"Nothing has been touched," he said. "I have removed the wires, in case of danger. We have the lady more or less under our thumb." "What was she doing?" Geoffrey asked. "It is an appliance for exhausting air," Tchigorsky explained. "You take a powder and place it on a hot plate. Directly it begins to burn it draws up all the air. The thing has been known in the East for thousands of years. Mrs. May applied electricity to give her greater scope. A plate of the powder was to be heated in the room of everybody in the castle when asleep. "A few minutes and the thing is done. Then the wires are withdrawn and gradually the different rooms fill with air again. The burnt powder leaves no trace. Then you are all found dead in your beds and nobody knows how it is done. The wires are easily drawn back to the battery and the whole thing is destroyed." Geoffrey shuddered. "What a fiend!" CHAPTER XLVI NEARING THE END It was some time before any one spoke. Geoffrey was turning the whole matter over in his mind. He was still puzzled. "I don't understand it," he said. "Of course, I follow all you say, and I see the nature of the plot intended to end us all at one fell swoop. But why do you want to have that woman under the roof?" "Because so long as she is under the roof she is comparatively harmless," Tchigorsky explained. "The princess is hot and vengeful and passionate, but she has her vein of caution and will take no unnecessary risks. She will be bewildered and will not know whether she had been suspected or not. The more cordial to her you are the more suspicious she will be. Of course, she will make up some plausible tale to account for her intrusion, and, of course, you must pretend to believe it. It will be impossible to move her for a day or two, and here I come in." "In what way?" Geoffrey asked. "In the way of having a free hand," Tchigorsky said, with a smile. "The princess will be cut off from her allies, and I shall be able to ransack her private papers for one thing." Geoffrey nodded. He began to see the force of Tchigorsky's clever scheme. And then the cold solitude of the house struck him. For a moment he had forgotten all about the family still on the beach and the agony they were suffering on his account. "I suppose you can do no more to-night?" he asked. "I am not so sure of that," Tchigorsky said dryly. "Meanwhile I can safely rest for an hour or so. I am going to lie hidden in Ralph's bedroom for the present and smoke his tobacco. Do you want anything?" "I should like to relieve the minds of my friends," said Geoffrey. "That of course," Tchigorsky responded. "Go at once. You were picked up by a passing boat--or yacht--that landed you at Manby. You walked back and when you got home to change your clothes you found the place deserted. Don't say anything as to Mrs. May. Your Uncle Ralph will have that story to tell when you return. You are not to know anything about Mrs. May."