<P> The film was produced on a $40 - million budget and was filmed back - to - back with its sequel, Part III . Filming began in February 1989 after two years were spent building the sets and writing the scripts . Two actors from the first film, Crispin Glover and Claudia Wells, did not return for the final two . While Elisabeth Shue was recast in the role of Wells' character, Jennifer, Glover's character, George McFly, was not only minimized in the plot, but also was obscured and recreated with another actor . Glover successfully sued both Zemeckis and Gale, changing how producers can deal with the departure and replacement of actors in a role . Back to the Future Part II was also a ground - breaking project for effects studio Industrial Light & Magic (ILM): In addition to digital compositing, ILM used the VistaGlide motion control camera system, which allowed an actor to portray multiple characters simultaneously on - screen without sacrificing camera movement . </P> <P> Back to the Future Part II was released by Universal Pictures on November 22, 1989 . The film received mixed reviews from critics and grossed over $331 million worldwide, making it the third - highest - grossing film of 1989 . </P> <P> On October 26, 1985, Dr. Emmett Brown arrives in his flying time machine and persuades Marty McFly and his girlfriend, Jennifer Parker, to come back to the future with him to help their future children . Biff Tannen witnesses their departure . They arrive on October 21, 2015, where Doc electronically knocks out Jennifer and leaves her asleep in an alley, explaining that she should not have too much knowledge of future events . He has Marty pose as his own son and lookalike Marty Jr. to refuse an offer to participate in a robbery with Biff's grandson Griff, thus saving both of Marty's children from prison . </P> <P> Marty switches places with Marty Jr. and refuses Griff's offer, but Griff goads Marty into a fight . Griff and his gang are arrested, saving Marty's future children . Before rejoining Doc, Marty purchases an almanac containing the results of major sporting events from 1950 to 2000 . Doc discovers it and warns Marty about attempting to profit from time travel, but before Doc can adequately dispose of it, they are interrupted by the police, who have found Jennifer incapacitated and are taking her to her 2015 home . They pursue, as does Biff, who has overheard their conversation and picked up the almanac which Doc discarded . </P>

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