Last night saw the press preview for the Doctor Who Christmas special, Twice Upon A Time, and once the episode was over, Jo Whiley hosted a Q&A with Mark Gatiss, Steven Moffat, David Bradley and Pearl Mackie.

Lots of things were discussed, as you’d expect. But these are the non-spoilery things that were said.

• Steven Moffat admitted he reworked a key speech in Twice Upon A Time off the back of a question he was asked at the first screening of the series 10 opener, The Pilot. The question was put to him by a young fan, and Moffat admitted that it sat in his head, and as such, he altered a moment in the episode in response to it. The young fan, George, was in attendance to hear how he’d changed the episode. To tell more would be to spoil things, but it was a really lovely revelation.
• The regeneration of Peter Capaldi to Jodie Whittaker wasn’t seen in full at the press preview. This was at the request of Chris Chibnall, the incoming showrunner. All previews of Twice Upon A Time will have the final scene curtailed, so that Whittaker’s entrance will only be shown in full on Christmas Day, when the episode airs. Chibnall wasn’t in attendance, incidentally, giving that filming of Doctor Who series 11 is ongoing. Peter Capaldi wasn’t there either, sending a message instead.
• Pearl Mackie admitted that she’s taken a key to the TARDIS and kept it as a souvenir. Moffat joked that someone in Cardiff is trying to open a TARDIS, but can’t…
• David Bradley is really very chuffed to be having a figurine/action figure made of his Doctor, that’ll be released soon.
• He wore the same hat he used in An Adventure In Space And Time, at his own insistence.
• Steven Moffat was asked the favourite of the episodes he’s done. He argued that he didn’t really have favourites, but eventually singled out Vincent & The Doctor and Day Of The Doctor, whilst also adding that he’d rewatched Robot Of Sherwood the other day and laughed himself to bits watching it.
• Pearl Mackie described being in the midst of Doctor Who as a “whirlwind”, adding that she wasn’t sure she’d fully feel the impact of it for a while yet. She’s loved her time on the show.
• Former Doctor Who companions, Mackie added, swap stories of the BBC canteen.
• Finally, Steven Moffat ended with a passionate justification for why Doctor Who is the greatest TV show of all, arguing that it’s inspired people – just by watching it – to become scientists, writers, directors, actors and a whole lot more. His speech brought the house down.

Twice Upon A Time airs on Christmas Day at 5.30pm. It’s excellent.