Back to the Future Part II
Back to the Future Part II is a 1989 American science fiction film directed by Robert Zemeckis from a screenplay by Bob Gale; both wrote the story. It is the sequel to the 1985 film Back to the Future and the second installment in the Back to the Future franchise. The film stars Michael J. Fox, Christopher Lloyd, Lea Thompson, and Thomas F. Wilson with Elisabeth Shue (replacing Claudia Wells), and Jeffrey Weissman (replacing Crispin Glover) in supporting roles. It follows Marty McFly (Fox) and his friend Dr. Emmett "Doc" Brown (Lloyd) as they travel from 1985 to 2015 to prevent Marty's son from sabotaging the McFly family's future. When their arch-nemesis Biff Tannen (Wilson) steals Doc's DeLorean time machine and uses it to alter history for his benefit, the duo must return to 1955 to restore the timeline.
Plot
On October 26, 1985, Dr. Emmett "Doc" Brown arrives unexpectedly in the DeLorean time machine. He persuades Marty McFly and his girlfriend, Jennifer Parker, to travel to the future with him and help their future children, with Biff Tannen witnessing their departure. Once they arrive in 2015, Doc incapacitates Jennifer, leaving her asleep in an alley to avoid letting her learn about her own future. Doc explains that their son Marty Jr. will be arrested for participating in a robbery with Biff's grandson Griff, leading to a chain of events that destroys the McFly family.