At the height of Napoleon’s reign, François Vidocq, the only man to have escaped from France's toughest prisons, is a legend amongst the inhabitants of Paris's seediest zones. Left for dead after his latest spectacular escape, the ex-con is lying low as a modest cloth merchant. When his past catches up with him, he is framed by former cellmates for a murder he didn’t commit. To prove his innocence and his good faith, he makes a deal with the police: in exchange for his freedom, he will hunt down all the thieves and murderers on the streets of Paris. Despite exceptional results, he provokes the hostility of his police colleagues and the fury of underworld, which has put a price on his head.