"My niece!" she exclaimed in surprise. "My poor niece died ten years ago." "Ten years ago!" I gasped. "And is not Miss Cloud your niece?" "I have no niece of that name, sir," she answered. "The name indeed is quite strange to me. There must be some mistake." "But your name is Popejoy," I exclaimed, "and this is Number sixteen, Ellerdale Road?" "Certainly." "Truth to tell, madam," I said, "I have called on you in order to assure myself of a certain very extraordinary fact." "What is it?" "Well, late on a certain night some weeks ago I accompanied Miss Cloud, the lady I am now in search of, to this house. I sat in the cab while she got out, and with my own eyes saw her admitted by your maid. This strikes me as most extraordinary, in lace of your statement that you know nothing of her." The old lady reflected. "What cock-and-bull story did she tell you?" she inquired quickly. "Explain it all to me, then perhaps I can help you." There was something about Mrs Popejoy's manner that I did not like. I could have sworn that she was concealing the truth. "Well," I said, "I met Miss Cloud at a theatre, and she told me that you and another lady had accompanied her; that you had got separated, and being a stranger in London she did not know her way home. Therefore I brought her back, and saw her enter here." The old lady smiled cynically. "My dear sir," she said, "you've been very neatly imposed upon. In the first place, I have no niece; secondly, I've never entered a theatre for years; thirdly, I've never heard of any girl named Cloud; and fourthly, she certainly does not live here." "But with my own eyes I saw her enter your door," I said. "I surely can believe what I have seen!" "It must have been another house," she answered. "There are several in this road similar in appearance to mine." "No. Number sixteen," I said. "I looked it up previously in the Directory and saw your name. There can be no mistake." "Well, sir," snapped the old lady, "I am mistress of this house, and surely I ought to know whether I have a niece or not! What kind of lady was she?" "She was young, fair-haired, blue-eyed, and very good-looking. She had lived in France previously, at Montgeron, near Paris." "Ah!" the old lady cried suddenly. "Why, of course, the hussy! Now I remember. It is quite plain that she duped you." "Tell me," I exclaimed eagerly. "Where is she now?"