At last the funny side of it struck me and I laughed. “Well, one of us is crazy, I think, and I don’t think it’s I. Now will you tell me what grounds you have for making such a proposal—what possible use I would be to the Secret Service—and how on earth it would help me to join them?” I demanded.

He laughed in his turn. “I admit it sounds absurd,” he said, “but I think I can answer your questions to some extent. Under your pledge of secrecy I can at least tell you that I have the honor to be an operative of the Bureau of Investigation of the Department of Justice. That is one of my reasons for making you this proposal. Secondly, I am not alone in believing that you might be of great service to us at this time, even,” he added, smiling, “if you do give food, shelter and comfort, as we say, to a young gangster!”

I nodded grimly. “Is there anything else that you know about me?”

He laughed. “Yes, quite a lot. In fact, practically everything. I know that you have considerable independent means, that you are, or were, fairly successful as an artist—portrait painter; that your parents are dead; that you are an athlete; that in spite of prohibition you still buy bonded gin and whisky occasionally, by the case, and where you get it; that during your search for your sister you narrowly escaped getting mixed up in that Gerachty murder case; that you were in the room when the man was stabbed, and that you got out by a clever dodge of walking backward, so that when the police entered they thought you were just coming in; that you haven’t by any means given up the hope of finding your sister, and that——” Here I held up my hand and he stopped.

“You certainly have the advantage of me,” I told him. “Now suppose you proceed and tell me why you think the Department will help me in my search?”

He shook his head. “In spite of your pledge, I cannot tell you that, unless and until you decide to join. There is too much in the balance and I have pledges of my own to consider.” He leaned forward and spoke eagerly. “But listen. This is a bona fide offer and I am empowered to make it. You are mixing yourself up, or are trying to, in something far bigger than you have any idea of—something far too big for you to handle alone. Join us! You have got nowhere this way—that I happen to know. Indeed, if you had, almost certainly you would not be here to give me this interview. That much I will tell you. Come with me to-morrow and see the Chief and listen to what he has to say. Perhaps he will make things clearer than I have the right to. But you have nothing to lose and, I believe, everything to gain by joining us. Our Chief is in town for a few days. Will you come?”

I sat taking him in for a moment. “Well,” I answered at last, “I don’t believe you’re crazy anyhow, though the thing sounds absurd enough in all conscience. Moreover, I hate to spare even one day from my search, just because I have got nowhere, as you say. But I think I’ll take a chance and see this chief of yours, whoever he is.”

I broke off short because my visitor had got slowly and silently to his feet and was tiptoeing toward the window, where heavy curtains were drawn half-way back to let in the evening air.

As he passed me, he nodded and motioned me to go on talking, his lips forming the words “Go on!”

“What time do you want me to meet you and where?” I went on at random.