Fearless, frank and full-on:

three words that come to mind when thinking about Kate Dickie.

Consider her in Game Of Thrones as Lady Regent Lysa Arryn, breast-feeding her eight-year-old son while on the throne. Or in the recent Irvine Welsh adaptation Filth, as she and James McAvoy's corrupt copper strangle each other for sexual kicks.

In reality, the 42-year-old actress is as modest as these characters are extreme. "Every time I got a job, I'd phone my sister and go 'I'm going to be found out this time'," she says.

Yet after Andrea Arnold cast her in 2006's Red Road, as a CCTV operator confronted with a man from her past, quite the opposite occurred. Dickie won a Scottish Bafta and Best Actress at the British Independent Film Awards (beating Helen Mirren to the latter prize).

Since Red Road, she's been invited to party with the likes of Shane Meadows on Somers Town and the legendary Ridley Scott on his Alien prequel Prometheus, much to her shock. "I was like 'Are you sure they didn't mean to phone a different Kate?'" Her co-star in the latter, Michael Fassbender "was so kind and took me under his wing" - which probably makes her the envy of just about every woman on the planet.

Not that Dickie, who has a nine-year-old daughter called Molly, has gone all Hollywood on us. This year has seen her in a series of Scottish productions - including the aforementioned Filth and Glasgow-set rom-com Not Another Happy Ending, alongside Karen Gillan. She's also recently spent time on Mull shooting The Silent Storm, a forthcoming drama co-starring Damian Lewis and Andrea Riseborough.

"It does feel like there's a lot getting made and coming out in Scotland, and also a lot of really varied stuff, which is wonderful," she says. Most potently, there's Paul Wright's feature debut For Those In Peril, a stunningly rendered poetic fable - shot in Gourdon, Aberdeenshire - about Aaron (George MacKay), a lone survivor from a fishing boat accident that claims the lives of five others, including his own brother.

Dickie plays his mother Cathy, already traumatised by the loss of one son and left helpless as Aaron gradually becomes more and more insular and isolated in the small-town community. "George - it's just a beautiful, beautiful performance from him," she says. "He broke my heart." The same can be said for Dickie, notably when she delivers a pathos-drenched karaoke rendition of The First Time Ever I Saw Your Face in one scene.

Sadly, Dickie had, in a small way, experienced the film's central horror. In 2000, a scallop dredger named the Solway Harvester sank off the coast of the Isle of Man, killing all seven crew members who came from Dumfries and Galloway where Dickie grew up. "Quite a lot of boys that I knew from school were on it," she says quietly. "So I knew how a fishing tragedy can devastate a community and how devastating it is to lose young men in a community."

While Dickie had left the region when this had happened, she feels Wright has perfectly captured the way grief can envelop the soul. It's a topic they broached previously, when she played a corpse in his 2009 short Believe - about a widower unable to accept the loss of his wife. "From the moment I read that script, Paul said 'Would you consider playing the dead wife?' I said, 'Absolutely. I'd do it in a shot.'"

If it's hard to imagine most actors playing such a thankless (and lifeless) role, this is typical of her self-effacing style. From the outset, she "didn't have any plan", yet she's known she's wanted to act since she took drama classes at school. "From the age of 10, I realised you could do this for a job," she says. "Once I realised this was something that existed, it just felt right."

Joining an amateur dramatics group - the Newton Stewart Community Players - she feels lucky that she had support from her parents. "My dad was always 'You have to do what your dreams are, you have to follow your dreams.' He was very, very encouraging - to say, 'If that's what you want to do, you have to do it. Life's too short not to grab what you want.' I didn't have pressure, people saying 'Don't be silly' or 'That's not a proper job!."

Perhaps unsurprisingly, given its popularity, it's Game Of Thrones she now gets most recognised for. "I've only been seen in season one, so it is unusual to have people coming up to you." But will she, as her agent has claimed, be returning for next year's anticipated fourth season? "I can't comment on that at the moment," she blushes. "I'm so sorry." And just for a moment, she seems almost abashed to be so top secret.

For Those In Peril is released tomorrow