Léon: The Professional is a 1994 English-language French thriller film. It was written and directed by Luc Besson. The film stars Jean Reno as the titular mob hitman; Gary Oldman as corrupt and mentally unhinged DEA agent Norman Stansfield; a young Natalie Portman, in her feature film debut, as Mathilda, a 12-year-old girl who is reluctantly taken in by the hitman after her family is murdered; and Danny Aiello as Tony, the mobster who gives the hitman his assignments. The hitman and Mathilda form an unusual relationship, as she becomes his protégée and learns the hitman’s trade.
Leone “Léon” Montana is a hitman living a solitary life in New York City’s Little Italy. His work comes from a mafioso named Tony, who operates from the “Supreme Macaroni Company” restaurant. Léon spends his idle time engaging in calisthenics, nurturing a houseplant that early on he describes as his “best friend”, and watching old Gene Kelly musicals.
One day, Léon sees Mathilda Lando, a twelve-year-old girl who is smoking a cigarette and sporting a black eye. Mathilda lives with her dysfunctional family in an apartment down the hall. Her abusive father and self-absorbed stepmother have not noticed that Mathilda stopped attending class at her school for troubled girls. Mathilda’s father attracts the ire ofcorrupt DEA agents, who have been paying him to stash cocaine in his apartment. After they discover some of the drugs missing, DEA agents storm the building, led by sharply dressed drug addict Norman Stansfield.
During the raid, Stansfield quickly becomes unhinged and murders Mathilda’s entire family one by one, except for Mathilda, who was missing only because she was out shopping. Mathilda returns from her shopping trip as the group cleans up the carnage, and realizes what happened just in time to continue down the hall, where she desperately knocks on her neighbour’s door. A reluctant Léon gives her shelter.
Mathilda discovers that Léon is a “cleaner”, or hitman. She begs him to take care of her and to teach her his skills as a cleaner. She wants to avenge the murder of her four-year-old brother, telling Léon that he was the only one of her family she loved. Léon shows her how to use guns, including a scoped rifle. In return, she runs his errands, cleans his apartment, and teaches him how to read. Several times Mathilda tells Léon “I love you”, but he offers no response.
Then one day after Mathilda has learned how to shoot, she fills a bag with guns from Léon’s collection and sets out to kill Stansfield. She bluffs her way into the DEA office by posing as a delivery girl, only to be ambushed by Stansfield in a bathroom. Mathilda learns from Stansfield and one of his men that Léon has killed one of the corrupt DEA agents in Chinatown that morning. Léon, after discovering her plan in a note left for him, rescues Mathilda, shooting two more of Stansfield’s men in the process.
Stansfield, now enraged that Léon has killed more of his men, goes to find Tony, then beats him to find out where Léon is.
When Mathilda returns home from grocery shopping, an NYPD ESU team sent by Stansfield takes her hostage and attempts to infiltrate Léon’s apartment. Léon ambushes the ESU team and grabs Mathilda. Back in his apartment, Léon creates a quick escape for Mathilda by smashing a hole in an air shaft. He reassures her and tells her that he loves her and that she has given him “a taste for life”, moments before the police come for him. In the chaos that follows, Léon sneaks out of the apartment building disguised as a wounded ESU officer. He goes unnoticed save for Stansfield, who recognizes him and follows him downstairs, sneaks up behind him, and shoots him in the back. As Léon falls, he places an object in Stansfield’s hands that he says is “from Mathilda”, and dies. Opening his hands to see the object, Stansfield discovers that it is the pin from a grenade. He then opens Léon’s vest to find a cluster of active grenades, which detonate moments later, the huge explosion killing him instantly.
Mathilda heads to Tony’s place as Léon had instructed her before he died. Tony reveals to Mathilda that Léon instructed him to give his money to her if anything happened to him. He offers to hold the money and provide it to her on an allowance basis, on account of her youth. Mathilda asks Tony to give her a job, insisting that she can “clean” like Léon. Tony angrily shouts he “ain’t got no work for a 12-year-old kid.” He tells Mathilda she should “forget all this craziness” and return to school. Mathilda meets with the headmistress, who readmits her but insists she stop telling lies. Mathilda confesses the true reason for her absence. Mathilda then walks into a field near the school with Léon’s houseplant in hand. She digs a hole and plants it, as she had told Léon he should, to give it roots.