This year’s Doctor Who Christmas special is taking fans right back to the earliest days of the sci-fi series, with the very first incarnation of the Doctor (played by David Bradley in lieu of original actor William Hartnell, who died in 1975) returning to team up with his later self.
And the return of the First Doctor more than half a century since his regeneration offered all sorts of storytelling opportunities to episode writer (and departing showrunner) Steven Moffat, including the chance to fill in a couple of old plot holes from Hartnell’s final episodes.
Why, for example, did Hartnell’s clothes change when he regenerated into Second Doctor Patrick Troughton? And what was the cause of the First Doctor’s frailty throughout the episode (actually due to Hartnell’s own illness)? And why did he even regenerate at all?
So when it came to writing the story, Moffat toyed with solving some of these lingering mysteries – but then decided it might be a BIT too nerdy, even for him.
“I nearly went as ludicrously as explaining the clothes change,” Moffat admitted on the set of Twice Upon a Time when RadioTimes.com visited shooting earlier this year.
“But then I just thought no, people are paying their license fees for other reasons than this. So that one’s still out there.
And when it came to Hartnell’s frailty and largely unexplained regeneration, Moffat decided to stick to the official party line…
“There is an explanation in there, it just says he’s getting old, he says his body’s wearing a bit thin – so that’s there,” Moffat said. “He also has a line about maybe it’s some external influence, which these many years later no one has picked up on. I haven’t [either].
“He’s already regenerating as we meet him. So it’s not me, we didn’t do that.”
More generally, the cast and behind-the-scenes team were keen to emphasise that despite the central role of the First Doctor, the special wasn’t just for die-hard fans who’d been watching since the 1960s.
“It’s not just a fan goodbye,” regular series writer and actor Mark Gatiss, who plays The Captain in Twice Upon a Time, told us. “These are all little trimmings.
“It plays very well as a sort of standalone, even if you’ve not seen the full series – or indeed if you’ve not seen anything else of Doctor Who either,” added Pearl Mackie, making her final appearance as companion Bill Potts in the episode.
“Which is nice! There’s jokes in it, there’s fun for kids, and there’s fun for adults. I think it’s going to be great.”
In other words, then, it’s an episode that pays tribute for the past, while not going full Whovian and spending the full hour explaining away plot inconsistencies from the 1960s. Probably the right mix for a Christmas special.
Doctor Who: Twice Upon a Time airs on Christmas Day (Monday 25th December) at 5.30pm