* CompleteMonster: [[Literature/TheABCMurders ABC]] and [[Literature/{{Curtain}} Mr. X]]. See those pages for details.
* CriticalResearchFailure: In ''Death in the Clouds'', it is said that a blowpipe is about a foot long, when in actuality it is six feet long, a mistake that Christie admitted. [[AuthorAvatar Ariadne Oliver]] also makes a reference to the research failure in a novel of hers in ''Mrs. [=McGinty's=] Dead''.
* FunnyAneurysmMoment: The short story "The Kidnapped Prime Minister", set in 1919 and written in 1925, is about Poirot having to find the titular kidnapped Prime Minister before the Versailles negotiations start, because if he is not present then the treaty might be 'too lenient'. Of course in hindsight it's generally thought now that the harshness of the Versailles treaty played a major role in the rise of UsefulNotes/AdolfHitler.
* TheProblemWithLicensedGames: To a point. Metacritic has given the games based on the series mediocre reviews: ''Literature/MurderOnTheOrientExpress'' was given a score of [[http://www.metacritic.com/game/pc/agatha-christie-murder-on-the-orient-express 60 out of 100]] (though the only saving grace is having David Suchet of the ''Series/{{Poirot}}'' TV series voice the titular character in spite of the fact that the protagonist you control is female); ''Literature/EvilUnderTheSun'' was given scores of [[http://www.metacritic.com/game/pc/agatha-christie-evil-under-the-sun 66 for the PC version]] and [[http://www.metacritic.com/game/wii/agatha-christie-evil-under-the-sun 46 for the Wii version]]; and ''Literature/TheABCMurders'' was given [[http://www.metacritic.com/game/ds/agatha-christie-the-abc-murders a score of 53]].
* RecycledScript: Some of Poirot's adventures are so good, other characters copy them.
* ValuesDissonance: "The Augean Stables" sees Poirot go to great lengths to bury and discredit accusations of embezzlement by a former Prime Minister... which happen to be true. This obstruction of justice, which involves destroying a man's career, is considered right and proper in order to defend the late Prime Minister's reputation, prevent his party from suffering a great loss of face, and prevent a politician from another party from becoming the new Prime Minister (as he is considered to be most unsuitable for the position). Nowadays Poirot would be the villain in the story. Although to be fair, Poirot says he would not lift a finger were the politician still alive, and that DontShootTheMessage is the only reason he's getting involved at all.
* ViewersInMourning: Poirot is the only fictional character to have received an obituary in the ''New York Times''. (At least one paper did an obit for [[NewJediOrder Chewbacca]]).
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