Twice the vicious demon thrust it through his clothing, and now two crimson stains of blood on his shirt front followed the withdrawal of the weapon. "See! see!" screamed Cervera, triumphantly, with her terrible face upturned to his gaze. "You're beginning to bleed! Did you know that the sight of blood affects me as it does a leopard? I thirst for more--if that of one I hate! When next I strike you, I shall strike deeper!" That she fully intended to murder him, Nick now, had not a doubt. The homicidal madness was in her eyes, in her every feature, her every motion, and it rang in every word that fell from her bloodless lips. Yet the inflexible nerve of the detective did not for a moment desert him. "Send the blade home at once, if you like," he said, with a scornful frown. "Not yet--not yet!" she cried, shrilly. "There'll be time for that." "Time and to spare," sneered Nick. "I first wish to torture you, as you've tortured me!" "Go ahead, then." "Once more! Are you ready?" "Let it come." Again she drew back the glittering blade, only to mock him with several pretended thrusts, hoping thus to create and prolong an agony of fear and suspense. A more viciously cruel and vindictive creature never drew the breath of life. She laughed again, and slowly pressed the weapon closer--and then, with a sudden startled cry, she drew back and leaped to her feet. A noise like that of a mighty cannonade seemed to shake even the solid walls of this buried chamber. It was the crash of thunder in the heavens overhead. It was Cervera's first intimation of the terrible tempest that had been gathering outside. At first she thought the sound was that of revolvers, and she darted to the door and listened, pressing her ear to the wall. The instant her back was turned, Nick made a desperate attempt to free himself, straining cords and muscles under the determined effort. It proved vain, however. The ropes held him as if made of twisted steel. Yet in his brief but desperate struggle his right arm came in contact with an object in the side pocket of his sack coat. The object was a box nearly filled with parlor matches--one of the most dangerous and treacherous creations of man's inventive genius. Like a sudden revelation, or a bolt out of the blue, there leaped up in Nick's mind a possible way of escape. He thought of Cervera's garments, of the fluffy lace skirts beneath her gown, to which a single flash of fire would instantly prove fatal. The resort to such means seemed horrible--yet Nick well knew it was the one and only resource left him. He glanced sharply at Cervera. She was still listening at the door, with her evil face a picture of intense suspense.