François Vidocq has been sentenced to eight years' hard labor for a crime he didn't commit. Escaped with the help of his faithful friends Desfossés and Fil de fer, the convict is pursued by his lifelong enemy: the policeman Flambart. Between scams and disguises, Vidocq initially leads an undercover life in 19th-century Paris. Eventually, the two men team up to fight criminals... And Vidocq succumbs to Annette's charms.