The Dentist

On the day of his wedding anniversary, Dr. Alan Feinstone discovers Brooke is cheating with the poolman, Matt. He retrieves his pistol and pursues Matt in his car. The chase leads him to Paula Roberts' house, a friend of Brooke's, where Alan watches Paula invite Matt inside. He concocts a story about a surprise party for Brooke.

Alan follows Matt to Paula Roberts' house and watches as Paula invites him inside. Paula's dog attacks Alan during the encounter, and he shoots the dog in self-defense. After the confrontation, Alan heads toward his own car and drives away, still determined to find Matt.

At his dental practice, Alan's first appointment goes awry when he hallucinates a child patient with rotten teeth and accidentally stabs him. The disturbing incident foreshadows his escalating violence and mental unraveling. He ends the appointment visibly shaken and isolated.

As Detective Gibbs investigates Paula's dog's death, Alan treats April Reign, a beauty queen. He hallucinates that April is his wife and, while she is unconscious, engages in inappropriate behavior and then assaults her. He hides her pantyhose, and Steve Landers warns of potential lawsuits before Alan ends the day early and sends staff home.

That night, Brooke meets Alan in a newly created opera-themed room at his practice. He sedates her under the pretense of cleaning her teeth, then pulls out her teeth and cuts off her tongue. The brutal act marks a dramatic escalation in Alan's violence.

The next morning, Detectives Gibbs and Sunshine come to the Feinstone house to question Alan. After they leave, Matt discovers Brooke alive but sedated, and Alan stabs Matt to death in a fit of rage. The murder underscores Alan's complete transformation into a serial killer.

Sarah and Paula wait at the practice while Alan treats Paula with an abusive drilling session, destroying her tooth. His assistant Jessica questions his behavior, and he fires Jessica after she helps Paula leave. Jessica then pulls out April's pantyhose and threatens to expose him, prompting Alan to kill Jessica.

At the dental office, IRS agent Marvin Goldblum tries to leverage Alan's tax problems for a payout and a free dental exam, but Alan tortures him instead. The agent's demand for a payout escalates the peril surrounding Alan and deepens the institutional pressure against him.

Detectives Sunshine and Gibbs drive to the Feinstone house to question Alan further. Near the pool they discover Matt's body, and they break into the house to find Brooke mutilated but alive, tied to the bed. The investigation tightens as the net closes around Alan.

Karen, another assistant, finds Marvin still in the dental chair and warns Alan. Alan attacks Karen and kills her by injecting air into her jugular vein. The body count continues to rise as the detectives close in.

Alan removes Sarah's braces and imagines her teeth rotting. He grabs a gun, but Sarah escapes and hides in a dental room. She encounters Marvin, blood-soaked, who attacks Alan before the detectives arrive to rescue Sarah.

Detectives arrive to rescue Sarah but are too late to capture Alan. They trail him to a university, signaling a climactic pursuit through an academic setting. The chase escalates as Alan's break from reality deepens.

At the university, Alan maniacsically teaches dentistry and orders his students to pull their patients' teeth. He hallucinates and shoots a dental student he mistakes for Matt. The detectives burst in, but Alan uses a hostage to escape.

Alan wanders into an auditorium where an opera singer practices. The singer transforms into Brooke, who laughs at him as he reaches out. Defeated, he is arrested by the detectives in a bleak, theatrical finale.

Alan is carted off to a psychiatric hospital for treatment. In a grim coda, his toothless wife Brooke appears as a dentist, working violently on his mouth, suggesting a disturbing reversal of power and control.