Ned Racine is an incompetent and sleazy Florida lawyer who begins an affair with Matty, a seductive woman married to a wealthy man. Fearful that her husband would find out about them and leave her penniless, Matty convinces Ned to kill her husband so they can be together.
This film provides examples of:
- Ambiguous Ending: The fact that Ned had gotten concrete confirmation of his theory—and his cop friend indicated that he needed proof to go looking for "Mary Ann". Also, we are left wondering from Matty's/Mary Ann's expression if she partly regrets all she's done.
- Ambulance Chaser: Even before being seduced into a murder plot, it's clear that Ned Racine is a particularly disreputable low-rent lawyer.
- The Bad Guy Wins: The Femme Fatale has effortlessly manipulated the dumb lawyer throughout the film and convinced him to murder her rich husband. She fakes her own death and leaves the country with her late husband's money, while the lawyer is left to take the rap for two homicides.
- Black Widow: Matty/Mary Ann. Seduces her lover into killing her husband, then leaves him to take the rap for this and yet another murder. And in a state like Florida, he could very well be on his way to death row for that.
- Bookends: The film begins and ends with characters commenting on the heat.
- Cassandra Truth: Ned figures out that Matty/Mary Ann is alive. Unfortunately, given his involvement in her husband's murder as well as the numerous other crimes he's committed, no one believes him.
- Chekhov's Gun: Midway through the film, during the meeting concerning the new will, Miles Hardin mentions an earlier case involving an incompetently-prepared will which led to Ned facing a malpractice suit. Ned later learns that Matty heard of this case from the plantiffs' attorney in the suit before she first met Ned, which causes him to realize her duplicity for the first time.
- Chekhov's Gunman: Mary-Ann is the clearer example, due to the uncanny resemblance between she and Matty but a subtler example is the judge who is comically annoyed by Ned's incompetence in the first scene. The fraudulent will comes up in front of him and he voids it to punish Ned out of annoyance.
- Chronic Backstabbing Disorder: Matty backstabs every single person in the movie.
- Corrupt Corporate Executive: Matty's husband is implied to be this. Though he himself comes across as a somewhat likeable fellow, the implication grows throughout the film that his group of businessmen are involved in some pretty crooked stuff—to the point that Ned's D.A. friend notes it's almost a good thing the man is dead.
- Creepy Souvenir: The sunglasses Matty is wearing at the end are set in the glasses frame of her late husband.
- Do You Want to Copulate?: Ned walks up to someone whom he thinks is the wealthy married woman he's having an affair with, straight-up blurting out "Hey lady, do you wanna fuck?". It turns out it's actually one of her friends who resembles her quite heavily, who snarks that the locals sure are friendly.
- Downer Ending: Ned finds himself manipulated into taking the rap for two murders while Matty/Mary Ann makes off overseas with her dead husband's money.
- Empathic Environment: The film takes place during an especially hot Florida summer, setting the perfect scenery for a plot centered around sexual desire for a woman leading a man to his doom.
- Faking the Dead: Matty/Mary Ann makes it seem like she died as a result of her own bomb, in order to frame Ned for her "death" and run off with the money they had stolen from her murdered husband.
- Femme Fatale: Kathleen Turner, in spades.
- Film Noir: Solidified the genre's return.
- Hotter and Sexier: Specifically, to Double Indemnity and (less directly) The Postman Always Rings Twice, actually showing the sexuality those earlier films could only hint at. More generally, the film is one for Film Noir in general—and in being so, it helped set the standard for the Film Noir-Erotic Film trend of The '80s and The '90s.
- Informed Attribute: Matty's husband is implied more than once to have been involved in some shady business, but we see none of this onscreen and the man is pretty jovial in most of his scenes.
- Loophole Abuse: Matty goes behind Ned's back and forges a new, poorly-written will that, under Florida law, will be automatically voided and leave Edmund's entire estate to her.
- Mistaken from Behind: Provides both a bit of comic relief and a Chekhov's Gun when Ned thinks he sees Matty in the garden.Ned: Hey, lady! Wanna fuck?
Mary Ann: (turning around) This sure is a friendly town!
- Only Sane Man: Ned's detective friend Oscar, who warns him against sleeping with Matty and eventually unravels the murder plot against Edmund.
- Also Ned's criminal friend Teddy, who is pretty level-headed and tries to dissuade him from what he thinks is merely an arson despite supplying him with the bomb.
- Primal Scene: Edmund's niece walks in on Matty and Ned, but she doesn't get a clear look at Ned's face. After Edmund's murder, it comes back to haunt them when the little girl tells the cops what she saw, though she can't remember what the man looked like. As it so happens, Ned is at the police station on other business when this happens and one of the cops mentions it to him. Knowing that they're suspicious of him and Matty and that if he tries to avoid being seen by the little girl it will confirm that he has something to hide, he calls their bluff by approaching the girl and her mother and directly addressing them.
- Tropical Epilogue: Kathleen Turner's character ends this way, whatever her name may be.
- The Vamp: Mary Ann Simpson is explicitly labeled "The Vamp" in her high school yearbook. She's Kathleen Turner's character, which we've been lead to believe is Matty Tyler Walker, and has been playing Ned Racine, the real Matty Tyler, and her husband for all they are worth.
- Very Loosely Based on a True Story: Like Double Indemnity (which it's a vague remake of), it's based on the Snyder-Gray murder.