Doctor Who Christmas special will solve "longest-standing mystery"

"Doctor Who is just very Christmassy," he explains now, ahead of current Time Lord Ncuti Gatwa’s second festive adventure. "It feels like family, it feels entertaining. It’s got comedy and tragedy."

"It absolutely is Christmassy," agrees Moffat, who was asked by Davies to write this year’s special. "Doctor Who occupies the same space in a child’s mind as Santa Claus. You know, he’s grumpy to adults, but loves kids. The Doctor and Santa have always belonged together."

Davies has written six Who Christmas specials to date; Moffat’s figure including this new episode stretches to nine. But that doesn’t mean he has become any less ambitious in his festive scripts.

"This year, the Doctor will tell you the answer to that question you’ve been asking since you were a small child," Moffat proclaims. "The solution to the longest-standing mystery in not merely the Doctor Who universe, but the universe as a whole. Watch on Christmas Day!"

Exactly what that mystery is remains, well, a mystery. Though we do know this episode – titled Joy to the World – is set in a "time hotel", which allows the Doctor to visit Everest Base Camp in the 1950s, the Orient Express, the Second World War, the year 4202 and the distant past. And as ever, he won’t be investigating alone.

With Millie Gibson’s Ruby Sunday having departed earlier this year, Bridgerton actor (and Gatwa’s Barbie co-star) Nicola Coughlan steps into Christmas as the eponymous Joy, before a new full-time companion starts next year.

In RT’s exclusive preview picture, we see the duo in a dingy B&B, confronted by an ominous briefcase clamped to Joy’s wrist – the very item the Doctor is chasing through history. "I was like, it’s set in a hotel, so the baddie has to be baggage!" laughs Moffat.

"You’ve got Ncuti’s Doctor, discovering who he is without a companion," adds Davies. “He’s on a whole new quest to find himself… It’s gorgeous, it’s properly heartbreaking and fun. And there’s a dinosaur. What more do you want?"

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Doctor Who will return to BBC One and BBC iPlayer this Christmas. Previous seasons are available to stream on BBC iPlayer.

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