"I had no time to consider the probability or otherwise of this question. Certain sounds from the other room drew me back at once to the side of M. Platzoff. Signs of returning consciousness were visible. I propped him up with the pillows, and sprinkled water on his face, and chafed his hands. Slowly he came back to life. 'Better--better--all right now,' were his first words; then turning his lack-lustre eyes on me, 'Who are you?' he said. 'Ah, I remember--Jasmin,' he continued before I could reply. Then all of a sudden a frightened look came into his face, and he began to fumble nervously in the pocket of his velvet dressing-gown. 'What have you lost, sir? Is it anything I can find for you?' I asked. 'No, no,' he replied excitedly; 'only my key--only my key. Ah! here it is,' he cried a moment later, as he brought into view from one of his pockets a curiously-shaped key, the like of which I had never seen before. With a great sigh of relief he sank back on his pillows. "'Go and wake up Wrigley, and tell him to give you some cognac,' he said next minute. 'A little brandy is all I need at present.' "I left the room to carry out his request, and was not away more than five minutes. As I handed him the cognac I glanced stealthily at the mirror. The opening in the library wall was no longer visible. The mirror reflected an unbroken array of shelves closely packed with books. M. Platzoff had evidently felt himself strong enough to get out of bed and fasten the secret door during my absence. "He drank a little of the brandy and then told me that I might go back to bed. I proffered to sit up in the next room during the remainder of the night. But he would not hear of it: only, he said, he would have the lights kept burning. I had got my hand on the door when he called me back. 'Look here, Jasmin,' he said. 'It is my particular wish that not to any one shall you say a single word respecting what has happened to-night. Not even to Cleon must you mention it. Obey me in this, and you will find that I shall not forget you. Disobey me, and I shall be sure to hear of it. What say you?' "Of course I promised all he asked, and he seemed tolerably easy in his mind when I left him. I satisfied Cleon's curiosity with a passable excuse, and then went back to bed. "M. Platzoff is lying later than usual this morning. Consequently I have an hour or two to myself, which I now employ in finishing this report. Write to me as soon as possible after receipt of it, and let me have your opinion as to what my next step ought to be. Cleon will be able to resume his duties in two or three days, and when that event takes place I shall be relegated to my old position, and shall have little or no personal communication with M. Platzoff. "Your affectionate Son, "J.M." CHAPTER XIII. ROOM NUMBER FOUR IN THE CORRIDOR. It has now become requisite to return to Captain Ducie, whose proceedings have been neglected for some time past.