“Not by Thelma!” I protested.

“No, she has been your fellow victim.”

“But the motive of it all?” I asked in dismay. “What is your opinion, doctor?”

“The same that I formed when you first told me of your offer of help—that you’ve been a silly idiot, Yelverton. Didn’t I point out at the time the risks you were running?”

“Yes, you did,” I replied, “but I still intend—at all hazards—to get to the bottom of the affair.”

Feng hesitated, and then, looking me straight in the face, said very seriously—

“If you take my advice you will drop the whole affair.”

“Why?” I asked, in surprise.

“Because those men who lived at Half Moon Street and their friends are evidently a very queer lot. In any case you ought to cease visiting Mrs. Audley.”

I paused, recollecting that strange warning I had received, of which I had not told him.