"You don’t see this job portrayed on TV" – Nicola Walker explains how new BBC divorce drama The Split is breaking new ground

• Neil Morrissey and Alex Jennings join Unforgotten as plot of series three is revealed
• ITV confirms Unforgotten will return for a third series
• Stay up to date with the RadioTimes.com newsletter

“There is a deep, deep sadness running through these stories,” Walker says. “And when you’re doing stuff that’s really dark, you can stay in that place. So, I’d be really serious all the time if it wasn’t for Sanjeev. It’s his fault if I’m not always serious.” Bhaskar feigns offence. “My fault? I’d say it’s my credit,” he says. “There are scenes in Unforgotten that are so intense, horrible and tragic that you have to find a way to relate to each other as human beings again.”

We are in a high-ceilinged drawing room in a dilapidated former country house in Buckinghamshire, where they’re shooting series three. As well as the pathology lab, the building houses the cluttered incident room where the cold case team consider pictures of disinterred bodies. Exteriors are shot in the grounds, where their co-star Neil Morrissey is presently wandering.

The drama attracts a high-profile supporting cast. As well as Morrissey, Trevor Eve, Bernard Hill, Gemma Jones, Wendy Craig, Douglas Hodge and Mark Bonnar have all appeared, and Bhaskar and Walker speak with awe of Tom Courtenay’s Bafta-winning performance as Eric Slater in series one. “It’s the only time I’ve seen the crew all break into a spontaneous round of applause,” says Walker.

Actors like Courtenay come, in part, for the quality of Unforgotten creator Chris Lang’s writing; scripts that slip beyond the confines of procedural to address the psychological state of the nation. “The first season asked if a crime is any less a crime because it happened a long time ago,” says Walker. “And Cassie felt absolutely not. The second ruminated on the concept of justice. When you go back and look at how the people who committed a crime got to that point, when you see that they suffered horrific abuse, then justice gets a bit more complicated.”

She has a theory that, thanks in part to the Jimmy Savile and Rolf Harris revelations, we live in a time when the past, and television’s past especially, is untrustworthy. The British were ready for a show that seemed to redeem the sins of the 70s and 80s. “We grew up with Jimmy Savile on our televisions,” she says. “Chris was fascinated by what it was like for the people who knew someone like that – people who loved him and believed the lies that he told. What was it like when they found out there was this whole other person?”

Walker had been wondering the same things herself. “It felt like all the people we grew up seeing on TV and were told we should respect were falling like dominoes,” she says. “It was a strange period; every time I read the newspaper there was someone else. I’d been told as a kid they were talented, important people, but they were living a lie. A lot of those men from the 70s had this completely different life.”

Now the USA is also being obliged to face the misdemeanours of its entertainment industry and audiences are picking up on Unforgotten. “The first two series are going out in America,” says Bhaskar. “People there are tweeting me about it, and they’re caught up in these stories. I think it has a dramatic weight that other whodunnits may not carry to the same degree. It’s because our characters aren’t heroic… we don’t save the day.”

Much of the drama’s appeal rests in the interactions between the two leads. Stuart is Khan’s senior, but there is more going on than the usual detective and sidekick relationship. Morse’s private life was a mystery to Lewis, and vice versa, but Stuart and Khan know each other. “I haven’t really seen it before in a cop show where you’ve got a man and a woman who really, really care about each other, respect each other and look out for each other. They provide a level of intimacy for each other they don’t have at home…”

Walker, 48, who is married to the actor Barnaby Kay with whom she has a son, says she has always been lucky with her co-stars. “Just think of Last Tango in Halifax. You walk on and it’s Derek Jacobi and Annie Reid and Sarah Lancashire. You’re in a really good place.”

Born in east London and a graduate of Cambridge University’s Footlights, Walker is an acclaimed stage actor, with an Olivier Award in 2013 for her performance as the mother, Judy, in The Curious Incident of the Dog in the Night-Time. Bhaskar is 54 and married to Meera Syal, with whom he has a son, and is from west London. After starting life above a launderette, he went on to work for IBM before giving it up for comedy and, latterly, making documentaries for the BBC.

Walker says their pairing worked from the beginning. “I was a fan of his work, and as soon as I sat down next to him at the first readthrough, which was when we met, I knew. They had written our names on little cardboard tags and they were next to each other, in this huge room with the executive producer, writer, director, all the other actors. And as soon as I sat down next to him, I thought, ‘This is going to be absolutely fine.’”

“I didn’t think it would work at all!” says Bhaskar, deadpan. “I’m still waiting for it to click in in any sort of shape, way or fashion.” Walker, who has known Bhaskar too long to be taken in, laughs. “OK,” he says. “Nicola is one of the most amazing people I’ve worked with.” In fact, Bhaskar admits, when they are not acting together he takes a proprietorial pride in her work. “I watched the series of Last Tango she did after Unforgotten and there’s a bit of me that goes, ‘That’s my friend, being fantastic.’”

Last Tango in Halifax, The Split… Walker has a standout drama CV. Bhaskar has made his name in broad comedy. “Comedy is seen on the outside as being easier,” says Bhaskar, “because there’s a very definitive reaction you need from comedy, and that’s laughter. From a drama, you don’t have people kind of waving audibly in order to know that you’ve got it right. It’s a physical, tangible thing.”

Many of Bhaskar’s shows, comedies such as Goodness Gracious Me and The Kumars at No 42, have emphasised his Asian background. “I was kind of surprised and impressed that Chris Lang had thought, ‘Yes, why can’t it be an Asian cop who is the partner?’” says Bhaskar. “And then they didn’t feel the need to load it up with references to justify there being an Asian bloke there. That ‘the corner shop didn’t work out so well’ thing. Khan is a real copper who applied for a job once and got it. And he happens to be part of this story.

“I feel just as strongly about the way that women have been portrayed in the past, and the older generation as well. In the end, it comes down to good storytelling. You can tick every kind of politically correct box and still end up with a box of crap.”

It’s a trope of even the most right-on modern crime series that a woman, often young and attractive, must be murdered, and it bugs Walker. “There have been jobs that I haven’t gone to the audition for because you think, ‘I don’t want to play someone who is violently murdered in episode two.’ Or ‘I don’t want to be in something that’s all about young women being murdered.’ There are some amazing dramas being made that use it as the dramatic hook, and say interesting things about us culturally and have really good stories, but not everything we make tells the story well.”
In the glass-fronted central London offices of law firm Noble & Hale, a woman sweeps past the banks of paralegal desks with bowls of branded boiled sweets and trainers hidden carefully in the footwells. It takes a few moments to register that this imposing, glamorous figure, tailored jacket, blonde highlights and all, is Nicola Walker, last seen playing a downtrodden cop in Unforgotten, a careworn farmer in Last Tango in Halifax and a lovelorn ghost in River.

New six-part BBC1 drama The Split, created by River’s writer, the Bafta-winning Abi Morgan, is a departure for Walker: the role of divorce lawyer Hannah Stern offers a welcome lead for someone who has been steadily moving up the credits since her career-making debut as Ruth Evershed in Spooks in 2003.

• When does The Split start on BBC1?
• Meet the cast of divorce drama The Split

“Dressing up was the thing I was really terrified of,” admits Walker, who was reduced to tears by Hannah’s vertiginous heels. “It’s not a world I understand, even in my own life. I’m used to being given no makeup, a pair of wellies and pushed on, but the clothes are a suit of armour for these lawyers. It does give you a sense of power, and you have to look reassuringly expensive for your clients.”

The Split is a rich soup of family trauma: Hannah, smarting over her mother’s refusal to hand over control of family firm Defoe’s, has jumped ship for the bigger, brasher Noble & Hale. Hannah is at a crossroads, and Walker conveys the lawyer’s cares with all her customary warmth and melancholy. The latter isn’t much in evidence with the actor in person, who is wry, cheerful company, both on set and when we meet some months later. She is, I note, wearing heels.

“Hannah has three kids, a lovely husband [played by Stephen Mangan] and a successful career,” says the 47-year-old actor. “It should be good, but it’s not. She spends all this time dealing with other people’s problem marriages, but her own personal life is becoming very complicated. There’s all kinds of chaos underneath the surface of this seemingly successful, driven, independent woman.”

Spending time with a real-life divorce lawyer was crucial to cracking the character. “It was helpful to see the combination of absolute professionalism and compassion, but a controlled form of compassion,” Walker explains. “You don’t see this job portrayed on television or film, and I realised that as actors we’re often doing impressions of other actors doing impressions of real people. This time, there was no research [on screen] you could do. You had to meet the real people.”

She herself is married, having met fellow actor Barnaby Kay in 1994, during a Royal Court production of The Libertine. Perhaps it was just as well that their wedding in 2013 came well before a series about divorce lawyers. “The Split is actually really hopeful,” she protests with a grin. “Although it’s left me reeling slightly, thinking about what we do to each other in the name of love, within the contract of marriage.”

So why sign that contract, after almost 20 years together? She cringes. “I don’t know if I should tell the truth – it doesn’t sound very romantic,” she laughs, before explaining it was to give their son, Harry, 11, a sense of security. “I find the whole ceremony of marriage a bit like going to work,” she says. “Putting on a lovely dress and make-up, learning lines, someone doing your hair… I can see that would be really appealing if you don’t do it for a living. It’s a public performance. Though we had a really lovely day because we didn’t do that. We had a tiny family thing.”

Family is as central to Walker’s life as it is to The Split. Born in east London and the daughter of a scrap-metal dealer and an interior designer, she was encouraged to pursue acting by her mother, however unlikely her chances of success then seemed. “There wasn’t really anything I wanted to do other than acting,” she says. “Which is ridiculous because there were no actors in my family and we didn’t know anything about acting. It was so beyond my understanding – I should have been making other plans. It all came from going to my local youth theatre in Essex. Then I got my agent when she came to see some fringe shows I was doing with Cambridge Footlights.”

Heading to London after graduating in English, Walker moved into a flat that sounds elike a sitcom waiting to be written. Her flatmates were writers Emma Kennedy (of The Kennedys and also 2012 Celebrity MasterChef champion); Sarah Phelps (writer of Ordeal by Innocence and other recent BBC Agatha Christie adaptations); and Sue Perkins, whose comic stooge Walker played in Footlights. They have remained close, and Walker has appeared in both Perkins’s 2013 comedy Heading Out and Phelps’s 2007 Oliver Twist.

• For the latest news and expert tips on getting the best deals this year, take a look at our Black Friday 2021 and Cyber Monday 2021

“I found two sisters,” she smiles. “With Sarah and Sue, it felt very much like the Defoe household [in The Split], except we didn’t have any money and got a lot more drunk. It’s easy to access, that delight in the company of brilliant, funny women.” This marks out The Split as particularly unusual for a primetime British drama. Alongside its female-led ensemble, 80 per cent of the heads of department, from composer to location manager, are women. Over recent years, Walker has worked extensively both with Jane Featherstone (executive producer of both The Split and Spooks) and Nicola Shindler (on Last Tango in Halifax and Scott & Bailey), so the experience is not as unusual for her as it might be for others.

“For a long time, it was, ‘Until women get into positions of power, nothing’s going to change’,” she says. “It was really unusual that the crews on Spooks were a real mix of men and women, and you’d struggle to see many women with parts that weren’t clichéd back in the late 90s. Now we’ve got female commissioners and executives like Jane and Nicola choosing the stories they want to tell, and actors like Sarah Lancashire putting in performances like in Happy Valley. I don’t feel we’ve ever seen that woman on TV before, and I hope people feel the same about Hannah.”