In Agatha Christie’s short story, “The Lost Mine,” Poirot investigates the suspicious disappearance of a Chinese businessman in London. Suspicion is focused on two Englishmen, one of whom has an alibi and another who was in an opium den the night of the disappearance. However, a clear-cut case for Poirot soon becomes murky. This short story originally appeared in the November 21, 1923 issue of The Sketch magazine.