It was vastly annoying, for I appeared to have been on the very verge of finding out something about my unknown and apparently strenuous past. I couldn't question her further without breaking my promise to Northcote--indeed, my conscience pricked me with having already failed to live up to the strict interpretation of my pledge. "Well," I said, with a shrug of my shoulders, "we will leave it at that. Please consider yourself at liberty to leave the house when you choose." I put my hand in my pocket and felt the pistol. "By the way," I added, taking it out and holding it towards her, "since you've given me back my latch-key, the least I can do is to restore you your property." She accepted it with an air of bewilderment. "Of course you have some more cartridges," I went on, "but I will trust to your honour--" "Honour!" she broke out. "You talk to me of honour! _You!_" The inference was so obvious that I could hardly pretend to miss it. "Why not?" I demanded. "I've already told you I am perfectly innocent of the crimes you credit me with." I stooped forward and picked up the key from the sofa. "Perhaps you can tell me," I added, "whether there are any more of these useful articles wandering about London. If so, I think I shall go to the expense of a new lock." She shook her head, still staring at me in a kind of puzzled wonder. "I do not know," she said. "It makes no difference. Whether you are innocent or guilty, there is no power that can save you." This was distinctly cheerful! "Perhaps you're right," I said. "But at all events I shall see what the ironmonger can do in the morning. He may at least delay matters." Going to the door, I opened it cautiously, and listened for a moment to see if any of my household were afoot. "The coast seems clear," I said. "I'll come down to the hall and let you out." She made a motion as if to protest, and then changed her mind. "Very well," she said wearily. With an inward prayer that no inopportune domestic would put in an appearance on the scene, I led the way cautiously down the big staircase. It was a strange experience, but by this time I was becoming case-hardened to strange experiences. Anyway, we reached the hall without misadventure, and, pulling back the latch of the front door as quietly as possible, I opened it sufficiently wide to allow my visitor to pass through. As soon as she was outside, I followed her, closing the door behind me. "I'll just stroll along behind you until you pick up a cab," I said carelessly. In the lamplight I saw a flash of terror leap into her eyes. "No, no," she whispered. "You must go back at once, It is not safe." "I quite agree with you," I said. "It's horribly unsafe for a girl to be walking about London alone at this time of night. That's exactly why I propose to find you a cab."