Northcote's eyes narrowed, and his lips set in a singularly unpleasant smile. "It is a private affair," he answered coldly, "and I'm afraid it must remain so. I can assure you, however, that in taking my place you will not be in danger except of assassination. I have committed no crime"--he laughed--"at least, no crime in the excellent eyes of the English law." "That is comforting," I observed, "but, all the same, I should be more inclined to accept if I knew who it was that was so anxious to stick a knife into you." "Unfortunately," he answered, "I don't know myself. If I did"--his face hardened for a moment into a cruel mask. "Well, I think you have a proverb about two being able to play at the same game. I can only tell you that the danger is real and imminent. I have good reason for believing that my own servants are honest, but beyond that I would trust no one." "It seems to me," I said sadly, "that I shall have to stay indoors." Northcote thrust his hand into his pocket, and pulled out a small red leather notebook. "After the first ten days," he said, "you can please yourself. To start with, you would have to carry out certain engagements I have made, which you will find in this book." "And you imagine I could do that successfully?" Northcote nodded. "You have excellent nerves and plenty of common sense. Provided you give your word of honour to carry the part through to the best of your ability, I am perfectly ready to trust you. If you fail"--he shrugged his shoulders--"at least I shall have had my start." A sudden mischievous joy in the promised excitement of the situation came flooding through my heart. With an almost involuntary gesture I thrust my arm across the table. "Very well," I said. "I promise you I'll do my best." He gripped my hand, and for a moment we sat there on either side of the table without speaking a word. Northcote was the first to break the silence. "I envy you your nerve, Mr. Burton," he said coldly. "It's not as good as it was," I replied, with regret. Northcote tore a slip of paper out of his pocket-book and, laying it on the table, began to draw a plan in pencil. I pulled my chair round so that I could see what he was doing. "I'm making you a rough sketch of the inside of the house," he said. "This is the ground floor, and here's the dining-room and the billiard-room. Your study and bedroom are on the first floor, exactly above. They open into each other--like this." He outlined the various rooms neatly and skilfully, writing their names in the centre of each square. "That's plain enough," I said, taking the paper. "What about the servants?" "There are only three of them--two women, and Milford, the butler. I have got rid of all the others during the last two weeks. These three have all been with me since I took the house, and I think you may trust them. Milford you certainly can. I've treated the man well, and he's by way of being rather grateful."