Starring Monica Bellucci, Vincent Cassel, 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.

American film critic Roger Ebert called Irréversible "a movie so violent and cruel that most people will find it unwatchable".

[7] A version of the film told in chronological order, Irreversible: Straight Cut (French: Irréversible – Inversion intégrale), was released in 2020.

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.

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.

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.

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

[9] Gaspar Noé first found financing for the new title after he pitched the story to be told in reverse, in order to capitalize on the popularity of Christopher Nolan's film Memento (2000).

[20] During the first thirty minutes of its running time, the film uses an extremely low-frequency sound of 27 Hz to create a state of nausea and anxiety in the audience, as it is not immediately perceptible to the spectator, but enough to evoke a physical response.

"[23] This technique, called Sensurround, involves the intentional use of a sub-audible sound to enhance the spectator's experience of a movie, in this case, deliberately making them uncomfortable (although this would only be experienced in a cinema setting as most home speakers would not emit such low frequencies).

[29] Newsweek's David Ansen stated that "If outraged viewers (mostly women) at the Cannes Film Festival are any indication, this will be the most walked-out-of movie of 2003."

"[31] Noé's depiction of gay criminal Le Tenia raping the female lead, Alex, remains the film's most controversial image.

[32] Irréversible has been associated with a series of films defined as the cinéma du corps ("cinema of the body"), which according to Palmer[33] includes: an attenuated use of narrative, assaulting and often illegible cinematography, confrontational subject material, and a pervasive sense of social nihilism or despair.