What to expect from return of Liar with Joanne Froggatt of Downton Abbey fame

“Towards the end of the first season, I was going to the airport to fly to the States and literally all of the airport staff said, ‘Oh my goodness! We’ve been talking about this in the loo all week for the past three weeks’,” recalls Joanne Froggatt, who plays lead character Laura Nielson.

“From going through security to getting on the flight, I think 11 people came over super-excited and said they loved it.”

However, the next day, it became clear that something had gone wrong, and things spiralled out of control when Laura accused Andrew of rape.

Viewers were left asking the question: what had really happened that night?

A few episodes later, we discovered Laura was telling the truth, and Andrew is a monstrous sexual predator.

Then, with plenty of twists and turns along the way, the first series of the psychological thriller ended with Andrew dead.

“What we do in series two is go over the last three weeks between Andrew disappearing and turning up dead,” explains Yorkshire-born Froggatt, 39, famous for Downton Abbey.

“So, we go back over that time period to see who’s the liar now, about who killed him, and how we got there.”

Welshman Gruffudd, 46 - who is best known for ITV war drama Hornblower - suggests Liar is a very heavy, difficult show to watch, especially as the reality of Andrew’s actions and the impact of that on people’s lives really hits home.

Playing the despicable character has been challenging emotionally - even more so this series, which the writers have said will be the last.

“You don’t want to sound flippant, but it’s been an incredible opportunity to play something like this,” notes the star earnestly.

“I’ll forever be grateful for someone believing in me that I could present this kind of character. I wouldn’t say I’d be sad that it’s over because it’s emotionally draining on a daily basis.

“I hadn’t quite imagined how much impact it would have on me personally.

“There are moments where I’m playing the scenes and we cut, and I burst into tears, only because you have to invest so much to make it believable.”

The father-of-two continues candidly: “Also, you’re trying not to comment on it as a human being, but you’re very aware of what you’re doing, and have to represent, manipulate and pretend that everything’s fine. It makes you feel a bit sick.”

What state of mind is Laura in when we first see her in series two?

“We see her relatively together, in a happier moment with her and Ian, who is her fella she met in the first season,” details Froggatt.

“And then, very quickly, we move into the police have discovered Andrew Earlham’s body, and Laura is under suspicion, along with every other character in the show for very different reasons - and some of our new characters as well.

“Laura quickly switches back into her very determined, forthright self. She feels very angry still about the injustice of all that’s happened to her.”

Froggatt remembers how, after the first series was aired, at least six people came up to her to tell her their own personal stories which were similar to Laura’s situation.

They shared that they had been sexually assaulted, and then weren’t believed when they had spoken out about it.

“Someone told me their 19-year-old daughter had been assaulted and they’d been to the police and they knew who it was, but there’s no investigation being carried out.

“She very kindly said to me, ‘It was just so real - your anger was really exactly how we feel’, which was a very grounding thing for me to hear.

“It’s quite a responsibility to know that things like this do happen to people and those people are possibly going to be watching what you do. You want it to be as believable as possible for their sake.

“The worst thing for me would be someone watching what I do and think it was unbelievable, especially if they’ve been through that sort of experience themselves.”

Joanne, who was born and brought up in the village of Littlebeck in North Yorkshire where her parents, Ann and Keith, started a rare breed sheep farm on a smallholding near Whitby, has previously spoken of her love for playing “challenging women”, claiming she likes a character she can get her teeth into.

“I do like people who have layers to them, who are not always what they seem, who appear as one thing, and who are actually quite another. And Laura is certainly that,” she said in an interview with The Yorkshire Post in 2017.

“I always find it the most satisfying, as an actress, to play women who are flawed, but human.

“My own way of creating these women is to look into their psychologies. What drives them, what makes them who they are?”

Viewers can be sure to expect many tense and distressing scenes in the forthcoming Liar, with Laura still haunted by Andrew and what he did to her, and flashbacks detailing more about the past.

Discussing how they decompress after a day of filming, Gruffudd replies without hesitation: “Sleep!”, with which Froggatt agrees emphatically.

“I quite like a hot bath,” she adds. “God, we’re rock and roll - sleep and a hot bath!”

The star elaborates further: “I love watching drama, but at the end of the day, if I’ve been filming, or on stage, I come home and watch a documentary. That takes me out of my head as I completely empathise with what’s going on in real life. As we know, sometimes real life is stranger than fiction.

“It grounds me back into reality and makes me really appreciate where I am and what I’ve got.”

Chatty Froggatt says she’s “really proud” of the decision by Jack and Harry Williams - also responsible for BBC’s The Missing and Rellik - to only write two series of Liar.

“Their hope was that maybe there would be a second one, and that was as far as they wanted. They had this 12-episode arc that they could satisfyingly conclude in six, but would prefer to do 12. Then that’s really going to be the end of Andrew and Laura’s story. I think that’s really brave and honest with the viewers.

“There’s nothing worse than investing your time in something, and then investing your time again in the second season, and then you get to season three and think, ‘Oh, it’s all gone too far. I don’t believe it’.”

Liar returns to ITV on Monday, March 2.