The final episode in the fast-paced Back to the Future trilogy has time traveler Marty McFly heading back to the Old West to save his pal Doc, the inventor of the magical DeLorean time-traveling machine that took Marty back to the 1950s in the first film and shot him into the 21st century for the second episode. Marty's latest journey began at the end of Part II when he received a letter dated 1885 from Doc, who was accidentally stranded in 1885 by a stray bolt of lightning. The letter says that he cannot come home until he repairs the DeLorean, which he buried in the desert to keep it safe. Marty goes to dig it up so he can fix it and rescue Doc. Unfortunately, he is en route to the sight when he finds a tombstone with his friend's name on it; beneath it are the mysterious words "With Love from Clara." The date reads 1885. Marty realizes that if he cannot prevent Doc's early demise that Doc will never have existed and that will cause all kinds of problems. Unfortunately, no sooner does McFly make it back to the past, where he adopts the name "Clint Eastwood" when he gets into trouble, leaving his forbears to save him. Meanwhile, Doc, who is still alive, falls in love with the beauteous schoolmarm Clara Clayton, the girl he knows he must marry. They meet when he saves her from a runaway wagon. When not wrestling with their own problems, Marty and Doc must figure out how to fix the disabled DeLorean so they can return to the present. Needing the car to go 88 mph before it can breach time, the two devise a crazy scheme involving a stolen train, an uncompleted stretch of track and a yawning gorge that comprises the story's thrilling highlight.