For the last two series of darkly comic crime drama Tin Star, the Worths have been on the run in Canada.

Now though, the family has regrouped back to the UK; reinvigorated, they're ready to take on their historic foes and face a dark truth they ran from 20 years earlier.

The final instalment of the Sky original series sees the trio - Jack Worth (Tim Roth), Anna Worth (Abigail Lawrie) and Angela Worth (Genevieve O'Reilly) - working as a team, and operating in Liverpool, which executive producer Alison Jackson teases "allows for the madness, that we all love about the Worth family, in spades".

"It was a journey into the backstory, for the family," London-born Roth, 59, notes of filming Tin Star: Liverpool, written by Rowan Joffe.

"We'd had glimpses, through their trials and tribulations, of what they were, and we'd sowed the seeds of that once we'd figured out we were heading back to Liverpool - back home in a sense. But it was quite the wild journey for everybody."

23-year-old Lawrie, who hails from Aberdeen, recalls there were a lot of revelations in season two about Anna's dad, and who her parents really were - and says the idea of going to Liverpool was "really, really exciting".

But it was "a big risk to take a show that's really established itself in Canada, and just move it to a completely different setting", muses the young star, who also appeared in the BBC's adaptation of J. K. Rowling's The Casual Vacancy.

And Jackson - who has also worked on dramas Law & Order UK and Moving Wallpaper - admits there were definitely challenges that arose from moving to Liverpool for the new episodes.

"We were so blessed in Canada, with incredible landscapes that are so easy to make look cinematic and ambitious; it's different in Liverpool.

"However, the challenge was a really great one, that we were all excited by because Liverpool in itself is such a majestic city, and it's such a city of contrast and optimism."

"The people we met while we were filming, they were so proud of where they were from; they were so friendly, they were welcoming," gushes Irish actress O'Reilly - known for her work in the Star Wars franchise as Mon Mothma - when discussing filming in Liverpool.

"There was a massive crowd scene of Everton supporters and that day is really seared into my memory because there were people from Sheffield, from Chester, from Manchester," elaborates the Dublin-born star, 43.

"They'd come in that morning on different buses and we were all gathered together, in the cold obviously, chatting and having cups of tea together and it was really special, and I'm so aware right now that that couldn't happen (because of Covid-19). I feel like we were so lucky to have it."

Since it first aired in 2017, Tin Star has cemented itself as a gritty watch; it doesn't shy away from depicting violence on screen.

And Jackson confirms that this final instalment - which sees the Worths (who have secrets which could blow Liverpool apart) face up to a group of dangerous criminals who are still operating in the city - "gets very dark".

"I think, for me, one of the things I love about Tin Star is that the dark is always set off by a form of wit - never gags, it always comes from character.

"And I think sometimes you find yourself laughing when you feel you shouldn't be, but you're just having a great time and you can't help it."

One of series three's lighter moments comes in episode one; there are brilliant karaoke scenes, which Hollywood royalty Roth reveals were born out of their time on set in Canada.

"Weather was stopping play and we couldn't film, so I'd end up sitting in a car with these guys (Genevieve and Abigail) and they would have a sing-off. Like, for real," quips the star, who's famous for films such as Pulp Fiction, Reservoir Dogs and Planet of the Apes, plus TV roles such as the 2017 revival of Twin Peaks.

"It was show tunes central. It was insane. So, we had to have that kind of thing happen (in season 3) and the idea of finding her (Anna) on stage in a karaoke club, it only seemed natural to me."

"I was absolutely bricking it, I was so nervous, and we had a list of songs to choose from, and of course we chose Spice Girls," confides Lawrie. "Once I did it once, it was like I was actually on a night out, it was great. And all the SA's (supporting actors) that day ... We had drag queens in, it was so much fun!"

Both O'Reilly and Roth jump in here to affirm how "amazing" the drag queens were.

"I think it was definitely one of my favourite days ever filming," enthuses Lawrie.

"You were so good!" says O'Reilly. "You sang it again and again, and all those drag queens, they were in like eight-inch heels; I had never seen heels as big as they were wearing, and they were dancing. We had so much fun."

Jackson reveals that she would "never say never" to doing more series of Tin Star, and that "it could come back" one day.

However, the team certainly went into filming season three knowing that it would be the conclusion of the big overarching story.

So, as we say goodbye to the Worths - for now at least - what have the cast members loved the most about their roles?

"I think Anna's quite a badass, especially in season 3; she knows exactly what she wants, she's very decisive and she goes after it, so I love that about her," says Lawrie.

"And she knows how to use a gun! There's a lot of cool things that I got to do in season 3."

"I love how complicated Angela is," follows O'Reilly.

"I knew she was troubled, I knew she'd had a fractured past, I knew she was escaping it, but season three really allowed me to discover her."

Tin Star: Liverpool airs on Sky Atlantic and Now TV on Thursday, December 10 and all episodes are available as a box set.