Back to the Future Part III is a 1990 American science fiction Western film and the third installment of the Back to the Future trilogy. The film was directed by Robert Zemeckis, and stars Michael J. Fox, Christopher Lloyd, Mary Steenburgen, Thomas F. Wilson, and Lea Thompson. The film continues immediately following Back to the Future Part II (1989); while stranded in 1955 during his time travel adventures, Marty McFly (Fox) discovers that his friend Dr. Emmett "Doc" Brown (Lloyd), trapped in 1885, was killed by Buford "Mad Dog" Tannen (Wilson), Biff's great-grandfather. Marty travels to 1885 to rescue Doc and return once again to 1985, but matters are complicated when Doc falls in love with Clara Clayton (Steenburgen).

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, and Jeffrey Weissman 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.