While Anna Friel’s performance as tortured character Marcella left viewers enthralled, the actress tells Georgia Humphreys the second series promises to push boundaries even further

ANNA Friel is recalling how she almost turned down the opportunity to play the lead in ITV crime drama hit Marcella. The British actress, who was applauded for her portrayal of a troubled detective suffering from ongoing sporadic fugue states, was concerned it would be just another cop drama.

"I just thought, 'Oh god, how can I do this?'," explains Friel, 41, of the Nordic-style crime series. "There's so many amazing female detectives that I didn't know what I could offer differently, so I had to really work hard on that. When it was received as well as it was, I thought, 'Well, maybe I have done something that's different and I've got my own ownership and my own stamp on it'. That was very nice."

The show, which proved one of the channel's top-rated dramas in 2016, is now back for a second series. And judging by its premise, writer Hans Rosenfeldt (known for Scandinavian drama The Bridge) has managed to up the ante.

Opening with the discovery of a schoolboy's body, Marcella (Friel) and her team are on the frontline of the investigation - and it's a case she has a personal connection with.

Friel, who says she "keeps being offered these dark, tortured, characters", promises series two of the twisty, London-set thriller pushes boundaries even more.

"The serial killers this time are to do with children, so whenever you embark on something so sensitive, it's a tricky thing to deal with," notes the Rochdale-born star. "A second series can't just be as good as the first," she states. "It needs to be better and take it to the next level and I really believe with this new series that we have done that. I hope the viewers agree!"

So how does she decompress after a long day of filming Marcella? "You have to just mentally prepare and think, 'For four and a half months, I'm not going to be the happiest bunny'," confesses the mother-of-one, who found fame in the mid-1990s in soap opera Brookside. "Two hours of god-damn traffic helps," she says of her journey to set. "I get so frustrated by the effing traffic. It used to take me 45 minutes from Windsor and I've honestly started to sound like my mother or my nana, all I talk about is traffic. But I love my AGA, I love to go home and cook - I find chopping very therapeutic."

Of her character's anxiety and stress, which viewers see come out "in extreme anger and physical force", she says it's simply all based on huge fear.

"We're all in this world right now and that woman's voice is incredibly important and powerful because people are getting a right and a time to speak out," she elaborates. "And for me it was concentrating on being a single mother who is very, very, very lonely, and having her children taken away from her."

It's a part that people can relate to perhaps more than ever before. "I do think women are feeling very empowered at the moment," she says. "And having a woman who is dealing with a mental illness, whilst working, being a single mum and trying to keep everything afloat is very relatable at the moment."

Friel won best actress at the 2017 International Emmy Awards for her role as Marcella and has high hopes the chilling series – it's full of jumpy moments – will return for another run.

"I think it was always intended to write it in three parts, so it's not season one, season two, season three, it's part one, part two, and part three," she reveals. "It depends whether people respond to this - hopefully momentum's not been lost because it's been such a long time. But I think because it's been successful throughout the world, that's what's really odd now, I go to Germany and France and they're like, 'Marcella, we love it, we love it!', and I'm like, 'What do I sound like French?'."

Next up is a starring role in ITV's Butterfly, which she is also co-producing. The sensitive drama sees the actress play the mum of a little boy called Max who wants to transition to become Maxine.

"It's about transgender, so it's a topic that has been massively debated and discussed, and I would urge anybody to not voice an opinion without doing their proper research, because I didn't have any idea the trauma that some of these poor angels are going through - and their parents, what they're going through as well," says Friel. "It's a continual battle and a struggle and it's hugely controversial but we all have to have empathy, heart and compassion."

After all, Friel doesn't tend to shy away from controversial topics. "I like things with a powerful medium," she says, "and if that's the way we can get a message across and it tells a story, even if it is fictional or a drama, I tend to go for those things."

Marcella returns to ITV on Monday, February 19.