Isso se assemelha a uma lembrança confusa de partes de De Volta para o Futuro 3 .
A garota no passado (Clara Clayton) é na verdade o interesse amoroso da figura do pai (Doutor "Doc" Emmet Brown). Aquele que o jovem (Marty mc Fly) vê no presente é seu próprio interesse amoroso, Jennifer.
Da Wikipedia:
Clara applies the emergency brake and runs back to town. She discovers Doc's model of the time machine and rides after him. Having stolen the train at gunpoint, Doc and Marty begin pushing the DeLorean along the spur line, attempting to get it up to 88 miles per hour. Clara boards the locomotive while Doc climbs towards the DeLorean.
Marty arrives on October 27, 1985, escaping the powerless DeLorean before it is destroyed by an oncoming freight train. He discovers that everything has returned to the improved timeline and finds Jennifer sleeping on her front porch. He uses the lessons he learned in 1885 from being goaded into a street race with Douglas J. Needles, avoiding a possible automobile accident.
Marty takes Jennifer to the time machine wreckage. A locomotive equipped with a flux capacitor appears, manned by Doc, Clara, and their two children Jules and Verne. [...] Doc’s train converts into an aerial craft and disappears into an unknown time.