C. Auguste Dupin is the central character of three stories written by Edgar Allan Poe in the 1840s and recognized as pioneering works in the Detective Fiction genre, especially influencing Arthur Conan Doyle's Sherlock Holmes and, to an extent Agatha Christie's Hercule Poirot.
- "The Murders in the Rue Morgue" (1841)
- "The Mystery of Marie Rogêt" (1842)
- "The Purloined Letter" (1844)
Set in Paris, the stories are narrated by Dupin's friend and roommate, whose name is never given. Dupin himself is an amateur investigator who belonged to a once wealthy and respected family that fell into disrepair. He now resides with the narrator in Faubourg St. Germain, where they enjoy a quiet and secluded existence. A keenly analytical fellow, capable of extraordinary feats of ''ratiocination'' (once perfectly deducing his companion's exact train of thought), he applies his skills to put himself in the criminal's shoes and bring the solution to the baffled police prefect G.
A list of adaptations can be found here. Audiobook readings of the stories have been performed by the likes of Christopher Lee, Anthony Quayle, Andrew Sachs, Kerry Shale and Bronson Pinchot.
These stories contain examples of:
- Author Tract:
- There's a passage of about a page or so in "The Purloined Letter" in which Dupin explains why mathematicians aren't very good at reasoning. This is tangentially related to the story, but one does wonder if it needed to be explored in such detail.
- There's a long digression in "The Murders in the Rue Morgue" heaping scorn on the idea that chess is a measure of intellect. Instead, the narrator claims, whist and draughts (aka checkers) do a much better job determining the intelligence of the players
- Clueless Mystery: In all the stories, Dupin's solutions depend on clues that aren't revealed to the audience until the summation, if then. In The Murders in the Rue Morgue, for example, the only clue which Dupin and the reader both have is the testimony about "the shrill voice". Everything else that Dupin discovers, the reader has no way of knowing.
- Document MacGuffin: The eponymous purloined letter, which is being used to blackmail an unnamed French female royal (it's usually assumed to be the Queen, but the story never specifically identifies her). Precisely what is so injurious as to be blackmail-worthy is never addressed.
- First-Person Peripheral Narrator: The story is narrated by the nameless Sidekick.
- Friendless Background: Implied by the narrator's own commentary in the stories, which indicate that he and Dupin are one another's only friends.
- Gambler's Fallacy: The narrator expresses a belief in this fallacy in "The Mystery of Marie Rogêt".Nothing, for example, is more difficult than to convince the merely general reader that the fact of sixes having been thrown twice in succession by a player at dice, is sufficient cause for betting the largest odds that sixes will not be thrown in the third attempt. A suggestion to this effect is usually rejected by the intellect at once. It does not appear that the two throws which have been completed, and which lie now absolutely in the Past, can have influence upon the throw which exists only in the Future. The chance for throwing sixes seems to be precisely as it was at any ordinary time—that is to say, subject only to the influence of the various other throws which may be made by the dice. And this is a reflection which appears so exceedingly obvious that attempts to controvert it are received more frequently with a derisive smile than with anything like respectful attention.
- Gentleman Detective:
- Dupin is considered the Trope Maker. He comes from a wealthy family, although at the time of the stories he has been reduced to a more humble lifestyle.
- Poe's own notes about him say the following: Holds the rank of Chevalier (Knight) in the Légion d'honneur. Likes hieroglyphs. Can spell "ratiocination".
- Gratuitous French: In the first story, the occasional french word/phrase is thrown in.
- Great Detective: So much so that Sherlock Holmes was based on him.
- Hidden in Plain Sight: In "The Purloined Letter", a blackmailer's home was searched for an incriminating letter. Even though they searched under every rug, in every drawer, for loose paperwork in every book, and for hollow hidden compartments in the furniture, the searchers never found it because they didn't bother to consider and look closely at a torn and crumpled letter, clearly visible in a card rack hanging on the mantelpiece.
- I Know You Know I Know: In "The Purloined Letter", Dupin explains that this is the reason he can outwit the police and get his man. The police know who stole the document; the thief knows the police know. The difference between Dupin and the police is that Dupin knows the suspect knows the police know, and the police don't know that.
- Inner Monologue Conversation: Probably Trope Maker. Dupin is famously capable of responding to his companion's inner monologue, by deducing from body language what he must have been thinking. In "The Murders in the Rue Morgue", Dupin shows off his general awesomeness by tracking the narrator's train of thought through fifteen minutes of silent walking and several mental topic shifts, and saying exactly the right thing at the end.
- Killer Gorilla: The "murderer" in "The Murders in the Rue Morgue" is, in fact, not a human but an escaped orangutan wielding a razor.
- Luke, I Am Your Father: Certain critics think D, in "The Purloined Letter", is Dupin's father. Others think the two men may be brothers, as indicated by the reference Dupin makes to the ancient Greek twins Atreus and Thyestes. Still others say certain critics are completely nuts.
- The Main Characters Do Everything: In "The Purloined Letter", protagonist Dupin finds the titular item because he's the only person clever enough to try to think like the thief does.
- Middle Name Basis: We never do find out what Dupin's actual first name is.
- No Name Given: Dupin's friend.
- Phone-In Detective: Dupin solves the mystery of Marie Rogêt by reading the newspaper accounts.
- Police Are Useless:
- In the first story, the police failed to make any progress in the case and smart detective Dupin has to save the day.
- In general, Prefect G is frequently made fun of by Dupin and the Narrator for regularly running out of ideas and being forced to turn to Dupin's atypical way of thinking.
- Profiling: How Dupin figures out where the thief of "The Purloined Letter" hid the letter, and how he figures out the nature of the killer in "The Murders in the Rue Morgue".
- Replaced with Replica: In "The Purloined Letter", after locating the letter, Dupin surreptitiously swaps it for a duplicate letter which obviously doesn't contain the incriminating information that would have allowed the villain to use it for blackmail.
- Ripped from the Headlines: The murder of Marie Rogêt was inspired by the contemporary real-life mystery surrounding the death of a woman named Mary Rogers in New York. (Notice that "Marie Rogêt" is a Frenchified version of the name "Mary Rogers".)
- "Shaggy Dog" Story: Although Dupin solves the case of "The Murder of Marie Rogêt", the audience isn't informed of more than Dupin's complex reasoning, aside from a very brief editor's note mentioning that the killer was caught. This is partly because the story is inspired by real events, which themselves were never solved.
- Sherlock Scan: Duping helped establish this trope pre-Holmes.
- Sidekick: The narrator of Dupin's stories.
- Smart People Play Chess: Subverted in "The Murders in the Rue Morgue". The story begins with a discussion on the difference between calculation and analysis (the latter being a "true" indicator of intellect), and uses chess as an example of the former, noting that in chess, the winner is typically whoever can concentrate longer, not whoever is smarter.
- The Watson: The anonymous narrator. Indeed, he probably served as the inspiration for the trope namer.
- Year X: The stories all take place in the year "18—". We do know from "The Purloined Letter" that they take place during a time when France is a monarchy, which pins it down to sometime between 1815 (when the Bourbon dynasty was restored) and 1848 (when the French monarchy was abolished permanently).