What really happened in the movie!!!!
The director says the ending was left ambiguous to make the viewer think and for them to make the killer whoever they wanted it to be. I dont agree with this.
SHARON STONE WAS THE KILLER!!
The movie doesn't make any sense other wise.
The plot is that Catherine Tramell has Risk Addiction. This is why she is masturbating in the car in the beginning because she wants to live on the edge and see how far she can keep in control. She is taken in for questioning when her latest risk turns deadly and her soccer player lover dies. She automatically hates detective Washburn who sends her to a psychiatrist for analysis a Dr. Micheal Glass. Dr. Glass tells the courts that she is omnipotent and manipulative and will increase her wild behavior to see how far she can take risks which may allow her to be a threat to herself or others. Dr. Glass is the first person to get under Catherine Tramell's skin and actually figure her out. She hates this and sets out to royally screw him over and totally ruin him and his personal and professional life. Catherine starts getting involved with people in Dr. Glass's life and digs for dirt on him as a motive to take him down. Tramell discovers that Dr. Glass was involved with a patient who ended up killing and Dr. Glass might have known about it before hand. Dr. Glass is up for the Douglas Chair, a prestigeous position in the psychiatric community and something this big getting out could ruin him. Tramell has a sexual relationship with Adam Towers a magazine writter out to expose Dr. Glass and she kills him to set it up to look like it could be Dr.Glass who did the killing because Towers was about to expose him. She moves on to kill Dr.Glass's ex wife whom Towers was having an affair with and who was about to testify against Dr. Glass further incriminating him. Catherine Tramell weaves a complex web and sets up her killing to make it look like he is doing the killing because he has the motives, not her. Tramell also gets involved with Dr Elena Gardosh. She manipulates Gardosh Dr. Glass's closet colleague as a key to ruining his career. When Dr. Glass starts teaming up with Detective Washburn to prove that Tramell is the real killer, she pits the two against each other and Dr. Glass shots Washburn infront of Elena Gardosh just as cops enter totally framing him as the killer and eliminating the one cop who knew the truth. Dr. Glass goes insane and is sent to a sanitariam where he is now a totally destroyed man. Catherine goes to visit him with her new book titled the Analyst. Its about a psychiatrist who goes out of his mind trying to prove a blonde woman is a killer, but the twist of the book is that the Dr. is the one doing the killing. The flash backs we see in the final scenes show the motives Tramell used to make Dr. Glass look guilty. Dr. glass smiles slightly seeing that he got totally manipulated by this woman and she ruined him. Her final and ultimate revenge.
So Catherine Tramell IS THE REAL KILLER but she used Dr. Glass's motives and acted out his unconcious impulses in order to destroy him.
Rewatch the movie a few times and look closely at the scenes in Dr. Glass's office. Catherine Tramell reveals little things like to her a guy is just a guy and that she will eventually forget about them, she has no real emotional attachment to them. However if she is with a person when they die she feels totally emotionally attached to them and will never forget them. Just like Micheal Douglas in the original in order for that relationship to mean something to her she killed him in the end with the ice pick.