Steven Moffat on Why ‘Doctor Who’ and Santa Claus Make Sense

If there’s one thing showrunner Steven Moffat wants fans to know about this year’s Doctor Who Christmas episode, it’s that it will be appropriately festive — as you might expect from a show that brings Peter Capaldi’s Time Lord face to face with Santa Claus for the first time.

“I do think a Christmas episode has to be Christmassy,” Moffat told reporters during a conference call to promote the Dec. 25 episode — fittingly titled “Last Christmas.” “I don’t think there’s any point in pretending than an average episode would pass muster on Christmas Day, it wouldn’t …You have to cut through an even louder living room than normal with your story.”

The episode is the 10th holiday special for the show since it was revived by Russell T. Davies and the BBC in early 2005, and for Moffat, this means that the lead character has finally “earned the right to go toe-to-toe with Santa,” an idea he believes makes particular sense to the show’s younger viewers.

”It’s one of those ideas that, when you have it, you think ‘Why didn’t it happen before now? Why haven’t we seen them in a buddy movie before now?’ ” he said. “They belong together, especially in the hearts of the younger part of our audience, Doctor Who and Santa Claus and Robin Hood all live in the same place.” (Nick Frost plays Santa, and Moffat made light of the perfect casting, name-wise: “Nicholas Frost! It’s a name Santa would choose as a nom de plume,” he said. “It’s much better than Kris Kringle.”)

The team-up of the characters makes particular sense, Moffat said, because Doctor Who “isn’t like other sci-fi shows, because it’s kind of more magical. It’s a big-hearted, optimistic show — admittedly one with monsters that want to commit genocide — but it’s a big-hearted, optimistic show that features, at its core, the science fiction equivalent of Santa Claus.”

Despite the optimism and magic at the heart of the episode, “Last Christmas” also picks up on the downbeat climax of the show’s last season, which saw the Doctor and Clara (Jenna-Louise Coleman) part ways after the death of her boyfriend, Danny.

“We’re not ignoring it,” Moffat says of the separation. “As it ended, they parted forever having lied to each other, and that is where we find them again, we don’t just ignore it because it’s Christmas. It very much engages with that storyline — although, at first, you might think we’re ignoring it, but we’re really not.”

The ability to move from the heartbreak of one of the show’s leads to… well, Santa, is one of the strengths of the show, Moffat believes. “If you do something incredibly dark, where another show would just have another episode of sadness and rain, [Doctor Who] just turns it right around and does something outrageous,” he explained. “When Santa walked onto the TARDIS, it was like saying, ‘Did you forget you were watching Doctor Who?’”

Considering Moffat had earlier described the Doctor as the science fiction version of Father Christmas, it came as no surprise that he was asked whether or not Santa would make a good Time Lord. His answer was simple: “Watch on Christmas Day and find out.”

Doctor Who: Last Christmas airs Dec. 25 at 9 p.m. on BBC America.