Back To The Future 3's Clara Creates A Doc Brown Plot Hole

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In Back to the Future Part III, the fate of Doc Brown's love interest, Clara Clayton, creates a plothole between the timelines set up within the movie. Before Marty McFly time-travels back to 1885 to save Doc, he finds a tombstone that claims Doc was shot and killed by Buford «Mad Dog» Tannen. The inscription at the bottom reads "erected in eternal memory by his beloved Clara."

Clara Clayton is later revealed to be a schoolteacher in 1885 and meets Marty and Doc when they save her from almost falling into Shonash Ravine. Marty later explains to Doc that in the present, the local kids refer to the ravine as "Clayton Ravine" due to a teacher having died there a century ago. Doc pieces together that Clara was supposed to die in the ravine that day, and that saving her altered history.

Related: Doc Brown Killed Marty — Super Dark Back To The Future Theory Explained

This is where Clara creates a plothole in Back to the Future Part III. The two details that Marty is aware of in the present day —both Doc's tombstone with Clara's name on it and the present-day name for the ravine — come from two completely separate timelines. Marty could not be aware of both, as one takes place in a timeline where neither Doc nor Marty travels back to 1885, and the other takes place in a timeline where Doc gets killed by «Mad Dog.»

In the original timeline, Doc and Marty do not travel back to 1885. Clara Clayton ends up getting sent over Shonash Ravine, which is renamed «Clayton Ravine» in memory of her, and Marty McFly and the other local children grow up knowing the ravine by this name, as well as the story of how Clara died there. This is the timeline without any interference from Doc or Marty and is Marty's established timeline as well since