The Disappearance of Mr. Davenheim

The Disappearance of Mr. Davenheim is a short story by Agatha Christie, first published in 1923.

The plot begins when a wealthy banker vanishes without a trace after leaving his country house for a short walk to the nearby post office. His hat and letters are never found, and there are no witnesses who can explain what happened in that brief stretch of time.

The case becomes more intriguing when a senior Scotland Yard inspector visits Poirot and jokingly wagers that even he cannot solve such a baffling mystery without leaving his own apartment. Accepting the challenge, Poirot vows to solve the disappearance using only his “little grey cells”, relying on logic, psychology, and details reported by others instead of traditional field investigation.

As the police pursue obvious leads Poirot calmly considers the banker’s background, recent business troubles, and the behavior of those around him. By focusing on what would be most convenient for the missing man himself, Poirot begins to suspect that the mystery is not about what was done to the banker, but about what the banker might have done.

"Poirot and I were expecting our old friend Inspector Japp of Scotland Yard to tea. We were sitting round the tea table awaiting his arrival. Poirot had just finished carefully straightening the cups and saucers which our landlady was in the habit of throwing, rather than placing, on the table. He had also breathed heavily on the metal teapot, and polished it with a silk handkerchief."