Lena Headey's pregnancy inspired 'The Trap'.

The 'Game of Thrones' actress makes her directorial debut with the movie, which is based on a short film she wrote and Lena revealed the idea first came to her 13 years ago when she was pregnant.

She told The Hollywood Reporter: "It came to me when I was pregnant 13 years ago. I was starting to panic. I was like, 'Am I capable of loving something? I don’t know what this is.' It makes you question love. Then when I had my baby, I wondered, 'Is love really unconditional? How far would you go? How much forgiveness is there? Would you really sacrifice everything for another person?'"

Lena, 50, cast her 'Game of Thrones' co-star Michelle Fairley in the character-driven psychological drama alongside James Nelson Joyce and admitted she wrote the movie with Michelle in mind.

She said: "We are great mates. I hunted her down, made her drink with me, and we’ve got a lovely friendship. I used to watch Michelle and she’s such a f****** beautiful actress, and I love her face. So I wrote this with her in mind. I wanted to be able to do all the things.

"I had offers along the way to do the film with big names. But no. This film is what I love about British cinema. It’s working-class actors. There are accents. It has all the little things we don’t look at. And I was like, f*** it — I’m just going to do the film that I know I want to make with the people I want to make it with."

Lena called the process of directing her first movie "f****** heaven" and added: "I love it because it is creating space for people to be vulnerable. I work with actors as an actor. I study what people do, and I know when you’re not giving what you can, or being lazy, or just not in the space that day. So I believe there is a way of talking to actors that will elicit something else. And I think every actor’s got a f****** rocking performance in them, they just need the words and a story that will serve them. But maybe you have to ask them."