When Inspector Lognon is gunned down in the line of duty, Chief Inspector Maigret must reconstruct the victim's final, secretive days to identify the assailant. Maigret navigates the professional and personal life of the embittered Lognon, whose recent activities involved monitoring a mysterious woman who has since vanished. The investigation forces Maigret to confront the intersection of high-stakes art forgery and the psychological toll of police work. The narrative follows a linear progression, focusing on the methodical collection of clues within the atmospheric, rain-slicked streets of Paris.

Readers frequently highlight the atmospheric quality of the prose, noting how the author captures the grit and melancholy of Parisian life. Discussion often centers on the contrast between the cynical Lognon and the more observant, empathetic Maigret. Critics often point to the author's ability to maintain tension through character interaction rather than relying on high-octane action sequences. The book is widely regarded as a study in human nature, focusing on the motivations behind crime rather than just the mechanics of the act itself.