“Now I have made it my business to find out more about this man. He had a drink at the Three Boars, I learn, and the barmaid there says that he spoke with an American accent and mentioned having just come over from the States. Did it strike you that he had an American accent?”

“Yes, I think he had,” I said, after a minute or two, during which I cast my mind back, “but a very slight one.”

“ Précisément. There is also this which, you will remember, I picked up in the summerhouse?”

He held out to me the little quill. I looked at it curiously. Then a memory of something I had read stirred in me.

Poirot, who had been watching my face, nodded. “Yes, heroin ‘snow.’ Drug-takers carry it like this, and sniff it up the nose.”