
Marty McFly (Fox) has only just got back from the past, when he is once again picked up by Dr. Emmett Brown (Lloyd) and sent through time to the future. Marty’s job in the future is to pose as his son to prevent him being thrown in prison. Unfortunately, things get worse when the future changes the present.
The second part of the trilogy begins as Doc, Marty and Jennifer take the time-traveling DeLorean into the year 2015 to straighten out the future of the McFly family. But Biff Tannen steals the time machine and gives his younger self a book containing 50 years of sports statistics, which the young Biff uses to amass an enormous gambling fortune and transform idyllic Hill Valley into a living hell. To restore the present, Doc and Marty must return to the events of their previous adventure in 1955 and retrieve the book.