[Lost Cause]

Originally Posted by Vallen Chaos Valiant

Here is my theory:

Spoiler for Snowman spoiler:

Clara is a technical immortal. But not by not dying; she survives death by arranging the atoms in the universe so a close approximation of herself gets created and born. She is a REINCARNATOR. This might sound extreme, but keep in mind that it is nothing more than a much slower and much more bothersome variety of TimeLord regeneration.

The preview implies that they are going to meet multiple varieties of Clara in Time and Space. Makes sense; there must be thousands of Claras in the universe, if she kept being reborn.

Considering the possibilities of parallel deminsions, worm holes, time distortions, and such. It's possible for anyone to have multiples of themselves roaming the universe.
But what's to stop the Doctor from interceding before the Alaska crashes into the Dalek Asylum? In any event it shall be interesting and fun!