The Daleks’ Doctor Who return was inspired by a Jodie Whittaker photo

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“Well, we knew we wanted something big for the end of series special, and knowing that we would have no old monsters in the series was really a build-up for the special,” Chibnall told the crowd at a special Q and A for the New Year’s Day episode.

“When you see the Dalek, it’s hopefully exciting, it feels rare, and fresh, and thrilling. And also the first encounter for Jodie with that iconic monster. We knew we wanted to do that as the kind of climax of the series.”

But apparently, the real inspiration for the tinpot terrors’ return came from Whittaker herself, specifically a photo she ended up taking during her very first day on the Doctor Who set when she was filming the 2017 Christmas special regeneration with former Doctor Peter Capaldi.

“You remember when we shot the regeneration?” Whittaker asked Chibnall. “I was like a kid in a toyshop walking around the studio having never been there.

“And in the props store is a Dalek. And someone took a picture of me, I had a cup of tea and I was pretending like we were having a chat. Hilarious.

“You texted me the picture," recalled Chibnall. "It was her and a Dalek, her with a cuppa, in a mug like this, and the picture said ‘me and my mate,” .

“And I thought ‘Oh yeah, OK, that’s just irresistible.”

Unable to shake the image, Chibnall decided that Whittaker’s first run had to end with a Dalek story, a parallel to how her own experience had begun with “meeting” the Dalek on set.

“When we came into work and you decided to share with us what we were doing, you’d said that that had been the beginning,” Whittaker said. “And so it felt like the right end I suppose, for this season.”

“It's exciting, and I think for Whovians, or NuWhovians, this moment is as epic for you guys as it is for us,” she added later.

“Because for us to be the first time for some fans that they encounter this particular moment of the history of the show, and for other fans like old Brad [Walsh] that have been with it since the black and white days, this episode is a celebration of old and new.”

“My mum and dad bought me a toy Dalek when I was a kid,” added Whittaker’s co-star Walsh, who plays Graham in the series.

“So to be a part of this show, and to see that – that is one of the best things I've seen in a long, long, long while. I thoroughly enjoyed it. So to end this journey, for me, on that, is unbelievable.

“I'm thrilled to be part of that – it's awe-inspiring, it really is. It's like watching a movie.”

And to think it all started with an old prop in a back room in Cardiff. Very Doctor Who.

Doctor Who returns to BBC1 in 2020