"Yes, yes. I see you know all about it. One of the wires runs under the door into the room where Mrs. May is engaged." "And where she will be engaged for some time," said Ralph. "Move that book ladder and look over the fanlight." There were books on high shelves in the corridor, and a light librarian's ladder close at hand. Geoffrey propped this against the door and looked in through the open fanlight. All the bed-room doors had fanlights at Ravenspur. The lantern inside was on the dressing-table and, standing on a chair by a fireplace, was Mrs. May. She had pinned the thin wire to the wall cunningly, and had turned the end of it into a plate that stood on the mantel shelf. From a flask she poured a little white powder into the plate. This done she seemed to be satisfied. Geoffrey whipped the ladder away and the woman emerged from the room. Once more she went along the corridor with firm, resolute step, and the air of one who knows what she is doing and has a definite object in view. From one bed-room to another she went, leaving a wire in each until every room occupied by one of the Ravenspur family had been visited. Geoffrey's room was the last. When she had finished here she took up a pair of scissors and tapped the wire. Outside the door Geoffrey and Ralph could hear the noise distinctly. Ralph's jaws came together with a click. "The key is outside your room door," he whispered. "Turn it." Geoffrey wondered, but he hastened to comply. The key turned with an ease and silence that testified to the fact of its having been carefully oiled. "What does it all mean?" Geoffrey whispered. "She is going to test her machinery," said Ralph with a chuckle. "And she is going one step farther to her own destruction. Listen." Again came the faint tap, and then down from far below the purring jar of electrical apparatus in motion. There was silence inside the room for a moment and then Geoffrey saw the handle turn. It was turned softly at first, then more quickly, and finally it was tugged as an angry child snatches at a toy. Ralph chuckled. The diabolical mirth seemed to come deep from his throat. "She is trying to get out," Geoffrey whispered. "Of course she is," Ralph replied. "But not quite yet." The lock was rattling loudly by this time; there was a half-angry, half-frightened muttering from within. And then there came a long, piercing, wailing scream, as of a woman in the last agony before death. Geoffrey would have started back, but Ralph restrained him. "No, no," he whispered violently. "It is all right; everything is turning out splendidly." "But she is a woman and in deadly peril, uncle." "I know it, lad. Five minutes more and that fiend will be beyond further mischief. She has been trying the effect of her infernal contrivance and will be hoist with her own petard. She is scared to death. She imagines she has fastened herself in and can't get out." "But this is murder," Geoffrey cried.