Two mismatched cops team up to investigate the murder of a business mogul's wife.
Paris, 1830. In the heart of the town, Vidocq, a famous detective, disappears as he fights the Alchemist, an assassin that he has been pursuing for a few months. His young biographer, Etienne Boisset, decides to avenge Vidocq's death and takes the investigation on...
Doctor Knock is a former thug who has become a doctor and arrives in the small village of Saint-Maurice to make his fortune according to a particular method. It will make the villagers believe that they are not as healthy as they might think. It is thus that he will find in each one an imaginary symptom, or not, and thus will be able to exercise his profession lucratively. Under his seductive looks and after gaining the confidence of the village, Knock is on the verge of achieving his ends. But his past catches up with him and an old acquaintance disrupts the doctor's plans.
