Marty, Jules and Verne head back to the 1850s, where they meet Jules and Verne's maternal grandparents, Daniel and Martha. Unfortunately, Martha falls in love with Marty instead of Daniel, and Clara is in danger of never existing. Things get worse when Martha is kidnapped by Wild Bill Tannen...

Marty and Verne travel to 1500s Caribbean, where Verne hopes to get an earring and Marty has to deal with pirate Mac The Black.

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.

Jules tries to grow a money tree to become popular at school, which leads to troubles with the media and the FBI.

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.

Verne and his new friend, Chris, go see a 1930s circus, which the owners are about to lose to landlord Farmer Tannen.

Running away from home, Verne uses the DeLorean to travel back in time. When Doc, Marty and Jules go after him, they arrive in the middle of the Civil War where Jules and Verne get caught up on different sides.

Marty takes the place of his ancestor, pitcher Pee Wee McFly, to help his team win a 1897 Pennant game. But a nasty gangster named Diamond Jim Tannen wanted Pee Wee to lose.

Jules and Verne pull a string of April Fool's Day pranks on Doc, tampering with his inventions. Unfortunately one of them, the Brain Wave Analyzer, causes Doc to think his days in science are over and he retires.

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.

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.

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.

After finding a strange craft in Doc's bushes, Biff claims Doc is an alien and everyone believes him. In 1967, Marty, Jules and Verne arrive to discover the truth.

It's Christmas time so the Brown family and Marty go to 1800s London to celebrate. Unfortunately, the boys lose the key to the DeLorean to a pickpocket and Clara, a toy shop manager and his family get thrown into prison by Ebiffnezer Tannen.

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!

After Biff plans to evict Jennifer's family from their ranch, Marty goes to the Old West to stop Biff's family from getting the ranch deed.

Verne gets sick of his name after kids keep making fun of him and goes to great lengthes to get it changed, even going back to see his parents just before he's born.

While at the Brown house, Doc's hair cutting invention wreaks havoc on Marty's hair. Marty and boys go to find Doc, who is with Clara at the 1904 World's Fair, to fix this mess. But Marty then gets put in a side show by P.T. Tannen.

On a trip to the 1940s, Verne enters a dance contest with his future dance instructor, Dorothy, while Marty gets drafted.

Verne uses the DeLorean to look for something to bring in for show and tell, finding a dinosaur egg. Unfortunately, the egg hatches in the present and it becomes more and more difficult to hide it.

Looking to cure Marty's athlete's foot, Doc and Marty travel back in time to locate an extinct frog in South America, where they have to stop Biffando from stealing the Incas' gold.

Two bank robbers steal the DeLorean and end up outside an Australian prison in 1790. With him having been in the back seat, it's up to Einstein to get himself and these robbers home.

After Jules insults his intelligence and comments that he can't really be a part of the family, Verne starts to think his real father is Benjamin Franklin. Unfortunately, this leads to Verne ruining Franklin's famous electricity experiment and it's up to Doc to set things straight.

It's Doc and Clara's anniversary and the kids get them tickets for a cruise, which takes place in 2091 and takes them into space. Unfortunately, Ziff Tannen sabotages the cruise ship.

Doc and the boys travel back to prehistoric times to test a new invention and Doc stops a meteor from colliding with Earth. They don't realize they changed history until they return home and find a civilization where dinosaurs rule!