Mathilda (Natalie Portman); a young girl from a bad family in the projects comes home one day to see her entire family; including her baby brother; shot in cold blood by a group of hitmen led by a man named Stansfield (Gary Oldman). A chance acquaintance with the next door neighbor; a quiet man Leon (Jean Reno) saves her from falling victim to the hit as well. Once Leon takes her in; he feels responsible for her; and she becomes his companion for the rest of the story. It does not take Mathilda long to figure out that Leon is really a highly trained assassin; and although her child-like excitement at the idea is a source of some friction between them; their bond grows stronger. Mathilda winds up teaching Leon to read; while Leon teaches her a little about his craft. The movie culminates with the final confrontation between Leon and Stansfield.