"The Murders in the Rue Morgue" is the first American detective story. It is set on a fictional street in Paris. The story opens with an unnamed narrator discussing the analytic mind just before describing how he meets and becomes roommates with Dupin, a particularly analytical character.
The narrator and Dupin then read newspaper articles of the recent horrific double murder of a woman and her daughter. Accounts include that neighbors, who heard screaming, and two policeman, had broken into the crime scene to find a bloody razor, locks of gray hair, a bag of money, and an opened safe. The mother, who was beaten to death, had been nearly decapitated and the girl was strangled. Her body was found stuffed into the chimney.
As more reports come out, Dupin begins to assess the evidence against the detective reports and decides things don't add up. He becomes more fully involved and goes through an extensive process of analysis of the entire scene.
Eventually, Dupin gets to the bottom of the crime, which turns out to have been done by an Ourang-Outan.