Irréversible (French: [iʁevɛʁsibl]) is a 2002 French art thriller film written and directed by Gaspar Noé. Starring Monica Bellucci, Vincent Cassel, and Albert Dupontel, the plot depicts the events of a tragic night in Paris as two men attempt to avenge the brutal rape and beating of the woman they love. The film is made up of a title sequence followed by 14 segments made to look like long takes. Each of these segments is either a continuous shot or a series of shots digitally composited to resemble a continuous shot. The story is told in reverse order.

Theatrically released in France, the United Kingdom and the United States, Irréversible competed for the Palme d'Or at the 2002 Cannes Film Festival and won the Bronze Horse at the Stockholm International Film Festival. Critical reception was mixed, with praise towards the performances and Noé's direction, but criticism towards its graphic portrayal of violence and rape. American film critic Roger Ebert called Irréversible "a movie so violent and cruel that most people will find it unwatchable," and around 200 people walked out of the screening at Cannes. A version of the film told in chronological order, Irreversible: Straight Cut (French: Irréversible – Inversion intégrale), was released in 2023.

"Time destroys everything" (French: "Le temps détruit tout").

"Time reveals everything" (French: "Le temps révèle tout").

Alex and Marcus, a young couple, wake up together and discuss their relationship, as well as an upcoming party, while in the nude. Marcus voices concern about Alex's ex Pierre also being invited because he "stole his girl", to which Alex responds that he did not steal anything, because she is not an object and it was all her decision. Alex reveals she had a dream of herself standing in a red tunnel that breaks in two. The two talk about a potential pregnancy and Marcus expresses hope in one before Alex takes a pregnancy test, the result of which is never shown, but she seems particularly pleased with.

On a public train, Pierre, Alex's ex who is also invited to the party, constantly bickers with Alex over his inability to satisfy her during their relationship, while Marcus shows no interest in their squabble. Alex explains to Pierre that he always focused too much on her, and a sexual partner can feel and is aroused by their partner's pleasure. At the party, Marcus gets drunk and takes cocaine, much to Alex's disapproval. She leaves the party, asking Pierre to look after Marcus. Alex descends into a red pedestrian underpass on her way back to the train when she notices a transgender prostitute getting attacked by a man. He immediately turns his attention to Alex, anally raping her before savagely beating her into unconsciousness.

After Marcus and Pierre discover Alex being taken away by paramedics, they encounter street criminals Mourad and Layde, who offer to help them find the culprit. They use an ID left at the scene by the prostitute to locate her. Marcus verbally assaults Concha, the prostitute, and threatens to cut her face open in order to gather that the rapist's name is Le Ténia ("the tapeworm") and that he frequents a gay BDSM club called Rectum. The men are chased off by other prostitutes; Marcus and Pierre jump into a taxi cab and speed off into the night. When the cab driver doesn't know where Rectum is, Marcus attacks the driver, stealing his vehicle. The two end up finding Rectum, with Pierre reluctantly following behind Marcus. Leading the charge, Marcus proceeds to get into a fight with a man he suspects of being Le Ténia, who ends up breaking his arm before attempting to rape him. Pierre comes to his rescue and beats the man to death with a nearby fire extinguisher as the man's companion, the actual rapist, watches in amusement. Marcus is carried out of Rectum on a stretcher while Pierre is arrested by police.

Meanwhile, in a nearby small apartment, a man named the Butcher tells a friend that he was arrested for raping his daughter before dismissing the commotion going on outside.