Spots 
Analysis differs sharply from simple ingenuity, operating as an extraordinary mental capacity. C. Auguste Dupin demonstrates this power while walking through Paris with his companion, reading his friend's silent thoughts through a chain of observed movements. A chance encounter with a cobblestone layer, a glance at the streetlights, and a mention of an actor allow Dupin to trace an unstated line of thought back to its origin.
Madame L'Espanaye and her daughter Camille are found brutally murdered in a locked fourth-floor room on the Rue Morgue. Neighbors and police who rushed inside heard two voices arguing, but witnesses of different nationalities each insist the shrill voice spoke a language they did not understand. The Prefect of Police arrests a bank clerk named Adolphe Le Bon, despite a total lack of evidence linking him to the impossible scene.
Dupin examines the locked room, discovering a hidden spring on a window and hair that is not human. The extraordinary strength required to thrust Camille up a chimney and the wildly varied foreign voice lead Dupin to identify an escaped Ourang-Outang. By placing an advertisement for a lost animal, Dupin draws a Maltese sailor to his quarters, who confirms how the beast escaped his control and committed the violence.
C. Auguste Dupin solves an impossible double murder in Paris through pure analytical reasoning.