For 10 points name this story that, as a follow up to Murders in the Rue Morgue, is the third story to feature C. Auguste Dupin.
The protagonist of this work argues that mathematicians make mistakes akin to most people rejecting pagan stories by citing Bryant's Mythology. Halfway through this story, a tale is told about Abernethy, who consults an imaginary person for medical advice. Its protagonist writes on a piece of paper a cryptic sentence about Prosper Crebillon's Atree et Thyeste, and wears thick green spectacles in order to disguise his quick search. The beginning of this work sees one man describe how he has repeatedly search through a hotel and the legs of various pieces furniture looking for the title object, which belongs to a royal personage. Eventually, the protagonist is able to retrieve from Minister D the titular document and return it for fifty thousand francs. For 10 points name this story that, as a follow up to Murders in the Rue Morgue, is the third story to feature C. Auguste Dupin.
The protagonist of this work argues that mathematicians make mistakes akin to most people rejecting pagan stories by citing Bryant's Mythology.
"The Purloined Letter"