“But what does the reference to the letter mean?” I asked. “For my part, I am entirely in the dark about it.” “So am I,” he answered, frankly. “The chief one among the obstacles which I mentioned just now is the obstacle presented by that same ‘letter.’ The late Mrs. Eustace must have been connected with it in some way, or Dexter would never have spoken of it as ‘a dagger in his heart’; Dexter would never have coupled her name with the words which describe the tearing up of the letter and the throwing of it away. I can arrive with some certainty at this result, and I can get no further. I have no more idea than you have of who wrote the letter, or of what was written in it. If we are ever to make that discovery--probably the most important discovery of all--we must dispatch our first inquiries a distance of three thousand miles. In plain English, my dear lady, we must send to America.” This, naturally enough, took me completely by surprise. I waited eagerly to hear why we were to send to America. “It rests with you,” he proceeded, “when you hear what I have to tell you, to say whether you will go to the expense of sending a man to New York, or not. I can find the right man for the purpose; and I estimate the expense (including a telegram)--” “Never mind the expense!” I interposed, losing all patience with the eminently Scotch view of the case which put my purse in the first place of importance. “I don’t care for the expense; I want to know what you have discovered.” He smiled. “She doesn’t care for the expense,” he said to himself, pleasantly. “How like a woman!” I might have retorted, “He thinks of the expense before he thinks of anything else. How like a Scotchman!” As it was, I was too anxious to be witty. I only drummed impatiently with my fingers on the table, and said, “Tell me! tell me!” He took out the fair copy from Benjamin’s note-book which I had sent to him, and showed me these among Dexter’s closing words: “What about the letter? Burn it now. No fire in the grate. No matches in the box. House topsy-turvy. Servants all gone.” “Do you really understand what those words mean?” I asked. “I look back into my own experience,” he answered, “and I understand perfectly what the words mean.” “And can you make me understand them too?”