Back to the Future Part III

Marty McFly, stranded in 1955, receives written word from his friend, Doctor Emmett Brown, as to where the DeLorean time machine might be discovered. An terrible finding, on the other hand, leads Marty to come to his friend's rescue. Marty journeys back in time to the old west, where his companion has run afoul of a group of thugs and fallen in love with a local schoolteacher. Marty and Emmett design one last opportunity to send the two of them back in time using period technology.