Look at this newspaper. It says that there was a murder
You are arrested
Why are the finger marks on her neck so big?
The narrator and Duplin read about the deaths of Madame & L'Espanye and collect information.
My ape was the one who killed them
The police arrest a bank clerk, Adolphe de Bon because they think he was the murderer. Dupin feels like he needs to solve this.
The narrartor and Dupin visit the L'Espanye apartment for more clues
Dupin meets with a french sailor from a maltese ship who has evidence on who the murderer is
Them sailor said that be brought the it to Paris to try to sell it, but it escaped the night of the killings and saw the light on in the open window of the L'Espanaye apartment. The sailor didn't say anything because he didn't want to get blamed.
Lebon gets released, the sailor sells his ape and Dupin is happy he solved the case.