She intended to secure my silence regarding the tragedy. Was it because that she herself was the actual assassin? I remembered that while I had reclined upon the silken couch in that house of mystery this startling suspicion had crossed my mind. Was that same cool, sympathetic palm that had twice soothed my brow the hand of a murderess? "But there has been a terrible crime--a double crime committed," I protested. "Surely, the police should know!" "No; all knowledge must be kept from them," she answered decisively. "I wish you to understand me perfectly from the outset. I have sought you here in order to rescue you from this place, because you have unwittingly fallen the victim of a most dastardly plot. You are blind, defenceless, helpless, therefore all who have not hearts of stone must have compassion upon you. Yet if I rescue you, and allow you to go forth again into the world, you may, if you make a statement to the police, be the means of bringing upon me a catastrophe, dire and complete." Every word of hers showed that guilt was upon her. Had I not heard the swish of her skirts as she crept from the room after striking down that unknown man so swiftly and silently that he died without a word? "And if I promise to remain mute?" "If you promise," she said, "I will accept it only on one further condition." "And what's that?" "One which I know you will have some hesitation in accepting; yet, like the first, it is absolutely imperative." Her voice showed traces of extreme anxiety, and the slim hand upon my arm trembled. She was young, I knew, but was she beautiful? I felt instinctively that she was, and conjured up within myself a vision of a refined face, perfect in its tragic beauty, like that of Van Dyck's Madonna that I had seen in the Pitti Palace at Florence in those well-remembered days when I looked upon the world, and it had given me such pleasure. "Your words are very puzzling," I said gravely. "Tell me what it is that you would have me do." "It is not difficult," she answered, "yet the curious character of my request will, I feel, cause you to hold back with a natural caution. It will sound strange; nevertheless, here, before I put the suggestion before you, I give you my word of honour, as a woman who fears her God, that no undue advantage shall be taken of your promise." "Well, explain what you mean."