A little girl named Alexia annoys her father during a drive. As she removes her seatbelt, her father turns around to scold her, causing a car crash. Alexia suffers a skull injury and has a titanium plate fitted into her head. When she gets out of the hospital, she shuns her parents and embraces their car passionately.
Years later, Alexia, now an adult with a large scar on the side of her head, works as a showgirl at a motor show. One night, after a show, a male fan follows Alexia in the showroom's parking lot, declares his love to her, and forcibly kisses her; she then brutally murders him using her large metal hairpin. As she returns to shower, Alexia hears a banging coming from the showroom. She finds the car she modeled with earlier has turned on by itself and enters it naked, has sex with the car, and eventually climaxes.
It is revealed that Alexia is a serial killer who has murdered several men and women in the past few months. She still lives with her parents, who seem unaware of her connection with the crimes and with whom she has a distant relationship.
Eventually, Alexia realizes she has become pregnant after motor oil begins secreting from her vagina. She tries to perform an abortion with her hairpin but fails.
Alexia attends a house party, where she has sex with her coworker Justine. Alexia suddenly murders Justine and proceeds to kill the other guests, except for a woman who manages to escape. Alexia returns home and sets her own house on fire before locking her parents in their bedroom. Now wanted for murder, Alexia alters her appearance to pretend to be Adrien Legrand, a young boy who had disappeared ten years before at age seven, by cutting her hair, taping down her breasts and increasingly pregnant belly, and breaking her own nose. She then goes to the police pretending to be Adrien, where his father, Vincent, accepts Alexia as his missing son and refuses to do a DNA test.
Vincent, a fire captain, takes Alexia to the station where he lives and works and introduces her to his men. The firefighters are puzzled by the mute, androgynous, and apparently traumatized "Adrien", but they refrain from questioning the captain's behavior. Alexia becomes an apprentice at the station, under Vincent's supervision. As Vincent gives more responsibility to his "son" over the other experienced firefighters, one firefighter confronts Vincent about "Adrien's" identity. However, Vincent immediately shuts him down and tells him to never speak of his son.
Vincent tries to preserve his strength by injecting steroids into his aging body, but he finds that he seems to be building an immunity to them. Alexia is increasingly disturbed by his possessiveness and considers escaping from the fire station. However, after Vincent experiences a cardiac arrhythmia from injecting a large dose of steroid, Alexia decides to stay with him.
Vincent's long-estranged ex-wife comes to see her "son", and ends up discovering a now-heavily pregnant Alexia without her body taped down. She nevertheless keeps the secret for herself, not wishing to interfere with her ex-husband's delusion, and begs Alexia to take care of him. Vincent at one point acknowledges his delusion, telling Alexia that "whoever you are, you are my son." When he inadvertently uncovers her breasts, he is clearly shocked but continues caring for her.
At a party at the fire station, the firefighters urge "Adrien" to dance to the music. Alexia breaks out her showgirl choreography, leaving everyone confused. Vincent, disappointed, walks out of the crowd. After the party, Alexia has sex with a firetruck.
Alexia's body gradually breaks down, as the skin of her stomach tears to reveal new metal plates. As her pregnancy finally comes to term, Alexia reveals her real name to Vincent, briefly attempting to seduce him and then begging for his help. Vincent helps Alexia give birth, the titanium side of her skull splitting open on her final push, killing her. Vincent, in tears, holds the baby, whose body appears with patches of titanium, and tells it repeatedly, "I'm here."
just lol wtf
