I explained Poirot's departure and the fact that I proposed to accompany him to Southampton.
"That's all right. Leave the man here. He won't get into mischief. He's suffering from complete exhaustion. Will probably sleep for eight hours on end. I'll have a word with that excellent Mrs. Funnyface of yours, and tell her to keep an eye on him."
And Dr. Ridgeway bustled out with his usual celerity. Poirot hastily completed his packing, with one eye on the clock.
"The time, it marches with a rapidity unbelievable. Come now, Hastings, you cannot say that I have left you with nothing to do. A most sensational problem. The man from the unknown. Who is he? What is he? Ah, sapristi, but I would give two years of my life to have this boat go to-morrow instead of to-day. There is something here very curious—very interesting. But one must have time—time. It may be days—or even months—before he will be able to tell us what he came to tell."
"I'll do my best, Poirot," I assured him. "I'll try to be an efficient substitute."
"Ye-es."
His rejoinder struck me as being a shade doubtful. I picked up the sheet of paper.
"If I were writing a story," I said lightly, "I should weave this in with your latest idiosyncrasy and call it The Mystery of the Big Four." I tapped the pencilled figures as I spoke.
And then I started, for our invalid, roused suddenly from his stupor, sat up in his chair and said clearly and distinctly:
"Li Chang Yen."