The Forest is Natalie Dormer's next big-screen outing, "It's a psychological, thinking-person horror movie," she says of the film, in which she plays a woman who travels to Japan to rescue her twin sister. "I really believe in the power of a story centred on the relationship between two siblings. We can all relate to receiving a phone call saying that a loved one is in trouble, in pain. I think that most of us will get on a plane and do something like this. And we all have regrets, things that we could change in our past if we could. That's what it is to be human."

Natalie Dormer stars in The Forest

For the 34-year-old English actress, it's important that she's playing a real character in whatever project she chooses. "I want to play real women," Dormer says. "When I read The Forest that's what I saw on the page in Sara. She seems very confident, but that comes, actually, from a deep, deep insecurity. So that was something that really spoke to me. And the interesting thing for me is to play Jess as well, who has dealt with this trauma that the girls have by going to the completely opposite end of the spectrum, by being the wild child."

She also loved the chance to shoot this film in a real forest. "I come from a hiking, outdoorsy family," she says. "I love being outside, but I don't enjoying being bitten to death by mosquitoes. There were a couple of times that we were shooting at 2am, freezing cold, and these mosquitoes started to attack. The only thing that kept me happy was the camera department and a bag of M&M's. That's the beautiful thing when you are the lead: you are in every single scene, every day, so you bond with your crew and become like a family."

This spring, Dormer will make In Darkness, a thriller she cowrote with her partner Anthony Byrne. Set in London, she calls this her passion project. "To me being a 'movie star' is almost irrelevant," she says. "I am just an actor, an English stage actor, that's what I was trained to do. If someone refers to me using that term it means that I have an audience that knows who I am and maybe wants to explore other stories with me."