MY DEAR LOVE,--My note written last night was short, because I had scarcely anything to say, and I postponed what I had to tell until to-night. Mrs. Holdfast did not detain Fanny long yesterday. She asked but one question, which, if the little girl had not been prepared to answer, would have removed Fanny from the game, and increased the difficulties of our task. In the story Fanny invented for the mystification of Mrs. Holdfast I saw one great danger. Mrs. Holdfast is not playing alone; there is a master mind behind her. Who that master mind is it was necessary for me to discover, and I have made the discovery. I shall not be surprised if, in the letter I shall write to you to-morrow night I am able to tell you something of the very greatest moment. Fanny's danger was this: She had told a clever story; had invented a sister, and had furnished a tolerably fair excuse for forcing herself upon a lady of Mrs. Holdfast's position. But she had spoken of herself and her sister living in lodgings in London. If there is one thing Mrs. Holdfast desires at present to avoid it is the slightest chance of anything coming before the public which would tend to prove that she and Grace who destroyed Sydney Campbell are one and the same person. Perhaps the only person who, in an indirect way, is aware of this fact (that is, to Mrs. Holdfast's knowledge) is Fanny. Here was a risk; and between Fanny's first and second visit to Mrs. Holdfast, the suggestion had in some way arisen that the little girl might have been instructed in her part by an unseen enemy. It was necessary, therefore, to test the truth of Fanny's story, and there was only one point which could be seized upon. In what street in London, in what house, did Fanny and her sister live before the sister ran away? This occurred to my sharp mind before it had been suggested to Mrs. Holdfast, and I determined to manufacture evidence. I enlisted Mrs. Preedy on my side. I bought her a new gown, a cloak, and a hat, and I made her a present of them. Then, having entirely won her heart--she told me that she looked upon me as a daughter--I cautiously imparted to her what I wanted her to do for me. It appeared that nothing was easier. For a few shillings a friend of Mrs. Preedy, living half a mile from Great Porter Square, undertook, in case a lady called to ask there, to give certain answers to certain questions about two lodgers, one called Nelly and the other Dot. The lesson was a simple one, and was easily learned. Armed with the address, Fanny went to Mrs. Holdfast, according to appointment. I may inform you that I am placing fuller reliance than ever upon little Fanny, and that I have related to her a great deal of Grace's life in Oxford, which, in case of need, she can turn to useful account. As I anticipated, Mrs. Holdfast asked Fanny in what house she and her sister lived in London. Without hesitation, Fanny gave the address of Mrs. Preedy's friend, and Mrs.