The Mysterious Affair at Styles is a detective novel by Agatha Christie - the first to feature Hercule Poirot, who went on to become her most famous character and one of the best-known literary characters of 20th-century fiction. It also was the introduction of Captain Arthur Hastings, who was Poirot's hapless sidekick in 9 subsequent books, acting as Christie's version of Dr. Watson, sidekick to Sherlock Holmes.

Written in 1920 and set during World War I, Styles includes many of the classic elements of British murder mysteries. Told in the first person by Hastings, it is set in a large, isolated country manor; includes a half-dozen suspects, most of whom are hiding certain facts about themselves; has maps of the house, the murder scene and a drawing of a fragment of a will; and a number of red herrings and surprise plot twists.

• Project Gutenberg e-text of The Mysterious Affair at Styles (http://www.gutenberg.net/etext/863) (without the illustrations)

fr:La Mystérieuse Affaire de Styles pl:Tajemnicza historia w Styles