C. Auguste Dupin - The Trilogy

"The Murders in the Rue Morgue" is a short story by Edgar Allan Poe published in "Graham's Magazine" in 1841. It has been recognized as the first modern detective story; Poe referred to it as one of his "tales of ratiocination". Two works that share some similarities predate Poe's stories, including "Das Fräulein von Scuderi" (1819) by E. T. A. Hoffmann and "Zadig" (1747) by Voltaire. C. Auguste Dupin is a man in Paris who solves the mystery of the brutal murder of two women. Numerous witnesses heard a suspect, though no one agrees on what language was spoken. At the murder scene, Dupin finds a hair that does not appear to be human. As the first fictional detective, Poe's Dupin displays many traits which became literary conventions in subsequent fictional detectives, including Sherlock Holmes and Hercule Poirot. Many later characters, for example, follow Poe's model of the brilliant detective, his personal friend who serves as narrator, and the final revelation being presented before the reasoning that leads up to it. Dupin himself reappears in "The Mystery of Marie Rogêt" and "The Purloined Letter".

"The Mystery of Marie Rogêt", often subtitled "A Sequel to 'The Murders in the Rue Morgue'", is a short story by Edgar Allan Poe written in 1842. This is the first murder mystery based on the details of a real crime. It first appeared in "Snowden's Ladies' Companion" in three installments, November and December 1842 and February 1843.

"The Purloined Letter" is a short story by American author Edgar Allan Poe. It is the third of his three detective stories featuring the fictional C. Auguste Dupin, the other two being "The Murders in the Rue Morgue" and "The Mystery of Marie Rogêt". These stories are considered to be important early forerunners of the modern detective story. It first appeared in the literary annual The Gift for 1845 (1844) and was soon reprinted in numerous journals and newspapers.