To be cast in an Irvine Welsh drama was a “pinch-me moment”, says Joanna Vanderham.

The actress plays DS Amanda Drummond in the Scottish novelist’s latest page-to-screen adaptation, Crime, a six-part psychological procedural thriller – coming to ITVX – that begets a battle for the soul.

“Being Scottish, he’s just such an icon!” quips the 32-year-old, who was born in Perth, Scotland, and grew up in Scone and Dundee.

“I was first introduced to his work through Trainspotting the film, and then I went back to the books. I was like, ‘Who is this? What is this? This is incredible!’” she remembers. “And when I was at drama school, they made us do the famous ‘Choose Life’ monologue from the film.

“So, to now get to reclaim it, and do it properly and to really be working on his work the way that he wanted it done feels so special.”

Based on Welsh’s 2008 novel of the same name, Crime – the sequel to his earlier novel Filth – follows team DI Ray Lennox (played by the Emmy nominated Dougray Scott) and the newly promoted DS Drummond, as they investigate a schoolgirl’s abduction.

But in true drama fashion, the twists and turns keep coming as Lennox, desperate to know what happened to this child, wrestles with inner demons driven by his troubled past and long-kept secrets.

“If you were to describe Lennox, I think you would call him some sort of very rough, fragile, avenging angel who is determined to give a voice to those people who don’t have a voice in society, and to protect the vulnerable,” offers Scott, 57, who has been working on producing the series for a decade.

“Stuff happened to him as a kid and so he went into becoming a copper because he felt that was the best way to avenge what happened to him as a child,” he explains.

“So what makes him a great copper also makes him a bad copper: he’s impetuous, he works off the cuff, he works on instinct. He’s left field – he’ll go down alleyways that no-one else will go down in order to try and find the solution or the answer.

“Sometimes it works and sometimes it doesn’t work. But he’s deeply passionate about what he does.”

On the other foot, “My character wants to do everything by the book, because she hasn’t spent much time with people, working on real crimes,” compares The Runaway star, Vanderham. “So together, they battle over the best way to solve a crime.

“Eventually they start to see the light in each other’s practices, but it does take a minute for them to find their footing together,” she muses, “Which was fun to play. It’s that back and forth of, what am I going to do versus what are you going to do?”

It was important that Drummond comes into her own, especially as “she doesn’t really feature that heavily in the novel”, reasons Vanderham, whose co-stars also include the brilliant John Simm and Ken Stott.

“She features in Filth, so I read that, but she’s mainly talked about from a man’s point of view, rather than from her own perspective.”

Representing her character, then, in a male-dominated space, was crucial.

“It’s a big responsibility, because it is incredibly topical right now, and I felt like I wanted to do that justice,” she says. “But what’s interesting about Lennox is that he isn’t necessarily the dinosaur that she thinks he is.

“They learn from each other quite quickly and she doesn’t feel that she always has to beat the feminist drum with him, which I found refreshing.”

As for the heavy, all-consuming storyline – one of which Vanderham admits some friends refused to watch – it was a case of reading up on similar harrowing crimes for both her and Scott.

“It was as cheery as you can imagine…” she states. “But the thing that stuck with me is that a sane person, such as myself, tries to find a rhyme and reason. We try and think, ‘Well, [child murderers] must be behaving like this because of XYZ’ and try to find a pattern. And actually, there very often isn’t one.

“That’s because they aren’t sane people, they aren’t thinking logically like a normal person would. And that was something I had to wrap my head around.”

“I am a bit of a geek when it comes to research,” adds A Town Called Malice star, Scott.

“For years I’ve watched documentaries on serial killers. But obviously, for this, I’ve visited that whole dark, dark world. And I have this guy who I’ve spoken to a lot, Ian, who is an ex-policeman; he’s an adviser on the show. So, I went through everything procedural with him.”

The light relief came in Scott and Vanderham’s off-camera relationship, the pair confirm, which Vanderham praises for laughs and much-needed “companionable silence”.

“We had long days where it was just the two of us in a car or in an office, and it could get exhausting if you felt like you always had to be on,” she notes. “And so there was a real peace that came with just having some quiet time.”

“It did take me quite a long time to leave [the part] behind,” she follows. “I wasn’t sleeping terribly well, but I feel like that plays into the character because she seems like she’s got it all figured out, but as the series goes on, we realise that she’s this complicated person who’s also hiding something.

“So I hope it worked. I hope I didn’t just look like a tired actress.”

She must have been doing something right as a second series has been commissioned and filmed, with Vanderham and Scott once again leading a stellar line-up of Scottish talent including Stott, who will reprise his role as Chief Superintendent Bob Toal.

“I was thrilled when we when we found out [about the second series] because my character’s personal life is hinted at in the first, but in the second, we really delve into what’s going on when she’s not at work,” teases Vanderham.

“It explains so much of why she is the way she is, and then it starts to explore the power dynamics, which is also really topical.”

As for a third run? “I would love a third season because I think that there’s potential for everything to get even more crazy!” she finishes, laughing.

“Irvine’s already written it; we just need to convince everyone else…”

Crime is available to stream on ITVX from Thursday.