"'Even as it is easier,'" I muttered thoughtfully, "'to unfasten a barred door from within than from without." What was it of which that strange sentence reminded me? Ha! I had it. Of the night on which we had fled from Master Lindstrom's house, when Mistress Anne had been seized with that odd fit of perverseness, and had almost opened the door looking upon the river in spite of all I could say or do. It was of that the sentence reminded me. "To whom is it addressed?" I asked abruptly. "To Mistress Clarence," my lady answered. "No; inside, I mean." "Oh! to Mistress A---- B----. But that gives us no clew," she added. "It is a disguise. You see they are the two first letters of the alphabet." So they were. And the initial letters of Anne Brandon! I wondered that the Duchess did not see it, that she did not at once turn her suspicions toward the right quarter. But she was, for a woman, singularly truthful and confiding. And she saw nothing. I looked at Master Bertie. He seemed puzzled, discerning, I fancy, how strangely the allusions pointed to Mistress Anne, but not daring at once to draw the inference. She was his wife's kinswoman by marriage--albeit a distant one--and much indebted to her. She had been almost as his own sister. She was young and fair, and to associate treachery and ingratitude such as this with her seemed almost too horrible. Then why was I so clear sighted as to read the riddle? Why was I the first to see the truth? Because I had felt for days a vague and ill-defined distrust of the girl. I had seen more of her odd fits and caprices than had the others. Looking back now I could find a confirmation of my idea in a dozen things which had befallen us. I remembered how ill and stricken she had looked on the day when I had first brought out the letter, and how strangely she had talked to me about it. I remembered Clarence's interview with, not Dymphna,--as I had then thought,--but, as I now guessed, Anne, wearing her cloak. I recalled the manner in which she had used me to persuade Master Bertie to take the Wesel instead of the Santon road; no doubt she had told Clarence to follow in that direction, if by any chance we escaped him on the island. And her despair when she heard in the church porch that I had killed Clarence at the ford! And her utter abandonment to fear--poor guilty thing!--when she thought that all her devices had only led her with us to a dreadful death! These things, in the light in which I now viewed them, were cogent evidences against her. "It must have been written to some one about us!" said the Duchess at length. "To some one in our confidence. 'On our side of the door,' as he calls it." "Yes, that is certain," I said. "And on the wrapper he styles her Mistress Clarence. Now who----"