(Kiri will air on Channel 4 and Hulu. It will be on Channel 4 from Wednesday January 10, 2018 at 9pm)

Kiri: Interview with Lia Williams who plays Alice Warner

Your new drama is Kiri – could you explain a little bit about the show and who you play?

I play Alice. I’m in a pretty tired marriage, and I have a teenage son. In order to keep the marriage and the family alive and functioning Alice and her husband Jim foster a little girl, Kiri, with a view to adopting her. She’s a very beautiful little girl, who Alice, throws her life into and then a terrible tragedy occurs, which kicks off a whole train of events, which makes all of the characters in the piece question who they are and what they want in their lives. It’s particularly true of Alice. She goes on this sort of incredible journey. It’s probably one of the finest-written TV roles I’ve ever played, in the sense that it’s properly character driven, and Jack Thorne has quite magnificently got inside her head and taken her on this journey. For me, Alice is kind of an anti-hero. She’s really flawed, she does all sorts of really wrong things, but hopefully, what I was trying to achieve with it, was that you really care about her. We’re all flawed, and we all do loads of really wrong things. And often in TV drama, characters are stereotypes, but Alice is fully human, as are all the characters in this, in that they have good and bad and everything in between. Because we are thrown into an extreme situation through a tragedy at the beginning of the story, these characters are sort of pushed to an extreme of themselves. 

My next question was going to be “what attracted you to the role?” but I take it the answer was the writing?

I was blown away by the script. It was so exciting to read a part for an older woman who is fully alive and complex and wonderful and terrible all at the same time. And sexy. She’s got so many things going on, and of course those are very exciting for an actor to play. Jack has obviously written a very good story, but it’s his characters that lit me up, because they’re all like this – they’ve all got so many exciting aspects to them.

Were you already a fan of Jack’s work?

Yeah, absolutely. I think he’s kind of the man of the moment, isn’t he? And he’s a great theatre writer, and I’m a big theatre actor, so I knew of his work through theatre, really, more than television. 

As well as working with one of the finest writers around, you’re acting alongside Sarah Lancashire. How did you find that experience?

Really one of the best I’ve ever had. She’s exceptional. She’s very quietly brilliant. She doesn’t announce herself, she just works really hard. I was kind of knocked out by her generosity. And her versatility. I think she’s got amazing comic timing, but she can play the big tragic stuff as well. She’s really impressive, and a really lovely woman as well, which is kind of a rare combination. 

The other characters are very strong. You have a lot of scenes with Steven Mackintosh and Finn Bennett, who play your husband and son – how did you find working with them?

Absolutely brilliant. And we felt like a family by the end of the shoot. There was a very, very close feeling, which was generated by Euros [director Euros Lyn]. I think he’s brilliant – I think he’s the best television director I’ve ever worked with. His casting was such that we did actually feel like we were a family. I had worked with Steve before, so there as a kind of language that we already had between us. And I just adored Finn. They’re all interesting – the relationship I have with my husband is brilliant – it’s kind of Bergmanesque, really – and then I’ve got this really complicated relationship with my son, which is slightly oedipal. There’s a kind of confusion going on there with him. And then Lucian Msamati and Wunmi Mosaku are both brilliant as well. All of that creates such a buzz, you just love going in to work. 

Did you do anything in the way of research, or is it all there in Jack’s script, so you don’t have to?

We very fortunately had a week’s rehearsal, which you don’t normally have in TV. And during that time, we had basic knowledge of what fostering entails, and some basic research. But because it was so character-driven, I decided not to make that a focus, I just worked on who she was, rather than anything else.

Are you good at switching off at the end of the day’s filming? Or do you carry it with you?

Well, I’m just about to open in the West End, playing both Elizabeth I and Mary Stuart, in Mary Stuart, with Juliet Stevenson. And at the toss of a coin, live onstage, in front of an audience, the coin decides which role we play that night. It meant we had to learn 1400 lines, and you don’t know which one of two epic women you’re going to play. I suppose what I’m saying to you is that I relish these big, difficult female roles, who have much more to do than just load the washing machine. So, yes, of course that rubs off, but I kind of figure that that’s what I’m here for, so that’s fine. I don’t want to sound over-zealous, but I’m really in love with what I do, and so if a character rubs off on me, that’s okay, and I will go and do my holidays and my yoga, and my son’s teaching me rock climbing, and those sorts of things counter-balance it. 

You played Wallis Simpson in The Crown – an extraordinarily lavish production – and then you’re in a Channel 4 drama. Does it feel like the same profession, when you’ve got such contrasts?

I didn’t really view it like that. I was absolutely bowled over to play Wallis, and my costumes were handmade with cloth sent in from Italy, including gloves and shoes. Every single item of clothing I wore was handmade to fit me. It was just exquisite, the costume designer was a real artist. So you’re working with incredible people at the top of their game, and that’s wonderful. But in terms of comparing it to Channel 4, the directors were both brilliant and wonderful, the scripts were brilliant, and also, Wallis is just an incredibly complicated woman, just like Alice, just like Elizabeth I, just like Mary Stuart. I just feel thrilled that these really amazing, interesting and off-the-wall women are coming at me now. It’s brilliant. So they were both rich experiences.

Kiri airs on Channel 4 and Hulu. It will be on Channel 4 from Wednesday January 10, 2018 at 9pm