Michael Fassbender was not immediately thought of for Connor.
"I saw Michael for the first time in a clip from Wedding Belles, an Irvin Welsh film. I hadn't seen Hunger or even knew about it at that point, though I became aware of it later. I though he was very charismatic in Wedding Belles and that was an important quality for Connor. I made a decision without meeting him on the strength of that clip really because he felt right and trust my instinct in that way. I don't like to question myself it feels right so just went for it".

Fassbender boarded the film without having read the script as Arnold didn't allow any of the actors to read it beforehand. They were given scenes only a few days before filming.

"Not having a script is kind of worrying and most of the time you wouldn't commit to something under those circumstances, but I'd seen Red Road and I really respected Andrea and wanted to work with her. I find her storytelling very interesting because it's in the grey area. She deals with human beings who have flaws and have good qualities and negative qualities and are basically just trying to figure their way through life".

"It was a very different way of working," comments Fassbender. "I usually like to digest the script and let it rot and then play with it when it comes to the day of filming so in this instance I tried to be as loose and relaxed as possible. That was the main note I gave myself. Andrea if very quick and off the cuff and works with whatever happens that day to organically feed her story and created a very comfortable space for the actors to work in."

Fassbender enjoyed working with Katie. "Katie is a very expressive person and very easy to play with as she's not really acting. In Andrea's hand you can get a very powerful performance in that way as very raw, it comes from the gut, it hasn't been over through, it's very intuitive." Katie, in turn, found Fassbender easy to work with. "He gave me advise about certain things and was really helpful," she says. "It felt but weird acting some scenes with him, but because I knew what he was like off camera it made it much easier."

"It was great working with Kierston," says Fassbender. "She's very no nonsense and when I first saw her I thought she looked like Brigitte Bardot. She's got this very interesting quality to her, she's very got this sultry, sexy rawness to her and she's very free and easy to work with. I watched IT'S A FREE WORLD while we were working and saw how talented she is, she's also fun."