Frank (Steve Martin) is living the American Dream. He is blessed with a thriving dental practice and luxury home, and he is happily engaged to beautiful assistant, Jean (Laura Dern).

But his perfect life quickly unravels when Susan Ivey (Helena Bonham Carter), a seductive new patient with an appetite for painkillers, settles into his dentist's chair. Before long, Frank is wanted by the police, plunging him into a shadowy world of drugs, sex and violence...