An animated episode of Doctor Who was a dream come true for its creators

When Polygon had a chance to video-chat with Doctor Who stars Ncuti Gatwa and Varada Sethu in advance of the new season, there was an experience that leapt out as their favorite: filming the animated sequences for this Saturday’s episode.

Not recording — filming.

“Shooting the animation was very fun,” Gatwa said, “because it was just a different way of working, and we’ve not had that.”

“I think when we first read it,” Sethu added, “we assumed that we’d be doing a voice-over much later on and they were just going to animate it. But no, we had to really shoot it.”

“And they animated to our actions,” Gatwa clarified, “and what we did in the scene. It was cool.”

[Ed. note: This piece contains mild spoilers for the second episode of Doctor Who’s 2025 season.]

The episode — called “Lux” — features guest star Alan Cumming (Schmigadoon!, X2) as the animated antagonist Mr. Ring-a-Ding, a strange character who could have stepped out of any level of Cuphead, modeled after the animation styles of the 1930s. And in one pivotal moment in the story, he traps the Doctor and Belinda inside an animated film as animated characters.

When Polygon asked showrunner Russell T Davies about the process behind Who’s dive into animation, he said that it was always something he’d wanted to do in his career, but had never had the budget for it before.

“It costs a fortune, let’s be absolutely honest,” Davies said over video chat. “It’s a proper skill; it should cost a fortune, because it’s a proper labor of love. And so to be able to do that with Disney Plus was absolutely gorgeous.”

Davies noted that his first job at the BBC was working in graphic design — on the children’s series Why Don’t You? among others. “Cartooning and cartoons is in my blood and bones. If my life had taken a different turn, I would be working graphics and then cartoons in some shape or form.”

Still, Davies said, working with animation was a learning experience. “I’ve been through effects meetings a million times. We had meetings I didn’t know existed with animation, signing off everything — you have to sign off every blink that the character makes, every flex of its hand. Just designing it, and discovering the history of it. Even discovering things like — I remember at some point someone saying, ‘Like classic cartoons of the ’30s and ’40s and ’50s, should he have white gloves?’ But actually, that’s a minstrel’s gloves, and the white gloves are kind of frowned upon now — or it has a different context now, that in our context wouldn’t look good. So you learn things like that. It was fascinating. We learned about the entire history of cartoons.”

Alan Cumming’s performance was recorded in stages, according to Davies: First, a preliminary voice recording so that Gatwa and Sethu would have something to react to on set, and then a second, booth recording of Cumming’s voice and mouth movements, “so the animators and the actor can get to know each other in the middle stage, as it were.” And finally, the animators would add any additional dialogue recording and exclamations that cropped up in the process of animation.

Davies said that he and his team were not experts, and so they were happy to lean on their animation partners for process details. “I think they liked us,” he laughed, “because we said, ‘Ideally, how would you want to do this?’ […] Whatever the animator said would be best, that’s what we did.”

And in the case of the Doctor and Belinda’s brief stint as cartoon characters, that meant filming Gatwa and Sethu in character, so that the animators could work with the actors’ own movements. The results are one of modern Who’s most strange and cinematically metatextual moments, as the show’s heroes strive to literally become more three dimensional and escape the flat plane of the screen.

“It was just an enormous playground,” Davies said, and then corrected himself. “Far more than a playground — a proper professional world of animation. I loved the weeklies with the animators, I loved those meetings. I loved it. It made me very happy.”