Josh Brolin has arguably been the most industrious American actor of the past year. In Robert Rodriguez’ Grindhouse homage Planet Terror, he was full of ticks and outlandish gimmicks as Dr William Block. In American Gangster Brolin acted Russell Crowe and Denzel Washington off the screen as the corrupt New York cop Detective Trupo. This fortnight we have the pleasure of seeing Brolin twice, playing Chief Buchwald in Paul Haggis’ In The Valley of Elah and also in the Coens’ No Country For Old Men. It’s in this Cormac McCarthy adaptation that the 39-year-old delivers his best performance to date.

Brolin recounts how he first heard about the part when in Austin, Texas. ‘I was turned on to the book by the playwright Sam Shepherd. We were out one night and he told me that I should read this book. I knew Cormac and his writing, but I hadn’t read that particular book. I liked how the narrative popped back and forth between all these characters. Shepherd told me that the Coen Brothers were going to do an adaptation.’

Brolin started courting the Coen Brothers for a part but they did not always feel the need to uphold their end of the conversation. ‘They’re a quiet bunch. I had Ethan go out for dinner with me and he brought a book, which he started reading during dinner. I tried to remind him that I was at the dinner table too, and he said, “I’m sorry”. They think I’m insane. The worst fear for any director is having actors say to them that you have a great script you think should be their next film. So anytime there was a silence I’d say, “I think I have this really good idea for a film, it’s loosely based on Fargo.” Since then, every time we email, I say I’ve almost finished the script.’

Playing midnight cowboy Llewelyn Moss was a role that Brolin immediately connected with: ‘I’ve stolen many things in my life, but that was a past life. I didn’t use that experience for the character. I have a lot of childhood friends like Llewelyn Moss, so it wasn’t difficult to imagine him. My focus was on creating a subtle character: it’s almost like the dialogue is in the body language and how he presents himself in this very physical way is his own country vernacular. As a country boy myself who grew up around these people I don’t know one person in the community I grew up in who wouldn’t have taken that $4 million.’

It’s at this point that Brolin raises one eyebrow with a smirk on his face. He’s an enigmatic character who’s sometimes difficult to read. In addition to acting he writes plays and has his own theatre company, but like so many things associated with the man, we’re only now discovering the true nature of his talents.

No Country For Old Men, general release from Fri 18 Jan. In The Valley of Elah, general release from Fri 25 Jan.