Brian Tyree Henry says the "simplicity" of 'Causeway' appealed to him.
The 40-year-old actor features alongside Jennifer Lawrence in the psychological drama and explained how the "stillness" of the project convinced him to join Lila Neugebauer's movie.
In an interview with The Hollywood Reporter, Brian said: "What drew me to the script was the simplicity of it, the stillness of it. There weren't scenes like, 'Here's the conflict, here's the climax'. It was actually just about being human and existing."
The film stars Brian and Jennifer as James and Lynsey. Both are survivors of trauma as she sustained a brain injury while serving in Afghanistan and he is a mechanic in New Orleans dealing with pain of his own and they slowly open up to each other as they explore a possible friendship.
The 'Bullet Train' star revealed that he wanted to explore the "grief" of his "tortured" alter ego.
Brian said: "The character of James was really appealing.
"There was something about this man – it was easy to look at him and think that he was somebody that was tortured, that he was somebody who was on the down-and-out.
"But I really wanted to understand how he got to where he was because I know he didn't start there. I know there was some sort of spirit in James, because of where he's from, what he does.
"But then this tragedy came about and changed him. I wanted to explore what his grief was, explore how he was navigating loss."
The actor explained how he and Jennifer figured out the true meaning of the movie in between takes on set.
He said: "The thing I didn't know was the connection that was going to pop out with Jennifer. We honestly discovered what the movie truly was in between takes.
"Really talking, calling each other out on our s***, really being around each other and realising that's the essence of who James and Lynsey are."