Back to the Future Part II is fiction.
Back to the Future Part II . The film was produced on a $ 40-million budget and was filmed back-to-back with its sequel , Part III . Back to the Future Part III is a 1990 American Science fiction Western comedy film and the third and final installment of the Back to the Future trilogy . 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 , trapped in 1885 , was killed by Biff Tannen 's great-grandfather Buford .