The annual Doctor Who Christmas special is always a big deal, but there’s no denying that this year’s special is bigger than most. As if it isn’t enough that Peter Capaldi is signing off after four seasons as the Twelfth Doctor, he is also being succeeded by Jodie Whittaker, the first woman to ever play the Doctor. So excitement–and plain curiosity–over the episode is at a fever pitch.
Luckily, exiting Doctor Who showrunner Steven Moffat sat down with RadioTimes to give fans the scoop on Capaldi’s–and his–final episode, entitled “Twice Upon A Time.”
When we last saw the Doctor at the end of Season 10, he was about to regenerate but suddenly refused, saying that he was tired of becoming different people all the time. Moffat says that the Christmas special will expand on that premise.
“[The Doctor] is having a strop,” he explains. “In a wintry landscape, he meets the First Doctor (David Bradley taking over for deceased William Hartnell), who is also refusing to change.”
Moffat says that the special will begin by going back to the very first Doctor Who finale, “The Tenth Planet.” Just like in the original, the Doctor will leave his companions, Ben and Polly, behind, but then things take a new twist.
“So then it’s the Twelfth Doctor telling the First that he has to regenerate — and realizing he must as well. This is the moment where he decides whether or not to go on. And it will mark the only time that David Bradley has played a younger version of Jodie Whittaker.”
Moffat promises that it’s not as depressing as it sounds.
“This is Christmas Day, so we’re not going to have an hour of two suicidal Doctors. That’s not appropriate for Christmas Day or Doctor Who. There’s a tradition of the Doctors being funny when they get together. When Doctors meet, it’s a laugh.”
He also says he knew that the Thirteenth Doctor was going to be a woman “for ages,” so he wanted to touch on the psychology of why the Doctor chooses to regenerate in the female form.
“Maybe seeing himself as the [First] Doctor might make him think maybe it’s time to be a bit more progressive,” Moffat says. “Looking at how the First Doctor was, he’s hilariously not progressive.”
Because Moffat is leaving the series along with Capaldi–Broadchurch showrunner Chris Chibnall is taking over for Season 11–he reminisced about some of the famous acting faces that appeared in his Doctor Who episodes, including a pre-Spiderman Andrew Garfield and Olivia Colman before she became a household name in Britain. However, it was An Education and Drive star Carey Mulligan–who appeared in fan-favorite episode, “Blink”– who excited the Doctor Who casting agents the most. They loved her work so much they asked her to become the Doctor’s next companion, but she turned them down flat.
“I don’t think she was much of a fan, or anything,” Moffat says.
The Doctor Who Christmas special airs on Dec. 25 on BBC in the United Kingdom and BBC America in the United States. Doctor Who Season 11, starring Jodie Whittaker, will air on BBC and BBC America in the fall of 2018. No official release date has been announced.