The special episode marks Peter Capaldi’s final episode as the 12th Time Lord and sees Jodie Whittaker make her debut in the episode when the Doctor regenerates into his 13th incarnation.
David Bradley will be taking on the mantel of the first Doctor, originally played by William Hartnell and Bill Potts (Pearl Mackie) returns for one last adventure.
‘Twice Upon A Time’ will pick up from the Doctor Who season 10 finale in which the Doctor was resisting regeneration.
Mark Gatiss will play a character simply known as The Captain, who is a member of the British Army in the First World War. Nikki Amuka-Bird will be providing the voice of the glass woman in the episode. And Pearl Mackie will be making a comeback as companion Bill Potts for one last adventure.
Twice Upon A Time was written by outgoing Doctor Who show runner Steve Moffat and marks his final story on the sci-fi series.