The central character, Auguste Dupin, is idiosyncratic, more than a little egocentric, and somewhat of a recluse.

He is highly observant and an expert at creating chains of reasoning based on his observations. His companion is a somewhat plain man in comparison to Dupin and primarily exists to serve as Dupin's foil, as well as functioning as an auditor for Dupin's explanations and a transmitter of his thoughts.

The heart of the story, as it is to become the heart of practically every detective story since, centers not on the action of the crime but rather on Dupin's explanation of how he solved it. The points about the murders which stump the police—the contradictory reports of neighbors as to the language they heard spoken and the fact that there seems no possible means of entering the room where the murders took place...