Biff Tannen brags that he has an old, 1800s deed to the ranch of Jennifer Parker, and that he plans to evict her. Determined to help, Marty races back to the Wild West era, where he discovers that Tannen's outlaw ancestors swindled the Parkers out of their land. Unfortunately, the only way Marty can stop the scheme - is to saddle up with Tannen's gang.
Because Verne spends too much time at the arcade, His video game privileges are revoked by his parents. Jules Helps transmit Verne's favorite game to the family TV, but a glitch zaps the video characters into reality. Now Verne must test his skill against the real-life Demon Monstrux, who threatens to make everyone into his Brussels sprout-eating servant.
Tired of being an unpopular "brainiac," Jules grows himself a money tree. As the rich kid at school, Jules finds he has plenty of new-found "friends." But when news of the amazing tree gets out, it attracts the unwelcome attention of greedy minded Biff Tannen, as well as the suspicions of the FBI. Suddenly, Jules discovers the main thing money buys is trouble.