Outlander TV series combines fantasy and drama in a scenic Scottish setting

With a somewhat fantastic premise – a woman transported through time from 1945 to 1743 – and the sweeping landscape of Scotland as its backdrop, it's easy to understand why Outlander is considered a fantasy drama.

But the show's producer Ron Moore is adamant that there is a line in the sand. "We said from the outset that the one fantastical element of the show was going to be the time travel aspect, and that is kind of it," he says. "Everything else we are at pains to make as grounded and real as possible."

Scenic storytelling: Catriona Balfe and Sam Heughan star in Outlander.

That would apply, Moore adds wryly, even if the show was set in outer space. "If everything around the characters feels real, the audience is much more likely to go with you on that journey, they're more likely to invest," he says. "If they don't believe the world, they distance themselves from the drama."

The series stars Caitriona Balfe as Claire Beauchamp Randall, a nurse whose journey through time re-aligns her romantic destiny in the direction of dashing Jamie Fraser played by Sam Heughan. (She left behind a husband, Frank Randall, who sort of returns in the form of his ancestor Black Jack Randall; Tobias Menzies plays both roles.

It is based on a series of books – now eight in total – by Diana Gabaldon. Moore, whose credits include Star Trek's spin-offs The Next Generation, Deep Space Nine and Voyager, and the critically exalted reboot of Battlestar Galactica, says he set out to make a series as faithful to the books as possible.

"I don't know that there's a general set of guidelines that we looked at, we're always sort of aware, we don't want to fundamentally change the characters, or fundamentally change the story," he says. "We know we're making changes along the way but let's not forget where we're trying to get to.

"It's a very subjective thing," he adds. "We debate it in the writers' room a lot, what to vary, what to keep. What are the critical moments for the character and for the story, and we just sort of make a judgement call as we go along. You might vary from it, you might take a detour [but] you're always trying to get back to the same place."

Though the series is produced for the US market it is filmed on location in Scotland. Moore concedes it could be filmed anywhere but the result would be less authentic. "On-screen, I think that the landscape itself is specific, and the light is actually very specific, cinematically," he says.

"And [Scotland] is not photographed that often, to audiences, so it has a certain sort of unique quality to it, visually," he adds. "There is a lot behind the scenes that gives this production a deeper, richer sense of being in a specific place, than if we were somewhere else trying to replicate it. You're not surrounded by people who come from that culture, and that tradition, who can actually speak to all the little tiny details."

The series has one notable connection to Moore's past work, the contribution of composer Bear McCreary, with whom he collaborated on Battlestar Galactica. (McCreary's other credits include The Walking Dead and Marvel's Agents of S.H.I.E.L.D.)

"Composers and scores deeply inform the audience, how they feel – worried, afraid, comedy, all of that. And then the texture of the landscape, and the tone of the piece, and how austere it is, or how rich and orchestral you're going," Moore says. "All of that stuff has always been extraordinarily important."

But McCreary was not on Moore's radar when he was developing Outlander, because he felt the composer would be too busy with other projects to take it on. An exchange of emails followed during which McCreary revealed he had written a student thesis on the Jacobites and had a keen interest in medieval Scottish music.

"He sent me an mp3 file in that email saying here's a piece of a traditional Scottish song that I did on the accordion just for fun, a year ago. And it was The Skye Boat Song, which I became obsessed with, and I wanted to use as the main title of the show. It just all went boom, he was so locked in to exactly what we wanted to be doing, and he loved the period, and it was just like, this is the perfect guy."

Earlier this year the US network Starz commissioned a second series of Outlander. Though the decision allows Moore to explore the world of Diana Gabaldon's characters more freely, he says he has no plans to deviate too much from the path laid out by the books.

"It wasn't so much, 'wow, now I can really take the shackles off, and we can go into these bigger ideas'; instead it was, now we can do the next one, and potentially the next one, and the next one, and so forth," he says. "We had a path that was sort of laid out for us, with the books."

"We know what we're doing next season, and it's going to be this book, and this is a completely different book. And this is a completely different set of challenges, and stories.It's just great to get the opportunity to do it."

Outlander, SOHO, Friday, 7.30pm