The Grey Cells of Mr. Poirot

Agatha Christie was an English mystery novel and short story writer, and playwright. Her enduring works include 66 detective novels and 14 short story collections, especially those featuring the two recurring characters of Hercule Poirot and Miss Marple. She also wrote the world's longest-running play, "The Mousetrap," a murder mystery, and six romance novels under the name of Mary Westmacott.
Hercule Poirot, a Belgian detective, is one of Christie's most famous long-lived characters who appeared in 33 novels, one play ("Black Coffee"), and more than 50 short stories published starting in 1923 in "The Sketch," a British illustrated weekly journal that ran for 2,989 issues between February 1, 1893 and June 17, 1959.
This book collects all 23 stories published in The Sketch" in 1923. Later on, the stories were published in book form, sometimes under a different title, as part of "Poirot Investigates" (1924) and "Poirot's Early Cases" (1974).