Paris. 1830. When the infamous detective Vidocq disappears in the middle of a busy city, nobody can explain the abduction. His archenemy, the Alchemist, the assassin Vidocq has been tracking, is the prime suspect. However, as the police continue to come up empty handed, Vidocq's assistant Etienne his biographer, takes the case into his own hands and delves into the underworld of Paris to findthe missing detective.