Doctor Who spoilers follow.
A few weeks after Doctor Who shocked fans with an unexpected regeneration, details of how that David Tennant scene came about have been revealed.
Taking over from Jodie Whittaker's Thirteen, the actor, who has previously played Ten, is back as the Time Lord. 'The Power of the Doctor' director Jamie Magnus Stone has weighed in how Tennant's sequence happened, and why he wasn't behind the camera.
While Stone was in Australia, it was Rachel Talalay – who had previously directed a few episodes of Doctor Who season 8 and 9 – who filmed the scene with Tennant.
Related: Doctor Who's Jodie Whittaker reacts to Doctor reunion scene
Doctor Who Magazine shared that Whittaker's regeneration scene was shot in October last year, while Tennant's occurred seven months later "on a similar, slightly smaller green screen just up the road at Roath Lock Studios".
"I can't imagine anyone better," Stone said of Talalay. "I'm an enormous fan of Rachel's episodes. I think she's the best director Doctor Who has ever had."
For her part, Talalay (who'll be back for the 60th anniversary next year) said she is "lucky" to get to direct the show again.
Related: Doctor Who's final Jodie Whittaker episode fails the Doctor AND Yaz
"I am so lucky I get to do this. That I get to re-regenerate David Tennant is phenomenal. I was already incredibly interested in returning," she said.
"Just the fact that Russell [T Davies] was coming back was enough. When I was told it was David too, that took me to a whole other level."
Doctor Who returns in 2023 on BBC One in the UK and Disney+ elsewhere. Meanwhile, in the US, the show airs on BBC America, with series 1-12 available on HBO Max. Classic Doctor Who streams on BritBox in the UK.