10 Paradoxes That Should Break Back To The Future

4. Doc Should Know He's Going To Die, Marty Can't Save Him

Now stuff starts to get really, truly brain-melting. Back one more to the third film in the series, where the whole crux of the plot is Marty going back to 1885 to rescue Doc Brown who is not only stranded in that time period, but is also due to be shot in the back and killed by Biff's ancestor, Buford "Mad Dog" Tannen. Right there you've got a paradox, because Marty finds that out in conjunction with the 1955 Doc Brown, who should by all rights evaporate from the timeline there and then. Dude sees his own grave. That's pretty hardcore, but it's also a hell of a paradox. That's not the end of it, though. So that's admittedly confusing, but in Back To The Future Part III we're dealing with two separate Doc Browns: the young 1955 model who helps Marty out, the older 1985 super genius who has found himself stranded in the Old West. Which surely means that the older Doc Brown would know he was due to be shot in the back, since younger Doc Brown read it in a newspaper. They're one and the same person. The young Doc Brown grows up to be the old one, who knows he's going to be shot and killed before he ever gets stranded in 1885, so surely with that knowledge he should be able to stop it without Marty's intervention? That would make for a shorter film...