Directed by Robert Zemeckis, "Back to the Future 2" picks up where the first film left off. Marty McFly (Michael J. Fox) and his friend, Doc Brown (Christopher Lloyd), travel to the year 2015, where they encounter a futuristic world that's both fascinating and unsettling. However, their actions in the future put their own existence in jeopardy, and they must ensure that their timeline remains intact.