Generally, the film is a dark and quirky "tragicomedy". The "everyman" protagonist, Dr. Frank Sangster (Steve Martin), is a dentist with a fairly pleasant but rather innocuous, ordinary and uneventful life. But all of this gets derailed, and Frank's life descends into an increasingly complex mess, from the minute a beautiful and seductive new patient named Susan Ivey (Helena Bonham Carter) comes to him, seeking a root canal and a little pain relief...
On Susan's initial office visit, Frank schedules her for a root canal the very next day, and offers her some Ibuprofen to address her pain in the meanwhile. Claiming that she is allergic to the offered medication, Susan requests a prescription for the addictive pain-killer Demerol. Frank provides the prescription, but only for five tablets. However, Susan changes the dosage from five tablets to fifty when she collects the medication from her pharmacist.
Susan arrives for her appointment twelve hours late, having mistaken the time. She seduces Frank, talking him into getting drunk and having sex with her. During the night, Susan steals all of Frank's narcotics. The next day, there is a DEA (Drug Enforcement Administration) agent at Frank's office demanding to see the dentist's narcotics supply, because an 18-year-old has driven a car off a cliff under the influence of cocaine hydrochloride from a bottle registered to the dentist. Knowing that Susan has stolen his entire drug supply, Frank puts the agent off, saying he dispensed it all to patients. The agent leaves with the promise that if Frank fails to produce the empty containers in two days, the DEA will place him under arrest.
That night Frank goes to Susan's hotel room to demand the empty containers, threatening that he'll call the police if she doesn't provide them. Once again, she overrides his initial intentions and seduces him - with the result that they have sex and he spends the night with her.
The next day at his office, Frank is confronted by Susan's brother, Duane Ivey (Scott Caan) having a violent scene, saying: "Stay the hell away from my sister" and "I don't appreciate your threats". Duane ends the conversation with, "I don't ever want to see you again, because if I do, goddamn it, I'm gonna hurt you."
That night, Frank returns to Susan's hotel room and, assuming that Susan is the form he sees the bed, starts talking to her. The person under the blanket turns out to be not Susan but brother Duane, who leaps up and attacks Frank, attempting to strangle him. Frank takes scissors from a nearby desk and stabs Duane in the hand, impaling him and embedding the scissors. Frank flees, stopping off at a bar to calm down. On arriving at home, just minutes ahead of his girlfriend Jean (Laura Dern), he finds Duane dead on the floor.
Police arrive on the scene to question Frank. Comically adding to Frank's distress and anxiety is actor Lance Phelps (Kevin Bacon), a hack actor doing research for a role, and permitted by the police to question Frank at aggressive levels that cause Frank heightened discomfort. After the police arrive and depart, Frank tells Jean about the whole ordeal.
A while later, Frank is arrested for the murder of Duane Ivey based on finding Frank's teeth marks on the body - that someone else put there after killing Duane. After Frank breaks free, all of Chicago is on the look out for him. He goes to his office in the night, only to find his brother Harlan lying dead.
At this point, it is revealed that Frank's girlfriend Jean is behind all of the killing. She killed Duane with a shotgun and created dentures of Frank's teeth using his dental equipment and bit Duane's corpse with them. She was also in cahoots with Harlan, with whom she was having an affair. Unfortunately for Harlan, her plan was to eventually kill him as well with the shotgun to tie up all loose ends and make it appear that Frank killed him after Duane.
Realizing he'll never be free without starting over, Frank pulls out all of his dead brother's teeth, as well as all of his own. Frank uses his dental skills to place his own teeth into his dead brother's skull, and then sets fire to the dental office with Harlan's corpse, replete with replaced teeth, left inside. Frank and Susan, now lovers, escape to France, where they live happily ever after in a little cottage on the countryside.
Meanwhile, Jean's attempts to frame Frank fall apart. Unbeknownst to her, Harlan was playing with a medical video camera while he was shot and the recovered footage shows Jean firing the shotgun at the camera holder but fails to show it was Harlan who was shot. Therefore, the police wrongly assume that Jean shot Frank and arrest her.
The film received a decided mix of reviews. Roger Ebert of the Chicago Sun-Times found the "screwball film noir" funny "all the way through," and declared its "loopholes" forgivable for a comedy. The Los Angeles Times review had high praise for Martin's portrayal, and most of director Atkins' work, but found the appearance by Kevin Bacon "ludicrous", and the film's tension reduced by the "virtually slapstick run from the cops". Salon Magazine's review found the film "so aggressively stylish that it comes off more like a stunt", its plot "plodding", and though Laura Dern's performance made the film "clack along efficiently when she's onscreen," with the film's "feebly shocking conclusion, we're left feeling heavily sedated, and not in the good way." The Rotten Tomatoes review aggregator showed, among 29 "top" reviewers, 9 "fresh" and 20 "rotten" reviews.
The film grossed $2 million in the United States, and nearly $500,000 in foreign markets, with a production budget of $8 million.