The BBC have released a synopsis for the final episode of Series 9, Hell Bent. You can read the synopsis below:
If you took everything from him, betrayed him, trapped him, and broke both his hearts...how far might the Doctor go?
Returning to Gallifrey, the Doctor faces the Time Lords in a struggle that will take him to the end of time itself. Who is the Hybrid? And what is the Doctor’s confession?
Hell Bent airs on Saturday 5th December on BBC One, the time is yet to be confirmed.