Doc causes another power cut in his lab whilst trying to invent something. Jules and Verne are annoyed because their toy car racing has been interrupted (it runs on electricity) and Clara is annoyed at the lack of power as well. Feeling that his family has become too dependant on technology since they moved to the 20th Century, Doc uses the DeLorean to take his family back to Medieval England. The family are not happy, especially when Doc sends the DeLorean several hours into the future so there is no way they can go home until then. Clara walks off and after meeting some Medeival women washing in the river she meets Lord Biffingham of Tannenshire. Biffingham takes a shine to Clara and when she turns him down he kidnaps her. Doc tries to save her but eneds up being kidnapped as well. Biffingham imprisons Clara in his tower and decides to marry her - once she has become a widow! And he plans her to be a widow very shortly by challenging Doc to a joustling match.

When Doc was four, he fell into a river during a fishing trip and has had a fear of it happening again ever since. After the boys learn about this, they and Marty try to change it. But they regret it when it leads to a mishap with a stunt plane, causing young Emmett Brown to become a famous daredevil.

Marty and Verne meet Mr. Wisdom, who hosts a popular children's science show. As it turns out, Doc and Mr. Wisdom were college roommates. Doc doesn't recall it with fondness, as Mr. Wisdom stole his invention for a science fair and won. Things apparently haven't changed as Mr. Wisdom has stolen the DeLorean!

Characters from Verne's new favorite video game, BraveLord and Monstrux, come to life in a weird accident. Doc can't fix this situation because he's been sent into the game.

Just before the Founder's Day Celebration, the town loses all its electricity again because of Doc. His attempt to fix it makes things worse, causing everyone to want the Brown family kicked out of town.

Marty and the boys learn Doc had a stint in wrestling during the fifties, but never really competed. Travelling back in time, Marty and the boys attempt to get Doc to enter the ring. This unfortunately leads to him getting hit on the head and becoming a bumbling superhero.