As many things do, it begins with a post on Tumblr.
Here’s the relevant text:
I think Clara might be dying.
She was trying to tell both the Doctor and Danny something not good.
At the end of this episode, Clara said to the Doctor: “There’s something that I have to tell you, and its not good news, so just listen.”
In Dark Water, she says she has “things to say, not all of them good.”
She seemed convinced that she would never say “I love you” to another man romantically after Danny, despite the fact that she is very young.
In Dark Water, there is a book on Clara’s bookcase on menopause.
Early onset menopause can be caused by chemotherapy.
There was also a post-it that said “three months.”
Clara has been incredibly suicidal throughout these two episodes, maybe even stretching beyond grief.
There have been repeated references throughout the season to Clara’s mortality and impending death.
This season has repeatedly focused on energy emissions (radiation), and the idea of Clara “malfunctioning.”
If Clara is sick enough to be dying, receiving chemotherapy or some similar treatment, then it is only reasonable that she has been WEARING WIGS ALL DAMN SEASON.
And that explains the hair.
I’m going to go cry now.
ETA prior commentary.