His 1989 film "The Killer" is a cult classic of Hong Kong action cinema, featuring John Woo's dynamic style as a filmmaker and highlighting Chow Yun-Fat's charisma as its protagonist. Woo has now revisited the film for a 21st-century audience, shifting the action to Paris and putting Nathalie Emmanuel in the leading role, a femme fatale with a strong sense of remorse. We caught up with cast at the film's Paris premiere, where Omar Sy told us more about playing the good cop and doing his own stunts.