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.