"You don't seem to grasp quite all that this means," he continued. "For the first time in my life, I have signed a certificate of death for a living person!"

"You have signed the certificate?" I asked.

He nodded.

"The undertaker has it."

The maid entered just then with the tea. I ordered another cup for Rust, and when it had arrived, I made him sit down opposite to me.

"His was exactly the kind of illness," he remarked thoughtfully, "to lead to something of this sort. I am quite sure now, whatever Kauppmann's friend may say, that his disease was not a natural one. He has been suffering from some strange form of poisoning. It is the most interesting case I have ever come in contact with. There were certain symptoms—"

"Rust," I interrupted, "forgive me, but I don't want to hear about symptoms. I want to talk to you as man to man. We are old friends! You must listen carefully to what I have to say."

Rust's good-humored, weather-beaten, little face was almost pitiful.

"You're going to pitch into me, of course," he remarked. "Well, I suppose I deserve it. You may not believe it, but I can assure you that ninety-nine out of every hundred medical men would have signed the certificate in my case."

"I have no doubt of it," I answered. "That is not the matter I want to discuss with you at all. There is something more serious, terribly serious, behind all this. Frankly, if I did not know you so well, Rust, I should offer you the biggest fee you had ever received in your life, to leave the place this morning and be called to—Timbuctoo. As it is," I continued more slowly, "I am going to appeal to you as a sportsman! I am going to take you into my confidence as far as I dare. I want, if I can, to justify a very extraordinary request."