In 1999, Petey Shelburn tries to destroy a cursed monkey toy, but a chain reaction leads to a grisly death, and he vanishes soon after. His twin sons, Hal and Bill, later discover the monkey among his belongings. When they wind it, horrific deaths follow, starting with their babysitter and eventually claiming their mother, Lois. Hal, wracked with guilt, dismantles and discards the monkey, but it reappears years later, leading to more tragedy. In adulthood, the estranged brothers confront their past when the monkey returns after their aunt’s death. Bill, bitter and vengeful, uses the monkey to manipulate death itself, believing he can control it. He coerces Hal’s son, Petey, into winding the key for safety, but the curse spirals, killing indiscriminately. When Bill tries to force the monkey to kill Hal without warning, it unleashes destruction across the town. The brothers reconcile, but the monkey claims Bill in a final act. Hal and Petey, now its reluctant guardians, vow to keep it dormant. As Death itself passes them by, Hal suggests a dance in memory of Lois, and Petey quietly agrees.