Previous: 12 wakes up in a psychiatric hospital, dazed and confused. He's taken in to therapy as part of his treatment where he starts bugging out, asking why he's here, what's going on. The therapist asks if he's feeling any better and explains he was checked in by "a concerned fellow timelord".
The course of the episode is explaining to the Doctor that his symptoms started with the Time War, the PTSD, 12 explains:
>"I'm over all that now, I, we, that is me saved Gallifrey."
>"Mmhm-hmm."
>"No, we really did, we killed all the daleks too! Gone forever, it was incredible, truly!"
>"Yes, Yes, you keep saying this. That's what you believe."
>"I don't 'believe it', it's true!"
>"But it wasn't true, Doctor. You told yourself it was because that was your way of coping. You haven't been very well, Doctor."
It is explained to the Doctor that he has been going mad. 12's entire run has been a descent into madness, Gallifrey was never saved, the Time War killed both the Timelords and the Daleks.
>"Tell me, what do you remember from before you came here?"
>"The Master, she..."
>"She?"
>"Yes?"
>"Oh dear, dear, dear. Proceed."
>"Well she sacrificed herself for me, you see, then I became a woman, and also there was another me and she was a this strong black lady, and I was born on a different world as a little black girl, not from Gallifrey at all."
>"Ah."
>"What?"
>"Textbook dissociative disorder. Very common with PTSD. You were never any of those things, Doctor, Timelords can't swap race or gender."
It's explained that the Doctor's madness manifested itself through 12's lifetime, with comments about how the future should be all girl, and history being a whitewash. He's been doing it to get away from his reality.
The Doctor is told there is only one way this can be fixed, he has to choose to regenerate. It will cure his mental illness and allow him to progress. 12 Reluctantly does so, and the series proceeds with a new white male Doctor.
