Commissioner Jean Belin provides a fascinating history of his experiences as a detective within the French Sûreté Nationale, primarily in the years between the two World Wars. Belin tracked down murderers, forgers, thieves, and secret society plotters, leading to several high-profile arrests. Other difficulties Belin encountered were corrupt politicians and the rising Nazi menace that eventually brought in the Vichy regime. Through it all Belin sought justice through careful and thorough investigations.