Set in London, the film opens with American best-selling author Catherine Tramell in a speeding car with her companion, Kevin Franks, a famous English football star. Tramell takes the man’s hand and begins masturbating with it, all the while increasing her vehicle’s speed. At the point of orgasm, Tramell veers off the road and crashes into the West India Docks in Canary Wharf. She attempts to save her partner but, as she says while being questioned by the police, “When it came down to it, I guess my life was more important to me than his”.
Tramell is interrogated by Scotland Yard Detective Supt. Roy Washburn, who notes that D-Tubocurarine, a neuromuscular blocking agent used to relax muscles during general anaesthesia, was found in her car and in her companion’s body, and the companion wasn’t breathing at the time of the crash, and that a man named “Dicky Pep” said that he sold Tramell “15 milliliters of DTC last Thursday”. Tramell counters by saying that this Dicky Pep must be lying because “you’ve got him on some other charge and he’s trying to deal his way out, if he even exists”.
Tramell begins therapy sessions with Dr. Michael Glass, who has conducted a court-ordered psychiatric exam and given testimony in her case. Glass strongly suspects that Catherine is a narcissist incapable of telling the difference between right and wrong. Tramell begins to play mind games with Glass, who becomes increasingly frustrated with, yet intrigued by, this mysterious woman. Soon, Glass’s own life begins a spiral of destruction.
One night, Glass goes on a date with Michelle Broadwin, and has rough, violent sex with her after dealings with Tramell. Glass receives a phone call from his ex-wife, Denise, in a state of distress. Her partner, Adam Towers, a journalist writing a negative story about Dr. Glass, has been found strangled to death. Glass suspects that Tramell committed the murder and is attempting to frame him for it. More murders begin to surface around Glass as his obsession with Tramell grows and his career and life are threatened – he finds his ex-wife in a bathroom with her throat slit after they have an altercation in a bar. Later, Dicky Pep is killed – eventually, he himself can no longer tell right from wrong, and the police begin to suspect Glass of involvement in the crimes. He confronts Tramell at her apartment where they engage in passionate sex.
The situations comes to a head during a confrontation between Glass and Tramell at her apartment where, after a struggle, Glass attempts to kill Tramell. Tramell gives Glass a copy of the draft of her next novel, titled The Analyst. After reading it, he realises that Catherine has novelised most of the recent events with herself and other people related to Glass, even himself, as characters. Then it turns out that the character based on herself is going to kill a therapist based on Glass’s colleague, Dr. Milena Gardosh.
Glass runs to Gardosh’s apartment to warn her, finding Tramell there to his dismay. Gardosh tells him that he is no longer in charge of Tramell’s therapy and that he’s going to have his license revoked, due to bad practice regarding Tramell’s treatment. There is a struggle between Glass and Gardosh, in which the latter is knocked out. Catherine then threatens Glass with a gun she carries, but Glass takes it away from her. When Washburn arrives at the scene, Glass shoots him because Tramell told him he had killed the girlfriend of one of Glass’s patients just to “nail him”.
In the final scene, Tramell pays a visit to Glass at a local mental hospital where he has been institutionalised, and he learns from her that the subject of her latest best-selling novel was a man very much like him. Tramell claims that she manipulated Glass into committing all those murders for her own amusement, and flashbacks are shown of Glass committing the murders. Tramell leaves with a wicked smirk on her face, while Glass continues to sit silently in his wheelchair, stymied by frustration and rage.