In a bleak suburb, two young men, Jean-Claude Gérard Depardieu and Pierrot Patrick Dewaere, set out on a brutal spree that fuses petty theft with a dangerous, predatory edge. They harass an older woman, snatch her purse, and after a tense chase they discover there’s little money to show for it. They steal a Citroën DS for a joyride, but when they return it at night, the owner is waiting with a gun. Pierrot is wounded in the groin, and Jean-Claude overpowers the owner, taking the gun, the car, and kidnapping Marie-Ange Miou-Miou along with the man’s escape partner. They pick up Pierrot and drive to a nearby mechanic they know, hoping to swap the DS for another car, while offering the mechanic a chance to rape Marie-Ange.
Leaving with the other car, they force a doctor at gunpoint to treat Pierrot’s superficial wounds and steal the doctor’s money before fleeing. Back at the mechanic’s place, anger bubbles as Marie-Ange is described as passive during the attempted assault. Pierrot fears he may be impotent and suggests sabotaging the DS’s steering to cause an accident on a winding road; they carry out the plan and let Marie-Ange go, but not before obtaining her address.
The trio heads to the country, stealing bicycles and a local car along the way. They pause at a train crossing when police appear, flee their car, and board an almost empty train. A breastfeeding woman is coerced into letting Pierrot nurse from her; the trio share kisses as the moment unfolds, but the woman’s husband arrives at the station, triggering a tense interruption. Pierrot laments that he cannot achieve an erection.
They retreat to a deserted coastal resort, burglarizing a vacation home owned by a family of three, where they discover their daughter Jacqueline. They find her bathing suit and estimate she is around sixteen. Jacqueline Is Isabelle Huppert becomes a focal point of their scheming and predatory gaze.
Back with Marie-Ange, they force her to have sex with both men; this time Pierrot manages an erection. Marie-Ange remains largely passive and mentions that the owner has sold the sabotaged DS. With Marie-Ange’s help, they break into the hair salon where she works; when she protests and screams, they shoot her in the leg and leave her bound to a chair.
When their plan to lure other young women stalls, Jean-Claude proposes seeking an inmate in a women’s prison who is starved for sex. They wait outside a prison and see Jeanne released. Jeanne Jeanne Moreau reluctantly agrees to travel with them after several refusals, and their roadside argument ends with a driver being frightened away by a gun. Jeanne receives money to buy clothes, they head to the beach for an extravagant oyster dinner, and check into a hotel for a night of passion. Yet in sleep, Jeanne suicides by shooting herself in the groin, leaving Jean-Claude and Pierrot to flee with her belongings.
While going through Jeanne’s effects, they learn she has a son named Jacques, Jacques Chailleux who is in jail. After his release weeks later, the trio tell him Jeanne asked them to help him because she is in Portugal. They bring Jacques to a cottage where Marie-Ange waits and urge him to have sex with her. Jacques’s later reactions hint at arousal, and he voices a plan to joint-rob an elderly person, prompting the others to accompany him. They then raid a warden’s house, where Jacques pulls a gun on the warden and shoots him, forcing Jean-Claude and Pierrot to flee with Marie-Ange. They steal another car, and Marie-Ange has sex with each of them while driving, seemingly enjoying it more than before.
News of the murder arrest drives them to press onward, hoping to sever ties with Marie-Ange to avoid implicated guilt. She refuses to be abandoned, and the trio continues stealing cars and hitch-hiking. They encounter a rural family and insist on exchanging their old Citroën Traction Avant for the family’s brand-new DS; the daughter—the Jacqueline they had previously found—amuses herself by trying to intervene with her parents’ consent. When she is struck by her father, she pleads to be allowed to join them, and they take her along, only to realize she is the Jacqueline they had spotted earlier. They smell her and, upon this discovery, drop her by the roadside and press on.