Back to the Future Part II (1989, directed by Robert Zemeckis, starring Michael J. Fox. PG) Marty McFly is enlisted by Doc Brown to travel ahead to the year 2015 to stop his child from making a grave mistake. The plan works, but while Marty is helping his family avoid tragedy, someone borrows the DeLorean and changes the past. Marty and Doc must now travel back to 1955 to stop the changes and avoid crossing paths with themselves.