In late 1967, a young orphaned boy goes to live with his loving grandma in the rural Alabama town of Demopolis. As the boy and his grandmother encounter some deceptively glamorous but thoroughly diabolical witches, she wisely whisks him away to a seaside resort. Regrettably, they arrive at precisely the same time that the world's Grand High Witch has gathered.

A radio astronomer receives the first extraterrestrial radio signal ever picked up on Earth. As the world powers scramble to decipher the message and decide upon a course of action, she must make some difficult decisions between her beliefs, the truth, and reality.

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.

Eighties teenager Marty McFly is accidentally sent back in time to 1955, inadvertently disrupting his parents' first meeting and attracting his mother's romantic interest. Marty must repair the damage to history by rekindling his parents' romance and - with the help of his eccentric inventor friend Doc Brown - return to 1985.

A man with a low IQ has accomplished great things in his life and been present during significant historic events—in each case, far exceeding what anyone imagined he could do. But despite all he has achieved, his one true love eludes him.