Basic Instinct - Plot

Plot

When rock star Johnny Boz (Bill Cable) is viciously stabbed to death with an ice pick during sex by a mysterious blonde woman, homicide detective Nick Curran (Michael Douglas) is sent to investigate. The only suspect is Catherine Tramell (Sharon Stone), a crime novelist who was the last person to be seen with Boz on the night he died. Nick and his partner, Gus Moran (George Dzundza), visit her Pacific Heights mansion, but they find only Catherine's lesbian lover, Roxy (Leilani Sarelle), who sends them to Catherine's Stinson Beach house. When they ask Catherine about her relationship with Boz, she shows little emotion at hearing he is dead. Nick and Gus, along with their superiors, discover that Catherine has written a novel about a former rock star who was killed in the same way as Boz (stabbed in bed with an ice pick, hands tied together with a silk scarf). During questioning by detectives, including Nick, at police headquarters, Catherine engages in provocative behavior, refuses to extinguish her cigarette, and re-crosses her legs — her short skirt revealing that she is not wearing underwear.

Nick, who accidentally shot two tourists while high on cocaine, attends counseling sessions with police psychologist Dr. Beth Garner (Jeanne Tripplehorn), with whom he has had an affair. After the interrogation, Nick goes to a bar with co-workers and is taunted by Lieutenant Marty Nilsen (Daniel von Bargen), an internal affairs investigator bent on making life difficult for Nick. When Beth arrives, Nick leaves with her, and has aggressive sex with her in his apartment. Nick learns that Catherine has a troubled history: Her parents were killed in a boating accident when she was an adolescent, leaving her a fortune; one of her college counselors, Noah Goldstein, was stabbed in his sleep with an ice pick when Catherine was attending UC Berkeley, and her former fiancé, boxer Manny Vasquez, was killed in the ring during a prize fight in Atlantic City. He also discovers that Catherine makes a habit of befriending murderers, including Hazel Dobkins, a woman who stabbed her husband and children for no apparent reason.

During a visit to her house, Catherine taunts Nick with information that should be confidential. As a police psychologist, Beth is the only person with access to that information. When Nick confronts Beth, she admits that she handed his file to Nilsen, who threatened to discharge Nick if he could not evaluate him directly. An enraged Nick storms into Nilsen's office, assaults him, and accuses him of having sold Nick's file to Catherine. Nilsen then suspends Nick, who goes home and spends the evening drinking. Beth visits him, but after a heated argument, he throws her out. Later that night, Nilsen is found dead in his car, shot once in the head with a .38 caliber revolver. Because of their recent altercation, Nick is the prime suspect.

A torrid affair between Nick and Catherine begins with the air of a cat-and-mouse game. Catherine explains that she will base her next novel's character — a cop falling for the wrong woman only to be killed by her — on Nick, while at the same time he declares his love for her and his unchanged intention to nail her for Boz's murder.

A jealous Roxy tries to run Nick over with Catherine's car, but after a car chase she is killed in a crash. Her death reveals that she too has a murderous past — she killed her two brothers with a razor when she was a teenager (because juvenile arrests are sealed until the individual's death, this record did not turn up earlier). After Roxy's death, Catherine seems genuinely saddened, and Nick begins to doubt her guilt. Catherine later reveals that a previous lesbian encounter at college went awry when the girl, Lisa Hoberman, became obsessed with her. Nick identifies the girl as Beth Garner, who acknowledges the encounter but claims it was Catherine who became obsessed. It is also discovered that Beth's husband was killed in an unsolved drive-by shooting, shot with a .38 caliber revolver.

Nick visits Catherine's house. Before Catherine comes into the room he sees on a printer the final pages of Catherine's new detective book. He quickly reads a few lines, in which the fictional detective finds his partner lying dead with his legs protruding from the doors of an elevator. Catherine comes in and explains that she has finished her book, and coldly ends the affair. Upset, Nick meets Gus, who has arranged to meet with Catherine's college roommate at a hotel to find out what really went on between Catherine and Beth. As Nick waits in the car, Gus enters the hotel elevator. As he exits the elevator a hooded figure jumps out and stabs him multiple times in the neck with an ice pick. Nick figures out there is trouble brewing and runs into the building, but he arrives too late to save Gus and finds him lying dead with his legs protruding from the doors of the elevator. Hearing the floor creak, Nick grabs Gus' gun and turns to find Beth standing in the hallway, explaining she received a message to meet Gus there. However, Nick suspects that she murdered Gus, and as Beth moves her hand in her pocket, he shoots her. With her final breath, Beth tells Nick that she loved him. A dejected Nick checks her pocket, only to find her keys. The police arrive, and in a staircase discover a blond wig, an SFPD raincoat, and an ice pick, the weapon used to murder Gus, concluding that Beth ditched the items when she heard Nick coming up. A search of Beth's apartment turns up the evidence needed to brand her as the killer of Boz, Gus, Nilsen, and presumably her own husband—the matching revolver, Catherine's novels, and photos chronicling the writer's life. At police headquarters, all the other detectives quickly piece together the story and conclude that Beth was the killer. Nick sits on his desk, confused and dejected, knowing based on Catherine's foreknowledge of the manner of Gus' death that she must actually have been the killer, and that she must have set Beth up.

Nick returns to his apartment where he is met by Catherine, knowing she's the killer. She explains her reluctance to commit to him, but then the two make love. Afterward, the conversation turns toward their possible future as a couple. Nick looks wary of her, knowing that Catherine must be the killer. While talking, Nick turns his back on Catherine as she slowly reaches for something underneath the bed. He suggests their future will comprise sex and children. Catherine says she hates children and Nick then suggests their future will then just involve sex. At this, Catherine stops reaching for something under the bed, and she throws her arms around Nick, convincing him, and the two resume making love as the camera slowly pans down to show what she was reaching for under the bed: an ice pick. It implies that Catherine is the killer, and she also planned to kill Nick.