Doctor Who star Jenna Coleman has said that filming Matt Smith's final scenes as the Doctor was an emotional experience.
Smith, 31, makes his farewell as the Doctor in the Christmas Day episode, when Peter Capaldi, 55, will take over the role.
Coleman, 27, told the Radio Times: “It was incredibly emotional - I knew it was going to be difficult but just how emotional I found the process really took me by surprise.
“It doesn't really quite feel like it's over yet, but Peter Capaldi certainly makes an entrance!”
She told the magazine: “I became attached to Matt - it's such a strange relationship because it really is just the two of you.
“You spend every day running together and saving the world and each other's lives... And there's no other way to describe it other than: he's my Doctor.”
Coleman said that she had not yet received the script featuring Capaldi as the new Time Lord.
“I know the first script is moments away from reaching my hand so I'm looking forward to that, but I haven't read anything for the next series yet, so it doesn't feel like I'm two-timing Matt for now,” she told the magazine.
“It's such a double-act and a partnership. With Peter, we're a team and we've been out for lunch together, getting to know each other. It'll be great.”
Doctor Who boss Steven Moffat said that some fundamental Doctor Who myths and stories will be turned on their head or re-imagined in the Christmas special.
“We'll find out that Matt Smith is actually the 13th Doctor - although everyone knows that the Doctor can only regenerate 12 times,” he said.
“That 12-times limit is a central part of Doctor Who mythology - and science fiction is all about the rules, right? So if the Doctor can never change again, what's Peter Capaldi doing in the Christmas special?”
Smith said of Capaldi: “We hung out a bit - he's really good. It's the perfect end for me and the perfect entrance for him.”