"I've co-written a film with my partner Anthony Byrne," she told PEOPLE at the Golden Globes on Sunday

Natalie Dormer Spills on the Upcoming Psychological Thriller She Stars in and Wrote

Natalie Dormer knows how to keep busy.

After wrapping her horror film The Forest (in theaters now), Dormer, 33, wasted no time getting back to work. The actress revealed that she’s about to begin production on a new film that she will star in and wrote.

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“I’ve co-written a film with my partner Anthony Byrne,” she told PEOPLE and at the Golden Globes red carpet Sunday. “We start production when I go back to London in a couple of months time.”

Dormer said she started writing the script for the film nearly five years ag, and will be playing a modern character in the “psychological thriller.”

“It’s set in contemporary London, so you’ll see me in jeans and a t-shirt,” she said – a very different look from her elaborate Game of Thrones or Hunger Games costumes.

“I’m moving away from the corsets and the semi-automatic riffles with the shaved head,” she joked. “I’m just trying to dress like a normal girl.”

Check out PEOPLE’s full Golden Globes 2016 coverage!

Dormer starts shooting the movie in March.