In a futuristic city sharply divided between the rich and the poor, the son of the city's mastermind meets a prophet who predicts the coming of a savior to mediate their differences.

Eighties teenager Marty McFly is accidentally sent back in time to 1955, inadvertently disrupting his parents' first meeting and attracting his mother's romantic interest. Marty must repair the damage to history by rekindling his parents' romance and - with the help of his eccentric inventor friend Doc Brown - return to 1985.

The final installment finds Marty digging the trusty DeLorean out of a mineshaft and looking for Doc in the Wild West of 1885. But when their time machine breaks down, the travelers are stranded in a land of spurs. More problems arise when Doc falls for pretty schoolteacher Clara Clayton, and Marty tangles with Buford Tannen.

After recovering from injuries sustained in the mob attack upon himself and his creation, Dr. Henry Frankenstein falls under control of his former mentor, Dr. Pretorius, who insists the now-chastened doctor resume his experiments in creating new life. Meanwhile, the Monster remains on the run from those who wish to destroy him.

Conducting clandestine experiments within the morgue at Miskatonic University, scientist Herbert West reveals to a fellow graduate student his groundbreaking work concerning the re-animation of fresh corpses.