On a dark and stormy night, six strangers- Col. Mustard (Martin Mull), Miss Scarlet (Lesley Ann Warren), Mrs. White (Madeline Kahn), Mr. Green (Michael McKean), Prof. Plum (Christopher Lloyd), and Mrs. Peacock (Eileen Brennan)- meet for dinner at a mansion belonging to an unknown host. After everyone arrives, butler Wadsworth (Tim Curry) informs the group that they all have something in common- they're being blackmailed by their host, Mr. Boddy (Lee Ving). When the lights go out and Mr. Boddy is found dead, it is up to the dinner guests to figure out who killed him. But as more visitors arrive, and more bodies pile up, it becomes clear that nobody is above suspicion and nothing is as it seems.