Natalie Dormer has admitted that writing the movie “In Darkness” with her fiancé Anthony Byrne was no easy feat.

Before speaking at the World Humanitarian Day event at the United Nations Headquarters on Friday, Aug. 19, People caught up with the “Game of Thrones” alum and asked her what it was like to collaborate with Byrne on the script of the upcoming thriller.

“It's tough!” said the 34-year-old actress. “I don't know if you've ever been in a writing room but I wouldn't recommend it with your other half.”

Despite all the challenges that they encountered while writing the film, Dormer is still looking forward about the prospect of starring in a movie she also wrote for the first time.

“I'm very excited about it because I've never done anything that I've written before,” the “Hunger Games” actress said. “It was a very interesting process we were trying to write real interesting characters, both male and female.”

According to Sunday World, Dormer also loved the experience of working on the film from scratch.

“I've learnt so much about the mechanics of how a film is made,” she said. “To see and appreciate that you're a cog in a wheel of a much bigger thing happening in front of and behind the camera is a healthy thing for an actor. Now I'm just dying to get on set and tell the story. It's scary because we don't have a lot of time. But nothing worth doing isn't scary, right?”

“In Darkness,” which is Dormer’s writing debut, tells the story of a blind musician who heard a murder in the apartment upstairs from hers. The spine-chilling experience sends her down a dark path into London's gritty criminal underworld.

According to the IMDb, the film also stars Emily Ratajkowski, Ed Skrein and Stacy Martin.

Natalie Dormer, Anthony Byrne “Game of Thrones” alum Natalie Dormer admitted that co-writing the movie “In Darkness” with her fiancé Anthony Byrne was not as easy as she thought it would be. Pictured: Dormer and Byrne arrive at 6th Annual 'Oscar Wilde: Honoring the Irish in Film' Pre-Academy Awards party held at the Ebell Club of Los Angeles on Feb. 24, 2011 in Los Angeles, Calif. Photo: Getty Images/Alberto E. Rodriguez