“It doesn’t signify,” the man replied. “You’ll do as well.”

On this, I opened the envelope and read the note, which was quite brief, and, at first sight, in no way remarkable.

“Dear Sir,” it ran, “Would you kindly come and see a friend of mine who is staying with me? The bearer of this will give you further particulars and convey you to the house. Yours truly, H. Weiss.”

There was no address on the paper and no date, and the writer was unknown to me.

“This note,” I said, “refers to some further particulars. What are they?”