When the body of a young girl is found in a Montmartre park, Maigret must team up with a rival investigator to bring her killer to justice.

Maigret and fellow inspector Lognon clash in their investigations into the murder of an unknown young woman in Paris. Maigret endeavors to piece together the story of the girl, and in doing so, uncovers details about her past and her character that lead him to the truth behind her tragic demise.