Series 12 of Doctor Who was a season of big surprises: the return of The Master (Sacha Dawan), the return of the Judoon, the return of Captain Jack Harkness (John Barrowman), and biggest of all, the reveal of a hitherto unknown Doctor, played by Jo Martin before the revelation of the Timeless Child. It turns out the Fugitive Doctor was created on the fly.
You'd think it was all planned in advance, that showrunner Chris Chibnall had it all figured out, but no. It turns out the Fugitive Doctor was pretty much created on the fly during the writing of the 5th episode with playwright Vinay Patel.
"I think particularly because we had the Master at the start, people thought all our twists were done," showrunner Chris Chibnall exclusively told Radio Times. "And you never do an episode five twist… I don't know where we'll do it again next time!
"And it's all credit to Jo Martin – just an extraordinary performance."
"We had a story, and Vinay and I were talking about a story… and then I just called him up one day and said 'you know this story…what if that's the Doctor?'" Chibnall said. "And he sort of sat and looked at me like 'what?' – so he was the first person to know. And the moment we started talking about it, and we worked really closely together on it in a really great way, it was irresistible."
It was then that Chibnall's plotting brain began to move the pieces together to set up for the rst of the season.
"It was something that came about in conversations," he added. "I was thinking more towards the finale, and then it became… well, there are some thoughts that once you have them, they become irresistible."
What followed was a script that set up the return of the Judoon – and the surprise return of Captain Jack – to cover up for the big surprise in the episode.
"It was also part of the reason of bringing the Judoon in, is they were a great sort of wonderful misdirect," Chibnall admitted. "OK, the thing you're going to be obsessed with in that episode and everybody's talking about because we're doing location shoots is the Judoon.
"Whereas actually, it's the second half that's going to make people lose their minds."
However, Chibnall still hasn't figured out whether or when the Fugitive Doctor will show up again.
"I don't know, is the honest answer," Chibnall told us. "It hasn't happened yet. But the way she's been accepted and the way she's handled it is just beyond our wildest dreams. She's such an exceptional person and actress. Just wonderful, from the moment she came in, the first readthrough…I can't say enough brilliant things about Jo."
Given the excitement of the fans for the Fugitive Doctor, there are loads of possibilities. Not just another crossover, but also standalone episodes featuring her, or even having her replace Jodie Whittaker when she leaves. You never know. Alas, neither does Chibnall right now.