There are three seperate timelines in which schoolteacher
Clara Clayton (portrayed by actress Mary Steenburgen
in Back to the Future III
) exists. Thanks to some time travel
meddling by Doc Brown
and Marty McFly
, Clara's life unfolded in three drastically different ways.
In the original timeline Clara was born sometime in the mid-19th century. She was quarentined for three weeks due to illness in her youth, and it was during this time that she developed a love for science and the writings of Jules Verne. In September 1885 she accepted a job as a schoolteacher in the new town of Hill Valley and arrived at the town train station where, unfortunately, nobody was around to meet her. Alone, she rented a buckboard and horses to take her to her new cabin and schoolhouse, but instead a snake spooked the horses and her wagon crashed into the Shonash Ravine which was later renamed Clayton Ravine in her honor. The story of a teacher falling to her death sparked many students' imaginations, as by 1985 most every student at Hill Valley High School knew of a teacher they wanted to toss into the ravine.
When Doc Brown accidentally found himself in 1885 as a result of a mishap with his DeLorean time machine, he set up a shop in Hill Valley and became involved with the community. It was this involvement that led him to volunteer to meet Clara when she arrived on the train. It was love at first sight for the two, and their relationship cut short when three days after their meeting local outlaw Buford Tannen shot the Doc in the back over a matter of eighty dollars. Clara arranged to have him buried in the old cemetary on the outskirts of town.
While stuck in 1955 Marty McFly learned of the Doc's death and, working with the scientist's 1955 counterpart, drove a repaired DeLorean back to 1885. Marty, going by the name of Clint Eastwood, informed Doc of his fate and he decided not to meet Clara at the train station but to instead work on a way to get both he and Marty back to the future. Again, because nobody was at the station to meet Clara she rented a wagon and horses, rode off into the desert, and found herself headed straight for the ravine. This time around, however, Doc and Marty were nearby and came to her rescue. True love struck once more and their relationship began to grow. At the town festival the following weekend Buford Tannen once again tried to shoot the Doc, but a quick toss of a pie pan by Marty saved the day.
Doc insisted on remaining in 1885 with Clara, but Marty convinced him that he didn't belong in the old west. Doc went to say goodbye to Clara and explained how he had to go back to 1985, but she saw his explanation as hurtful lies. Doc went into town to drink his troubles away.
The next morning Clara was on the morning train out of town when she overheard another passenger talking about how depressed the Doc was the night before at the saloon. She stopped the train and went running back to his shop, but instead of finding him she found the DeLorean model mock-up that explained the plan for getting back to the future. Clara climbed aboard a horse and set off after her love. She caught up to Doc and Marty just after they'd hijacked a train to use to accelerate the DeLorean up to 88mph. She climbed onto the moving train and blew the whistle, grabbing Doc's attention. He went back to save her from the impending train wreck that was to follow and, in doing so, missed his only chance to return to 1985.
At some point in the future Doc Brown and Clara were married and had two children: Jules and Verne. In his spare time Doc constructed a new time machine out of a train that, unlike the DeLorean, ran on steam. After taking the time train to the future for a hover conversion, he and Clara returned to 1985 for a few moments to pick up Doc's dog Einstein, and then the family set off for another date in history.