Doctor Who showrunner Russell T Davies has revealed the surprising reason Billie Piper returned for the show's latest finale, confirming rumours that it was a last-minute decision.
In an excerpt from his new book, The Queerest of Folk: A Life in Television, the writer explains that Ncuti Gatwa's exit was originally supposed to end with the Doctor's fate left deliberately open-ended because of the uncertainty surrounding the BBC's deal with Disney+.
"We knew Ncuti Gatwa was leaving, so I’d written the climax in which the Doctor, having saved the life of a baby in The Church on Ruby Road, Ncuti’s first episode, now departs by saving the life of a baby because the universe is at stake," Davies writes. "As the third series was in flux, the finale was intended to climax with an open-ended regeneration."
"So we shot that with Ncuti: he smiled and said his last line, and the screen melted into a golden glow," he added. "Except when we edited that together, it looked like the death of the show."
The writer quickly realised that this type of regeneration wasn't going to work. "We said, 'Think of children watching that. It’s like a death. We can’t do that to them.'" With the show effectively stuck in limbo, Davies called a meeting with the production team and came up with an unexpected solution: Billie Piper.
She played Rose Tyler during the revived show's first two seasons, and made a handful of cameo appearances after her initial departure in 2006. Her return—seemingly as the new Doctor—offered a very different way to end Gatwa's time in the TARDIS, and Davies was given the chance to resolve the cliffhanger with a Christmas Special.
"Everyone hates giving bad news. So when it came to announce the end of the Disney deal, the BBC was very keen to announce the existence of a Christmas Special for 2026 at the same time, to confirm its dedication to the show," he recalls. "I pitched it to the BBC, and they loved it. An olde-worlde English village intercut with a huge, mysterious spaceship, an outer-space festival called Winternox, and lots and lots of Daleks, with something very unexpected hidden away."
However, the project ultimately became another casualty of the show's uncertain future. Davies says he didn't even receive a contract to write the special until March 2026, months after its existence had been announced in October 2025. "For the first time in my life," Davies says, "I allowed my name to go on a press release that I actually felt kind of queasy about."
The BBC's decision to put Doctor Who out to tender much sooner than he'd anticipated also allowed Davies and production company Bad Wolf to gracefully step away from the franchise at what he felt was the best possible time. He notes, "I went to the BBC on 6 May 2026 and said: 'I don’t think we should be making this.'"
Still, what happens to Billie Piper's Doctor now? Davies acknowledges that the next Doctor Who creative team will have to address her appearance, but insists it's hardly an insurmountable problem.
"Yes, that leaves us with a Billie puzzle, but c’mon, that’s easy. Doctor Who problems are simple to solve," he muses. "A new production team can either seize hold of that appearance happily, or – and this is more likely – they can explain the event away with exactly seven words. Painless. That’s not a problem, that’s a piece of piss."
And with that, Davies is officially saying goodbye to the Whoniverse. "So that’s my farewell. Goodbye, Whoniverse. God, that was fun! I wouldn’t have missed a single second of it. What a remarkable show," he says in his farewell to the long-running sci-fi series.
You can read the full excerpt at The Guardian.