Anna Friel and Amanda Burton talk about the new series of Marcella

But that’s exactly what happens in the long-awaited series three of ITV thriller Marcella.

After the explosive end of the second series, which saw the eponymous character – played by Anna Friel – at rock bottom, writer Hans Rosenfeldt (known for Scandi-noir drama, The Bridge) wasn’t sure where to go next with the storyline.

The unflinching and unrelenting detective had discovered she was to blame for the death of her own daughter and essentially wanted to erase herself.

So, the eight new episodes see her with a new persona – as an undercover detective called Keira Devlin who has been given the mission of infiltrating a crime family in Belfast.

As the series progresses, the lines between Marcella and Keira blur; how much of the past has really been left behind?

“We watch her mental health deteriorate more, to a certain degree, because the more and more she tries to suppress it, the more and more her subconscious gets louder and Marcella is basically saying, ‘I’m still here’,” suggests Rochdale-born Friel, 44, whose first professional acting job came aged 13, in Channel 4’s GBH.

“She fights with herself, preferring her undercover life to her real-life which, I didn’t realise, can actually be a danger with undercover police cops.”

There isn’t a ‘whodunnit’ this series; “it’s more about her getting in the underbody of this family who’s not particularly good”, teases Friel.

That family in question is the Maguires. And with their eyes across all their operations is matriarch Katherine, played by Northern Irish star Amanda Burton.

“She’s proud of the success the family has had since her husband died,” Burton, 64, notes of her character.

“Whilst in the early 90s her husband may have run a wholly criminal enterprise with paramilitary links, Katherine was responsible for steering it towards a legitimate operation, leaning on the contacts she and her husband developed in the underworld to power the expansion whilst maintaining a legitimate veneer.”

So, what is the relationship between Katherine and Keira, aka Marcella?

“Keira is brought into the Maguire family by someone who works for them and Katherine is very suspicious of her when they first meet,” explains Burton, known for her roles in Silent Witness, Peak Practice, and Brookside (which Friel also memorably starred in).

“As time goes on, Keira seems to be around the family a lot more, but she doesn’t really accept her as anything other than an intruder at the beginning; she’s incredibly vigilant and protective of her family.”

Burton, who was born in Londonderry, says it had been about seventeen years since she last filmed in Belfast.

She found it “fascinating” to go back and to see the immense change in the city.

“This time we were filming in places where it just wouldn’t have been possible to film back then. It was quite extraordinary and evoked a lot of emotional memories for me being there.”

Asked how she found it shooting in Northern Ireland, Friel – whose profile soared after starring in American mystery-comedy drama series Pushing Daisies – gushes that it was “the best”.

“The best crew – so hardworking,” she elaborates. “And I was with all my family; it’s where I spent most of my childhood, Belfast and Donegal. So, family who had never been able to visit me on set before could do, on a regular basis.”

The captivating actress – who has a daughter, Gracie, with her former partner, Harry Potter star David Thewlis – continues: “Belfast is a great city. And has some of the best educational systems I’ve ever seen in the world.

“Gracie moved school, to the Strathearn, which is an all-girls school, and she loved it so much that when she came back to England, she wanted to change her school here because she wanted more of a sense of a community.”

The only downside of the location for series three was the weather; Friel admits they got “rained out a lot”.

“We’d been shooting inside in this mansion, where a lot of the scenes take place, and we were desperately trying to get outside on this one [day].

“It had been so sunny and beautiful and course, the one day we went out, it lashed it down. I think it’s on my Instagram somewhere because it wasn’t like a normal regular rain downpour, it was like something you see in the rainforest.”

Another challenging part of filming was when Friel got an eye infection.

“We couldn’t shoot for one day because of that – I had to go to the hospital,” she confides. “That was entertaining!

“It wasn’t fantastic. But we coped, we managed. I think they shot the side of my face or something. There are ways to get around everything.”

When it comes to answering what her favourite part of playing Keria was, as opposed to Marcella, Friel has no hesitation.

“Obviously being blonde! That just gave it a whole different feel and swagger to her costumes from series 1 and 2, which had to change, because Marcella dresses for the family, not for herself.

“I wouldn’t say Marcella is an incredibly sexualised person; she doesn’t sexualise herself or things. But Keira does.”

Would she up for doing a fourth series?

“I love Marcella; I’m very attached to her,” muses Friel, considering her answer carefully.

“I think it would take lots of discussions to say, ‘Right, what can we do with her now?’ “It’s better to have three really strong series than a fourth weaker one, but if someone came up with a really good idea as to where it could go…” She pauses. “I can see her in South America! I think you could take her anywhere.”

When we chat over Zoom, it’s the November lockdown, and the discussion turns to whether the arts can continue to thrive with the impact of the Covid-19 pandemic.

Friel is passionate about the topic, insisting that “the art needs to be supported.

“We need art – if any time has ever shown us that, it’s now. I’ve relied on music so much. I’ve watched more television than I think I have in years!

“And it’s a career to be proud of, if you work in the arts. It’s not a hobby, it’s someone’s bread and butter, and I find it quite difficult to hear about ‘retraining’.

“I think there’s going to be a need for artists more than ever. Imagine the day we can all go back to watching live music and concerts and – please god – be able to go back to the theatre.”

The first two episodes of Marcella series three will air on ITV on Tuesday, January 26, with the entire series will be dropped on the ITV Hub and BritBox as the second episodes concludes.