Quote Originally Posted by Calemyr View Post
Oswin:
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Oswin says point blank that the Alaska was her first adventure. If Clara is Oswin at an earlier date, and she becomes the new companion, that means that her timeline has already been drastically altered by that fact. We're talking Time War level causality warping, here. Taking Oswin out on tour means she won't be on the Alaska, she won't be converted, she won't spend a solid year screwing with the asylum, and she won't scare the hell out of the Daleks. Then they won't call the Doctor, Oswin won't rewrite the Daleks, the Daleks won't forget him, and the Doctor won't have a reason to recruit Clara. So she does go on the Alaska and the episode happens as normally. Paradox.

Of course, it could be intentional. But what would be bad enough that the Doctor would intentionally undo the mindwipe and resurrection of the Pond marriage?
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Clara? Who?

As to undoing the mindwipe, I'm guessing that'll happen When Silence Falls.