Rose Leslie, the Scottish actress best known for playing Ygritte on HBO’s Game of Thrones, assumes an American accent as one half of a young New York couple in horror movie Honeymoon.

Rose Leslie On Nude ‘Birth’ Scene

Bea (Leslie) and Paul (Harry Treadaway) drive out to a cabin on a lake for their low-budget honeymoon following their wedding. It’s not long before the romance begins to wane. Instead of breakfast in bed and paddling around the lake, distrust starts to fester between the newlyweds, as an otherworldly force exerts itself on Bea, who leaves Paul in the dark about what has happened to her.

Paul eventually learns that something has gone freakishly wrong after tying Bea up on a bed and a graphic, bloody scene ensues. “Oh god! The most difficult scene,” Leslie admitted to uInterview. “I never knew how to really speak about it before, but someone in a previous interview called it ‘the birth.’”

Leading up to “the birth” there’s a slow, almost plodding lead up that shows the dissolution of Bea’s relationship with Paul. Leslie believes that the gradual build up is one of the thriller’s biggest strengths.

“I thought that, rather wonderfully, it was a nice build in the fact that it wasn’t in one extreme,” Leslie said. “I mean obviously the film is about seeing those cracks slowly begin to appear in what is seemingly a very strong relationship in the beginning.”

Leslie added, “What I found to be particularly interesting was to see that desolation between the two of them and the misplaced trust and the sort of crossed wires that they have and that there’s a proper lack of communication. So that enabled me to portray a slow transformation without just going from one end to the other.”

Honeymoon, directed by Leigh Janiak, who penned the screenplay with Phil Graziadie, hits theaters Sept. 12.