TV: Drama thrills with a side of Nessie in new series The Loch

PEOPLE visit Loch Ness to detect a glimpse of a slippery, mystical monster, supposedly submerged in the deep Scottish lake, but in new six-part murder mystery, The Loch, a new, earthbound monster is on the prowl. When a man's body is discovered at the bottom of a mountain, and then a lone human heart materialises on the shore of Loch Ness, village cop Annie - played by Laura Fraser (Breaking Bad, The Missing, A Knight's Tale) - and DCI Lauren Quigley - Siobhan Finneran (Happy Valley, Benidorm, Downton Abbey) - are brought in to track down the killer.

Although Finneran actually did very little filming at Loch Ness - "I spent a lot of my summer in that police station" - Glasgow-born Fraser, 40, was very excited at the prospect of filming the series in her home country.

"It's strange being from Scotland and then filming in the countryside," she says. "I've not done my family lineage, but you feel sort of connected to it in some sort of ancient way - even if it's completely wrong. I looked up the geography of Loch Ness and found that a lot of Scotland is on this rupture, this fault line, from an eruption thousands of years ago."

She compares this geological schism to the fissures that appear between characters in the series: "This serial killer breaks the community apart, there are all these ruptures happening between the community, and at the same time they're all living on an active fault line.

"And then, just looking at that murky water ... it's a paper-thin veneer of civilisation that we're all pretending is okay, but beneath the surface it's actually horrific chaos threatening the land."

When it comes to believing in the supernatural though, and in the Loch Ness monster, Fraser jokes: "I saw Nessie, she's actually surprisingly small - and nice!"

Oldham-born Finneran, 51, is more circumspect. "That's always difficult, isn't it?" she muses. "If you've seen something, or had an experience, then of course you're much more likely to go 'Yes, I do believe'. I think I'm best to say I'm open to all of that kind of world, but I'm not sure really."

"Lauren Quigley is a tough cop who is actually pissed off that she's got to go to this backwater village to solve this crime, and thinks she'll go and it'll all be done within a couple of days," says Finneran of her character.

Meanwhile, it's Annie's first murder case. "She's teetering on the edge of bitterness because she's never really fulfilled her career desires, and she's made decisions for the wrong reasons. She's got a lot of built-up resentment at her husband and herself for doing that," explains Fraser. "The serial killer has given her an opportunity to fulfil her potential and become a better policewoman, and she really looks up to Quigley."

The pair eventually become allies, particularly as Quigley doesn't swoop in and sort the case out in 24 hours. "You're good at first, and then a bit shit!" says Fraser wryly.

"Really shit! I bring all those people with me and I still can't sort it out," says Finneran, with a laugh. "We end up with a whole selection of clues and not one of us can work out where to go with them, because they don't seem to fit together at all!"

Starring as two strong female leads in a major ITV drama is something neither woman takes for granted, but they're not blind to the fact that roles like these are still scant for women.

However, Fraser is quick to add that "it seems to be, at the moment, just cop shows" driving the change, and that's largely due to the impact of pioneering Scandinavia crime dramas proving so popular. Finneran agrees. "I was trying to think of another job, or another genre of drama that's doing that, and it's just a lot of cop shows." "I can actually solve crimes now I've done so many," says Fraser, deadpan.

"You get to over 40 as an actress and suddenly you are playing the policewoman, and also a woman has to be that age to have got to where she's got to within the police force, because it takes so much longer," explains Finneran. "They're normally in their 40s or 50s before they get to any ranking of any importance."

If they're not being booked to play cops though, they're being cast as mums, often mums in horror films.

"Well, I'm now doing 'grandma'!" says Finneran indignantly. "What happens is, the men my age are still playing the lead roles, but their wives are about 30, whereas if they do that with a woman, that's what the drama becomes about - it's about the fact a 50-year-old woman has a 30-year-old boyfriend, when that happens - believe you me - every day around the world!"

"I definitely think it's better now. I was really worried when I was about 25, looking ahead, when I couldn't see a lot in TV for women, but actually I've had much more interesting roles now than I had in my 20s," says Fraser, noting how playing drugs businesswoman Lydia Rodarte-Quayle in Breaking Bad, opposite Bryan Cranston's Walter White, "really changed things a lot for me", and says that without that opportunity she'd "probably be in the 40-50 doldrums" that a lot of actresses experience.

"It's definitely getting better," agrees Finneran, "but it's still really slow. The fact the dramas that have been a success over the past few years, because they've been led by female roles, makes everyone go 'This is great, it's all now working' - it's not actually, we're still miles, years behind, and we've got to push forward with it, but it is definitely moving in the right direction."

• The Loch airs on ITV from Sunday June 11