Sinead Keenan’s Nina begun her Being Human journey antagonistically inclined towards werewolf George – and became even more annoyed after he infected her with the werewolf curse. But in the third season of the BBC Three show, their relationship has become one of the core elements of the series, with Nina’s pregnancy one of the central storylines. Paul Simpson spoke to her on set as she filmed the final episodes…

What was your reaction when you found out Nina was going to get pregnant?

I was delighted in one sense; in another, I thought, “Now what does that mean? Will I have the baby? Will it be a baby? Will it be a pup? Will it be normal? Will it not?”

We have to sort out whether the werewolf thing is like puberty: does it hit you when you’re 16, if you’re not scratched and all that malarkey? I knew there would be a lot of fun to be had. It’s been a lot of hard work, but mainly fun.

How much have Nina’s experiences changed her?

They’ve changed her in the obvious way in that she’s now definitely a bona fide 100 per cent werewolf. She’s been through that a few times; she’s got her own routine when the full moon comes round.

I think she’s softened a little: she’s always had that hard exterior, but now any time when anyone gets hurt in the house, little Nina’s first aid kit comes out. I’ve just done a scene with Robson [Green] sorting out his leg – I’m good at leg cuts now. I can sort out anyone!

Did you get much input into what you’d like to see her do, or not do?

Not really. We’ve got Toby Whithouse at the helm, and he always gives everyone great storylines. It’s not something I ever worry about not having any input in because you know you’re going to get something great.

He’s open to suggestion: if there’s a line I don’t quite understand, or I don’t think she’d say it that way, it’s not written in stone that it’s written that way. You have to put very little in, because it’s all so brilliant as is.

There are a load more werewolves this season with Robson Green and Michael Socha around: are you pleased you’re not the only one other than Russell who has to go through the process?

Take my kit off, and get up at silly o’clock? Yes, it’s great. It lightens the load, because for budgetary reasons we can’t all transform at the same time – at least on filming days it can’t all happen at the same time.

Are you and Russell still played by the same actor when you become a werewolf?

Yes, the same person in the same suit. Robson and Michael’s prosthetic looks quite different to ours. I think the thinking on it was that every wolf family has a different look, as every family does visually. Their prosthetics are a little more feral-looking than ours, at least that’s what I think.

What has the move to Barry Island been like?

We were very sad to see Bristol go; we had a lovely time filming there, and the architecture of Bristol is perfect for the show as well. It became part of the show, the city itself.

Having said that, we’ve had a great time in Cardiff. The weather has been ridiculously nice; apparently, it rains a lot in Cardiff, but we haven’t seen much evidence of that, until fairly late on in the summer when it did lash a couple of days when we were in the caravan [in episode six].

What do you think of the new set, Honolulu Heights?

I think it’s amazing. When you start doing pre-production and the read through, there’s a model of the set and those who’ve seen the sets are saying they’re amazing… but you have no concept until you see them. They’re huge – they’re virtually to scale, which sets very rarely are. I think it’s brilliant: there are four floors with the cellar and the attic. Myself and George have a lovely kitsch romantic bedroom: we got the bridal suite!

It is a bit sad not being in the old house: it became iconic, if something can be iconic after two series. But maybe this will become iconic.

What’s most challenging about playing her now?

To be honest, the transformations are, just because you’re up at silly o’clock, and for want of a better phrase, you’re on all fours pretending to be a dog for a day… which for anyone, particularly a woman, is just a little bit embarrassing.

In TV you get a lot of two-dimensional characters, but I’ve been lucky: I get the comedy, the feisty moments, the really scary times. I’ve had a little buffet, a pick-a-mix. You do see a lot more of her this year.

What would you think of Nina if you met her?

I don’t know if I would like her. Without wanting to sound really wanky talking about her in the third person, if she was a real person, I think she’d be very hard to get to know initially. A cold-shouldery, take no prisoners, take no bullshit kind of person. But once you got to know her, if you got that far, she’d be perfectly lovely. I think she has a very protective exterior.

What do you think it is about the show that has struck a chord with the ardent fans and the general audience?

I honestly think the whole thing about a vampire, a werewolf, a ghost is incidental. At the heart of it is a group of friends who are trying to get on in life. The scripts are great. I know some people thought it was a bit too dark last year and they wanted to bring the comedy back. I think this year is a perfect pitch between the two: there’s an equal amount. We’ve laughed and cried within the space of seconds.

It’s not just a vampire show, a werewolf show, a ghost show. And taking myself out of the equation, I think the cast is brilliant, and we have a lot of fun.

Being Human airs on Sunday nights (BBC Three).