—"The Adventure of the Naval Treaty"
Conan Doyle, in discussing the Holmes canon, consistently acknowledged Edgar Allan Poe as an influence. In his autobiography, Memories and Adventures, Doyle (1924) he writes:
Poe’s masterful detective, M. Dupin, had from boyhood been one of my heroes. But could I bring an addition of my own? I thought of my old teacher Joe Bell…of his eerie trick of spotting details. If he were a detective, he would surely reduce this fascinating but unorganized business to something nearer an exact science.
This acknowledgement was, for Conan Doyle, affording respect and leveling a tender criticism, going so far as to have Holmes acknowledge Poe’s own detective, Dupin, if only with a quintessentially Holmesian air of dismissal, perhaps mimicking the opinion of the author. As Laura Synder commented in a 2004 article that “Conan Doyle criticized his predecessor Edgar Allan Poe for giving his creation – Inspector Dupin – only the ‘illusion’ of scientific method [and]…believed that he had succeeded where Poe had failed” in describing the methods of detection. Poe’s influence can be felt many of the early stories, including the “Speckled Band,” “The Resident Patient,” and “The Naval Treaty,” which shares many similarities with Poe’s “Purloined Letter.” Both stories revolve around a document thought stolen is found to be “hidden in plain sight” by a perceptive detective. In fact, these similarities between the stories are so intertwined that, idiosyncratically, “The Purloined Letter” was adapted (or, in a way, “adopted” into the canon) in a 1979 episode of a Sherlock Holmes and Doctor Watson television series, directed by Val Guest.
Poe’s story, originally published in a 1844 Christmas annual and collected with other Poe tales the following year, extends the detective genre beyond the confines of the murder mystery established by the two previous Dupin stories, “The Murders in the Rue Morgue” (1841) and “The Mystery of Marie Rogêt” (1842). “The Purloined Letter” takes the tale of detection into the realm of espionage and the machinations of government and the aristocracy. This type of intrigue was instrumental in broadening the genre, one of Conan Doyle’s prime motivations in the creation of Holmes, and Holmes’s espionage-related stories, like “The Naval Treaty,” (e.g., “The Second Stain”, “The Bruce-Partington Plans” and “His Last Bow”) are among the most unique stories of the canon.