The Christmas Special has been a yearly tradition for Doctor Who since the show was relaunched in 2005. Since then, the BBC has aired an episode on December 25th every year and this year is no different, despite Season 10 not arriving on our screens until 2017. In 2015, following on from the end of Season 9, the Doctor (played by Peter Capaldi) was without a companion after the departure of Clara Oswald (Jenna Coleman). He was alone in the TARDIS for the last two episodes of Season 9, but showrunner Steven Moffat was filled with festive spirit and allowed the Doctor a companion for the Christmas Special in the form of his wife, River Song.

'The Husbands of River Song' was well-received, and pulled the most viewers of any season 9 episode, as is the regular pattern with Christmas Specials (though Christmas Specials are generally viewed as standalone episodes and not part of a season). So it's no surprise that the BBC and Moffat still want to hold with tradition this year, but right now, the Doctor is still flying solo.

Though his newest companion, Bill (played by newcomer Pearl Mackie) has already been introduced, speaking to Doctor Who Magazine, Moffatt has confirmed that her debut will be at the start of Season 10 in 2017, and the Doctor will have a different guest companion for the Christmas Special:

"We’ll introduce [Bill] in the first episode of 2017, and she’ll run through that series. She’ll not be in Christmas [2016], because that would blow the series launch … So there’ll be somebody else – a different, guest companion – this Christmas, like how River Song played the companion role in last year’s Special."

Of course, this now leads everyone to wonder who might join Capaldi in the TARDIS. Based on Moffat's words, it seems as though we are unlikely to see the festive return of River Song (Alex Kingston), but the possibility for another previously introduced character is certainly worth considering. Matt Lucas is confirmed to be reprising his role as Nardole for season 10; might the Christmas special be a good time to re-introduce his character? Given that the specials usually have a lighter, more comedic tone than the seasons, the prospect of the Doctor and Nardole sharing an adventure together is an amusing one, to say the least.

Doctor Who Christmas special - Peter Capaldi and Alex Kingston
The Doctor (Peter Capaldi) and River Song (Alex Kingston) in 'The Husbands of River Song'

Then there's the possibility of Maisie Williams returning as Ashildr/ Me. Though the actress herself has said she won't be working on the show again, that was in reference to her becoming the Doctor's new companion. Since a guest appearance for one episode is less of a time commitment, Williams could well be persuaded, especially since Season 9 made much of the connection between the Doctor and her character. Another, perhaps more remote chance, is that Missy (Michelle Gomez) might somehow find herself embroiled in some kind of trouble with the Doctor, or needing his help in some way, causing the two to travel together.

Whatever the outcome, we can be sure the Christmas Special will be a fun break from the heaviness of Season 9, and a good prelude to Season 10, which Moffat teases as being very different. "I want it to feel like episode 1 of a brand new show," he told Doctor Who Magazine (via Cultbox). "I want to leave just as it's all beginning." He added:

"First episodes are tough, and I feel as though I slightly fumbled it last year by not having a ‘new thing’ in ‘The Magician’s Apprentice.’ It was the same Doctor, same companion … You want to persuade people to tune in because a brand new thing is happening."

Doctor Who - Peter Capaldi and Pearl Mackie

Doctor Who Season 10 will be Moffat's last at the helm, since he is leaving after eight years as showrunner. Broadchurch showrunner and previous Doctor Who writer Chris Chibnall will take over from 2018, and Moffat admitted that though he's enjoyed his time on the show, he only decided to stay past his initial three years, because that third year was so tough.

"Well, there was a long time when I thought I’d only do three years. That was the absolute plan … But I didn’t enjoy my third year as much. It was a bit miserable … The workload was just insane. I wasn’t coping as well. No-one else’s fault, all mine. The 50th was looming, and I didn’t know if we could make it work. It was a tough, tough time. My darkest hour on Who was that. […]

"Matt [Smith], who was a friend and ally, was leaving – I couldn’t get him to stay. It felt like everything was blowing up around me. I was staggering into the 50th, with no Doctors contracted to appear in it, battered with endless hate mail about how I hadn’t got William Hartnell back … and Sherlock Series Three at the same time … I was pretty miserable by the end of it, and I couldn’t bear to let that be the end."

Though Moffat has undoubtedly served Doctor Who well, it does feel as though now is the right time for him to move on, and it will be interesting to see exactly how Season 10 all pans out, especially if, as hinted, there are some big shake-ups ahead. However, surely the biggest changes will come after Moffat's departure, maybe even starting with a new Doctor?

NEXT: Steven Moffat on Casting the Doctor Who Season 10 Companion

Doctor Who Christmas Special will air on BBC1 and BBC America over the holiday season. Season 10 will arrive in 2017.

Source: Doctor Who Magazine (via Cultbox)