The plot of Thinner concerns massively overweight lawyer Billy Halleck (Robert John Burke), who is receiving an oral gift from his wife (Lucinda Jenney) while driving down the street one night, when he becomes so carried away that he runs over an old Gypsy woman (Irma St. Paule), killing her. Nobody in town likes the traveling Gypsies much, so Hallecks pals -- a judge and a cop -- cover up the incident. After the cover-up, the dead womans father, Tadzu Lempke (Michael Constantine), touches Hallecks face and whispers thinner. Pretty soon, Halleck is losing weight at an incredible rate of more than 40 pounds a week. He tries everything, but learns that Lempke is the only man who can remove the curse. In the meantime, the judge dies of a mysterious skin ailment, and the cop commits suicide. When begging and pleading with Lempke doesnt work, Halleck turns to more drastic methods of persuasion. ~ Robert Firsching, All Movie Guide