SPOILER ALERT: the following article contains massive spoilers, including the ending. If you have not yet seen the movie, proceed at your own risk, or better, come back to this article later!
The mysterious Catherine Tramell (Sharon Stone), a beautiful crime novelist, becomes a suspect when she is linked to the brutal death of a rock star. Investigated by homicide detective Nick Curran (Michael Douglas), Catherine seduces him into an intense relationship. Meanwhile, the murder case becomes increasingly complicated when more seemingly connected deaths occur and Nick’s psychologist and lover, Beth Garner (Jeanne Tripplehorn), appears to be another suspect.
SPOILERS AHEAD
Basic Instinct Plot Summary and Synopsis
In San Francisco, homicide detective Nick Curran investigates the murder of retired rock star Johnny Boz, who has been stabbed to death with an ice pick during sex with a mysterious blonde woman.
Nick’s only suspect is Boz’s bisexual girlfriend, crime novelist Catherine Tramell, who has written a novel that mirrors the crime. It is concluded that either Catherine is the murderer or someone is attempting to frame her. Catherine is uncooperative and taunting during the investigation, smoking and exposing herself during her interrogation.
She passes a lie detector test and is released. Nick discovers Catherine has a history of befriending murderers, including her girlfriend Roxy, who impulsively killed her two younger brothers when she was sixteen years of age, and Hazel Dobkins, who killed her husband and children for no apparent reason.
Nick, who accidentally shot two tourists while high on cocaine during an undercover assignment, attends counseling sessions with police psychologist Dr. Beth Garner, with whom he has an on-and-off affair.
Nick discovers that Catherine is basing the protagonist of her latest book on him, wherein his character is murdered after falling for the wrong woman. Nick suspects that Catherine has bribed Lt. Marty Nielsen of Internal Affairs for information from Nick’s psychiatric file and that Beth had previously given it to Nielsen after he threatened to recommend Nick’s termination.
Nick assaults Nielsen in his office, and later becomes a prime suspect when Nielsen is killed. Nick suspects Catherine, and when his behavior deteriorates, he is put on leave.
Nick and Catherine begin a torrid affair with the air of a cat-and-mouse game. Nick arrives at a club and witnesses Catherine doing cocaine with Roxy and another man.
Nick and Catherine dance and make out, and are later observed by Roxy, having violent sex in Catherine’s bed. Catherine ties Nick to the headboard with a white silk scarf, just as Boz was tied by the mystery blonde, but does not kill him.
Roxy, jealous of Nick, attempts to run him over with Catherine’s car, but dies when the car crashes. Catherine grieves over Roxy’s death and tells Nick about a previous lesbian encounter at college that went awry. She claims that the girl became obsessed with her, causing Nick to believe that Catherine may not have killed Boz. Nick identifies the girl as Beth, who acknowledges the encounter, but she claims it was Catherine who became obsessed.
Additionally, Nick discovers that a college professor of Beth and Catherine’s was also killed with an ice pick in an unsolved homicide, and that the events inspired one of Catherine’s early novels.
Nick comes across the final pages of Catherine’s book in which the fictional detective finds his partner’s body in an elevator. Catherine then breaks off their affair, causing Nick to become upset and suspicious.
Nick later meets his partner Gus Moran, who has arranged to meet with Catherine’s college roommate at an office building, hoping to reveal what really went on between Catherine and Beth. As Nick waits in the car, Gus is stabbed to death with an ice pick in the elevator. Recalling the last pages of Catherine’s book, Nick runs into the building, only to find Gus’ body in a manner similar to the scene described.
Beth unexpectedly arrives and explains that she received a message to meet Gus. Nick suspects Beth has murdered Gus and, believing that she is reaching for a gun, shoots her, but discovers that Beth was only fiddling with an ornament on her key chain.
Evidence collected at the scene and in Beth’s apartment implicates her as the killer of Boz, Nielsen, Moran, and her own husband, along with collections of photos and newspaper clippings of Catherine that imply an obsession with her.
Nick is left confused and dejected. He returns to his apartment where Catherine meets him.
She explains her reluctance to commit to him and the two have sex.
Basic Instinct Ending
As they discuss their future, an ice pick is revealed to be under the bed.
Source: Wikipedia (CC BY-SA 3.0).