In the rip-roaring new action fantasy from Disney+, Renegade Nell, Derry Girls’ Louisa Harland stars as the titular character, who finds herself framed for murder in 18th century England, and subsequently becomes the country’s most feared highwaywoman. However, when a magical spirit called Billy Blind (Nick Mohammed) appears to her, Nell realises she has an even greater destiny in store, as – in classic Robin Hood fashion – she takes on her enemies amongst the English upper classes.

Writer Sally Wainwright skilfully blends action, comedy and drama throughout the series, and Harland acknowledges it was a delight to play.

“I don’t think I had a bad day on set,” says the Dublin actress. “I’d never really done anything similar before – I can’t even ride a bike! But that made it all the more exciting, and I just felt so lucky to get the opportunity to do something so different from myself, with all the challenges that go with it. Now, I have a newfound love for all these genres. Even to watch, I’m more interested in watching these fantasy adventure shows.”

Did it take long for the two actors to establish their comedic chemistry?

“Weirdly, we didn’t actually film anything together,” replies Mohammed. “But we rehearsed for one day and did voice tests. Also, we knew each other’s work, so I was never concerned that there wouldn’t be a dynamic. It’s all there in the writing. It’s quite nice to see it all put together now, because we’d done our stuff individually. That’s the magic of TV and film, really – it’s all an illusion, but it feels like a real relationship with a proper dynamic.”

When it comes to the influences on Renegade Nell, director Ben Taylor says there were different sources of inspiration.

“The truth is that in designing a show like this, you have a lot of references,” he says. “You hope that by having a lot of references, it will find its own shape and voice, and that it won’t be totally clear I’m just ripping stuff off! (laughs) In terms of tone, Pirates Of The Caribbean was always a North Star for us, because it had the ambition of action and VFX, but also had humour very close to its heart. So that made sense.

“Also, the word ‘swashbuckling’ goes in and out of vogue, and there’s no way of avoiding it – we were making a swashbuckling show for Disney. So Pirates was a big thing. Visually, we were really led by westerns, and the fact that no one really makes them in this country. The Coen brothers’ True Grit was a brilliant reference, because it was beautiful, and it was young and female-led. And it had a modernity to it, even though it was strictly period, so that was a key reference as well.”

For the actors, the special effects were another component they had to get to grips with. “That was new to me,” nods Louisa. “Obviously, I did Boys From County Hell, but this was a completely different game. I don’t think there was any green screen on Derry Girls!”

“I hadn’t done any wire work before,” adds Nick. “Oddly, there is a lot of green screen in Ted Lasso, which I was also in. A lot of the stadiums and the football players were done that way, although you can’t really tell.  You’re representing the real world, so it’s seamless.”

Class warfare is a notable theme throughout Renegade Nell, with the villain even having echoes of Rupert Murdoch.

“It’s brilliant and so well thought-out,” says Louisa. “It’s not preachy. Sally’s such an incredible writer and she tends to get it right. She wrote this 10 or 15 years ago, but it’s still commenting on today’s society. She’s amazing and I really think class is where the show is centred.”

Frank Dillane as Isambard, Joely Richardson as Lady Eularia. Cr. Rekha Garton/Disney+

“Even thought it feels like a departure because it’s swashbuckling and there’s a supernatural element,” says Nick, “thematically, it focuses on social injustice, and there’s a strong heroine at the heart. Also, class warfare and protecting one’s family – these are themes that are quite common in Sally’s work. She manages to add these elements – including the comment on journalism, like you were saying – even though this is a fantastical 18th century adventure series.

“It’s phenomenal really and it’s always played with such a deft hand, and with so many characters who feel real and well-rounded.”

For Taylor as director, given the action sequences and sundry effects, was Renegade Nell a complex show to put together?

“The action was something that drew me to it,” he reflects. “You can get lost in it. There’s a danger that you get so excited about the fights, you ignore everything else you’ve got to cover in the other 50 minutes. But it is complicated, so we would grade fight sequences in terms of how complex we wanted them to be. You were thinking in terms of how many days we needed to achieve it, and how many resources we needed to push towards it.

“So, there are some where Nell gets in a scrap and she’s just punching people and flipping them over. That, we got really good at – we did it very efficiently. But for example, the opening fight sequence was shot over three-and-a-half days, and it involved a lot of wire work and stunt-doubling. Then you had pyrotechnics, guns and huge slow motion cameras that could shoot at thousands of frames a second.

“So we threw everything at that one. We wanted the opening scene to grab you and not let you go. As a result, that scene became our main focus.”

Ramon Tikaram as Mr. Honeycombe, Ashna Rabheru as Polly. Cr. Chiabella James/Disney+

When it comes to the style of the series, Nick notes how it draws on mythology.

“A lot of the fantastical element, which Billy is obviously part of, was based on folklore of the time,” he says. “Sally wanted to write within that world. But with Renegade Nell, it almost feels like getting to rewrite history to a degree, in terms of having a highwaywoman. It’s a family show and that’s very difficult to do– it feels like it should be easier, but I think it’s a really tricky genre to get right.

“You don’t want to patronise adults and young adults, who might want to sit down and watch it with the kids, but equally you don’t want to be so scary that you alienate young viewers. So it has a great balance.”

Is there significantly more work involved in period pieces?

“It took two hours to get my ears on,” says Nick. “The amount of detail that goes into it – it’s testament to the costume department and the whole design team, really. But also just getting into costume – it took about 20 minutes to get into the Billy Blind stuff, because of the harness and making sure everything’s fitting right.”

“It was my own hair, which I got lucky with,” adds Louisa. “I wore a lot of dry-lip, which is basically clear nail varnish. They put it on your lips in the morning and leave it to dry. Then you crack it and it gives you a worn look. Nell is on horseback – she’s wrecked and she looks it!”

• Renegade Nell is available to stream now on Disney+.