This year’s Doctor Who Christmas Special, The Doctor, The Widow and The Wardrobe, is set in wartime Britain and a futuristic forest. War widow Madge Arwell and her children, Lily and Cyril, have been evacuated to a quaint house in the countryside. There they meet a mysterious chap calling himself The Caretaker – in fact, it’s The Doctor! Matt Smith tells What’s On TV more secrets about this ‘very Christmassy’ adventure…

Can you set the scene when widow Madge Arwell and her children turn up at this draughty manor house and meet the Doctor?
“He’s very excited to see Madge and her children and make Christmas wonderful for this family who’ve been through so much. It’s very cosy and Christmassy in this house. It’s quite nice to see children as the central characters in a Christmas special.”

Why does he call himself The Caretaker?
“He just wants to give himself a new name for a while. But he’s ridiculous and they’re like, this isn’t how caretakers behave! He just wants to take care of things but of course The Doctor taking care of things is making the house twirl about in ridiculous ways. It’s the Doctor landing in a normal situation and changing it in a way only he can.”

What happens to the Doctor and the family at Christmas?
“There’s a sort of slow-burning magic to the story and it has a Narnia-esque feel to it – they all get to crawl through this mysterious blue present and into an enchanted forest that looked amazing. They covered this forest in snow. It looks incredible. We covered whole forests in snow. The scale of it is vast and it feels magical. We never see that in this country. It’s never THAT snowy.”

Is there a monster in the forest?
“There is a monster. There is a threat in this magical world, a definite threat. I’ll keep the monster as a surprise. It’s one of our best. The design of it is classic. There are others in the forest, too, who are like forestry workers in these great armoured suits. Their leader is played by comedian Bill Bailey!”

How does he get on with Madge?
“Madge is a plucky feisty mum who is quite clumsy, too, but takes care of things. The Doctor finds out something tragic about her life – and subsequently tries to give her and her children the best Christmas ever – which turns out to be the best Christmas ever in a really dangerous forest! Claire Skinner, who plays her, is great. I’m a big fan of her in Outnumbered.”

What can you reveal about the black space suit he wears at one point?
“At the beginning of the episode the Doctor finds himself in this space suit and he crashes to Earth in it. His helmet’s on backwards and he can’t see to navigate – which is funny, hopefully.”

Do you get a lot of stunts in this episode?
“Oh yes. It’s quite action-adventurey which I like. I’ve done all my own stunts this year – well I’ve done two. There have only been two! There’s a big explosion and I do the jump. And another one involves leaping over something which hopefully will be very funny as I land awkwardly. I really enjoy that. Maybe we’ll see more of an action hero Doctor next season.”

How do you get into a Christmas frame of mind when you start filming it in September?
“The wonderful set does it for you – the snow, the pine trees and the smell of them. I’m so looking forward to Christmas! There have been a few night shoots – they can be tough.”

What were your favourite Christmas memories as a kid?
“I didn’t have Doctor Who as a kid sadly. Boxing Day was always the football in my house. I love Christmas. I can’t wait – family, presents and the rest. The older you get, the more you like buying things for other people. Working so much has meant I haven’t had much time with my family as I have previously, so to have a run of two or three days with them is good.”

Will you watch Doctor Who with your family?
“We will sit down and watch it together. My sister usually gabbles on during the middle of it. My dad will be like sssshhhhh. They like the surprise. I always get a text every Saturday saying they liked each episode.”

Can you tell us anything about next year’s series?
“I think we’ll be filming from February. It’ll be a busy year. I’ve just heard the pitch from Stephen Moffatt. Amazing. Very exciting. I can’t give anything away though.”

Were you sad when you heard Doctor Who Confidential has been axed by BBC3?
“Yeah, really sorry. It’s a pity as I think it’s a show which can reinvent itself year on year and it’s one of the biggest shows on BBC3. But I guess people come in and have new ideas and want to have their own fresh take on it but, hey, some you win, some you lose…”

The Doctor, The Widow and The Wardrobe is on BBC1, Christmas Day at 7pm