Nicola Coughlan says this year’s Doctor Who Christmas special, Joy to the World, is “the perfect family show because it’s funny, it’s heartfelt, and it’s adventurous”.

The Derry Girls star plays the titular Joy, a stand-in companion to Ncuti Gatwa’s Fifteenth Doctor after Ruby Sunday’s (Millie Gibson) exit in Empire of Death. But while Nicola says she’s not watched a lot of the series before, it sounds like she fully embraced it…

How did this role come about?

My agent rang me and said that Russell T Davies wants to talk to you, and that is a very exciting call to get, so of course I said “okay” and he said “come up to Cardiff, come and do Doctor Who”. I had to say to Russell, I don’t know too much about all of this but I would love to come and do it. I’m such a big fan of Ncuti, he is a once-in-a-generation talent, and the thought of getting to act opposite him made this a very easy yes for me.

How does it feel to be part of the “Whoniverse” and more specifically, a Doctor Who Christmas special?

It’s a huge honour. It’s such an institution, so to be part of it at all is such a brilliant thing. I know how important the Christmas special is to people. It’s the kind of thing where the whole family will sit down at Christmas, even if they aren’t regular viewers. Alex Pillai, who directed the episode, is such a huge Whovian and told us stories about him and his family watching it in the ’70s. If I get to be part of that new memory for people, it’s a big honour.

What can you tell us about the character of Joy?

Joy is someone that comes across very shy and retiring when you first meet her. She’s somebody who never wants to cause a fuss, and it’s a bit strange at the beginning because you see her checking into this hotel on her own on Christmas Eve and you don’t really know what her story is going to be at this stage. It seems quite unusual, and then you realise that she’s somebody who is hiding a lot of pain and has a lot of struggle in her life, but is not really facing it. When she meets the Doctor, he’s not somebody who is going to let her rest on her laurels and he really takes her through it. It’s a big adventure.

How did you react when reading the script?

I just loved it so much, aside from being completely confused by the timeline at first when marking up my scripts! You also often film things out of sequence so there’s already elements of time travel in filming any show, and then you put in the actual Doctor Who time travel and you’re thinking “oh my God”. I just thought that this is really fun, and it’s so different to anything I’ve ever done before. I was super excited to do the stunts, which are a thing that I didn’t know I would enjoy. The chance to do those was brilliant.

How did it feel to be acting with lots of special effects and actors in alien costumes/prosthetics?

It was amazing because it felt like “oh, we really are in Doctor Who”. It’s not just a bunch of humans. When that door opens and a Silurian walks in, you know you’re in the Whoniverse. I was thinking, “here we go!”

What do you think makes Doctor Who so special, especially at Christmas?

I think it’s the perfect family show, because it’s funny, it’s heartfelt, and it’s adventurous. It’s just pure excitement, and joy, and I think this episode in particular has a really beautiful message underpinning it which is all down to Steven Moffat’s writing. It’s a perfect cocktail of all those things.

Where will you be watching the episode on Christmas Day?

I’ll be home in Ireland with my family, so I’ll be watching and very much hoping to impress my teenage nephew. We sat down and watched the Christmas special last year all together, thinking “this is going to be me next year!”.

Describe the dynamic between Joy and the Doctor?

I think the dynamic between them is very, sort of, he pushes her and she tries to remain a brick wall. A very polite and sweet brick wall, but he knows that in order to get to where needs to be with Joy, he needs to push her to uncomfortable places. It’s a very interesting dynamic because she wants to remain polite and unaffected but the Doctor is not going to let her do that.

How was it working with Ncuti Gatwa?

Working with Ncuti was honestly wonderful. He is such an incredible talent, and you never know what it’s going to be like when you watch somebody on screen and then get to work opposite them, but he’s electric and talented in person too, if not more so. He has a real magic to him, and I think he’s a perfect Doctor.

Do you have any standout memories from working with Ncuti on set?

I really loved the prehistoric room of the Time Hotel. That was very fun, because it was extremely stunt heavy. The two of us rigged up together, sliding all over the place, that was really brilliant. I loved filming those scenes.

If you had access to the Time Hotel, where would you go first?

I feel like I would go to a Gatsby-esque party in the 1920s/30s. Lots of champagne and dancing, that would be very fun.

Joy to the World will be broadcast on BBC1 on Christmas Day, at 5:10pm, and will be available to stream on Disney+ outside the UK.