in a low voice.

The Presence was shrinking and dimming, and that shimmering exhalation from Antoinette's lips was being retracted. The Marquis sustained himself with will alone. He staggered, sank—Farrell's heart sank with him—he recovered, stepped forward again, still gesticulating and murmuring. The Presence leaned forward to confront him, and menaced him with its remaining energy, seeking to outlive the dying adept.

The Marquis' bleeding, gashed face was drawn and white; his eyes were fixed and staring. He achieved another pass; then he collected himself, paused, and instead of murmuring, thundered a final phrase of command.

The Presence vanished; and the last vestige of grayish, luminous haze disappeared between Antoinette's lips.

Farrell leaped forward in time to catch the Marquis as he collapsed.

The divers, returning from the farther entrance at which the Ismailians had made their last stand, lifted one another's domed helmets. Then, grimy and exultant, Pierre d'Artois and the two members of the Sûreté gathered about Farrell and the Marquis, who was regaining a little of his strength.

"Messieurs," he said, as he gestured toward Antoinette, "she is safe. She will presently awaken. It can not return. Jamais!... It was my fault ... in the beginning ... but this infamy was not my intent.... I loved her, but she rejected me ... persistently. And for revenge ... and to break her spirit ... I administered without her knowledge a compound ... of hypnotic drugs ... so that she and that Syrian girl would each night exchange bodies ... then Hassan took a hand...."

He regarded d'Artois for a moment.

"You, monsieur, doubtless understand——" Then, to Farrell, "But this last infamy ... was not mine—Shirkuh and Hassan—I tried to make ... amends——"

For an instant Farrell regarded the dying man with revulsion. Then he saw the remorse on the drawn, blood-splashed features, and thought of the Marquis' last gallant stand, confronting and exorcising that diabolical presence from beyond the Border.

"Stout fellow," he muttered, as he grasped the Marquis' hand.

"C'est fini," murmured d'Artois a moment later. "Magnificent in his death as he was misguided in his life ... dying on his feet, he had the will to conquer, and make restitution."

Then d'Artois rose and glanced about him.

"Do you know the way out of here?"

"Through that door," directed Farrell. "He told me, before we made our rush."

"Messieurs," suggested d'Artois, "be ready with your pistols, should any of these assassins be lingering. I will take charge of the young lady, and you, my friend, lead the way. Monsieur le Marquis perhaps deserves greater courtesy, but we can not carry his body and take the risk of being caught without weapons drawn and ready."

Farrell led the way. Without much difficulty, he found the passage that opened into the vault where he had lain while regaining his consciousness preliminary to submitting to Hassan's tests. And from there they finally emerged in the heart of the citadel. A few moments later Farrell and d'Artois, carrying Antoinette, met Raoul where he was waiting at the wheel of the Renault.