New England, 1954. Six guests, known under the assumed names of Mr. Green (Michael McKean), Colonel Mustard (Martin Mull), Mrs. Peacock (Eileen Brennan), Professor Plum (Christopher Lloyd), Miss Scarlett (Lesley Ann Warren) and Mrs. White (Madeline Kahn), are summoned to a secluded mansion, Hill House, on a stormy night. They are greeted by the British butler, Wadsworth (Tim Curry) and the French maid, Yvette (Colleen Camp). Over dinner, it is revealed that each guest lives in the District of Columbia or is employed by the government. A seventh guest arrives: Mr. Boddy (Lee Ving).

The whole cast gathers in the study, where Wadsworth reveals the reason they have been gathered together. One by one, he reveals the each of the guests are victims of blackmail. Wadsworth later explains that Mr. Boddy is the man who has been blackmailing them all and that the police will arrive in forty-five minutes.