Back to the Future Part II is a 1989 American science-fiction film directed by Robert Zemeckis and written by Bob Gale. It is the sequel to the 1985 film Back to the Future and the second installment in the Back to the Future trilogy. The film stars Michael J. Fox, Christopher Lloyd, Lea Thompson, and Thomas F. Wilson. The film 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.