In 1954, on a dark and stormy night, six individuals with pseudonyms—Mrs. Peacock, Mrs. White, Miss Scarlet, Mr. Green, Colonel Mustard, and Professor Plum—are invited to a mysterious mansion. Upon arrival, they are greeted by the butler, Wadsworth, who reveals that they are being blackmailed by their absent host, Mr. Boddy. As the guests convene, they are each given a weapon: a candlestick, a knife, a lead pipe, a revolver, a rope, and a wrench. The tension mounts when Wadsworth proposes a plan to expose the blackmailer, but before the plan can take effect, the lights go out, and a murder is committed. With a dead body on their hands and no way to contact the authorities, the group is spurred into a frantic quest to identify the killer among them.

The mansion becomes a web of secret passages and hidden motives as the guests split up to search for clues. Suspicions flare and accusations fly, as each character's sordid past and connection to the victim comes to light. When a second murder occurs, panic ensues, and the urgency to unravel the mystery intensifies. Working against time and the threat of their own demise, the group must put together the pieces of this deadly puzzle, facing their own secrets and lies, to unmask the murderer before anyone else falls victim to the hidden hand wielding death in the mansion's shadowy corners.