Hollywood, 1927: As silent movie star George Valentin wonders if the arrival of talking pictures will cause him to fade into oblivion, he sparks with Peppy Miller, a young dancer set for a big break.

Léon, the top hit man in New York, has earned a rep as an effective "cleaner". But when his next-door neighbors are wiped out by a loose-cannon DEA agent, he becomes the unwilling custodian of 12-year-old Mathilda. Before long, Mathilda's thoughts turn to revenge, and she considers following in Léon's footsteps.