The final installment finds Marty digging the trusty DeLorean out of a mineshaft and looking for Doc in the Wild West of 1885. But when their time machine breaks down, the travelers are stranded in a land of spurs. More problems arise when Doc falls for pretty schoolteacher Clara Clayton, and Marty tangles with Buford Tannen.

Marty and Doc are at it again as the time-traveling duo head to 2015 to nip some McFly family woes in the bud. But things go awry thanks to bully Biff Tannen and a pesky sports almanac. In a last-ditch attempt to set things straight, Marty finds himself bound for 1955 and face to face with his teenage parents -- again.