"Why not? My dear doctor, seeing that both he and his father have been guests at our house what could we do? We were unable to prove that Pierre was concerned in it, and supposing he turned out to be innocent? What would the Duvals think of us? The father would probably challenge me to fight him, and in any case we should have made them our enemies for life. Put yourself for a moment in Pierre's position. Suppose someone accused you of first setting fire to his house when you were his guest at the time, and then of poisoning a fellow guest who had never done you any harm, by means of some fearful drug, and it turned out afterwards that you were quite innocent, what would you think of him? That is absolutely the case with Pierre." "Not so fast, doctor," said Paul, "I can prove that he is the person who did it. For God's sake do not pose as a miserable sentimentalist." "What!" they all exclaimed with looks of horror on their faces, "do you really mean that Pierre did the dastardly act?" "Certainly. Do you remember, Dr. Roux, when you called on me this afternoon and asked me to help you to draw up your report as you were uncertain whether Delapine was dead or not?" "I do, perfectly." "Well, you recollect that I searched in my text-books to find some drug which would cause a person to lapse into a state of apparent death for a long period, and failing to discover it, I suddenly thought of something, and climbed up a ladder and took a bottle from the top shelf, and to my horror and amazement discovered it to be half empty?" "I do, and what's more you seemed to have lost your senses for a moment, you were so agitated," said Roux. "Now, I suddenly remembered that two or three weeks ago, Pierre, whom I have not seen for two or more years, unexpectedly called and cross-questioned me as to the action of certain secret poisons which science has been unable to detect, and I showed him a Japanese poison which had recently arrived from Tokio. I took the bottle down and showed it to him, and I then replaced it on the shelf. The liquid was a thick, highly refractive dichromic liquid, which had a very unusual appearance something like quinine only much more highly refractive, besides being far heavier. When we left the room we waited in the passage of the house for a cab, when suddenly Pierre asked for the loan of the key of the room as he had forgotten his cigarette case. Not suspecting anything, I gave it to him, and waited there until he returned. To the best of my recollection, no one except my servant has ever had access to the room since, and when I discovered the bottle half empty to-day I knew it must have been Pierre who had opened it." "Yes," said Riche, "and I remember at the séance last week I noticed Pierre quietly slip out of the room and disappear. Well, less than half an hour afterwards we all noticed the smoke of the fire."