Back to the Future Part II is a 1989 American science fiction comedy film and the second installment of the Back to the Future trilogy. It was directed by Robert Zemeckis, scripted by Bob Gale and stars Michael J. Fox, Christopher Lloyd, Thomas F. Wilson and Lea Thompson. Part II and the third installment of the trilogy, Back to the Future Part III, were filmed back-to-back, with some of the scenes of Part II and Part III filmed concurrently, and released six months apart. Although released in 1989 and 1990, both films continued to portray 1985 as the present, as they directly follow the events of the first film.
After Marty McFly returns to 1985 after repairing the damage to history by making his parents-to-be fall in love in 1955, his friend Dr. Emmett "Doc" Brown has him travel to 2015 to prevent his future son from getting involved with Biff Tannen's grandson Griff. However, Biff travels to 1955 and completely alters history. Marty and Doc travel to 1955 to stop Biff so they can restore the original timeline.
On October 26, 1985, Doctor Emmett Brown arrives from the future and tells Marty McFly and girlfriend, Jennifer Parker, he needs help to save their future children from