When the brilliant but unorthodox scientist Dr. Victor Frankenstein rejects the artificial man that he has created, the Creature escapes and later swears revenge.

A series of vicious, murderous attacks on three wealthy farms in Picardy hit the national headlines and the elite Brigade Criminelle at the Quay Des Orfevres is called upon to lend its expertise in tracking down the brutal gang responsible for the slaughter. However, Inspector Maigret is resolute in investigating the murder of an obscure anonymous Parisian, an investigation that ultimately solves both crimes.