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.

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!

Marty and Doc head to Ancient Rome, unaware Jules and Verne are joining them. While the boys cause trouble, Marty gets mixed up in a chariot race with Bifficus and Doc gets thrown to the lions.

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.

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.

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, 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...