When it comes to playing a certain kind of toughness, the resilience of the drover's wife, nobody can hold a candle to Frances McDormand. Three Billboards Outside Ebbing, Missouri is the proof. British director Martin McDonagh wrote the part of Mildred, a shop assistant in a small town determined to push the police to find her daughter's killer, specifically for McDormand. It took four years, so he didn't tell her about it - he barely knew her - just wrote the script and sent it off. If she hadn't wanted to take on the role, McDonagh says he wouldn't have known what to do. "There's no one else who could have played it," he says.
Mildred is determined. She doesn't smile much. Nine months before we meet her, her daughter was raped on her way home and left to die. When she decides to take on the local police, it is as if she has launched the Mother Wars. McDormand describes the film as a Greek tragedy, although it is also very funny. Her husband has left, so she sees no reason not to sell his tractor and spend the money on three roadside billboards. "Raped while dying," reads the first. "And Still No Arrests," says the second. And finally: "How Come, Chief Willoughby?"
The signs are on a little-used back road, but they work. The pot is duly stirred; the television cameras arrive; the locals rally behind the popular police chief, played by Woody Harrelson; one of his junior officers - a violent, wayward redneck, given monstrous force by Sam Rockwell - takes it upon himself to silence her. The ex-husband (John Hawkes), another violent man who lives with a 19-year-old who doesn't know the difference between polo and polio, is furious with her trouble-making. Mildred remains staunch. She has to do something and, as far as she can see, there is nothing else she can do.
McDormand, a regular with the Coen Brothers - she is married to Joel Coen - decided she should wear the same boiler-suit for the entire film. That is what Mildred is like: she is funny, but never parodic. "There aren't very many people who can do working class without judgment, without standing back and saying 'that's what they're like'," says McDonagh. "Both Frances and I come from that background. It's natural for us not to make someone like Mildred into a caricature." Sam Rockwell says he watches her and simply believes she is Mildred. "Frances is a very idiosyncratic person. She's the only person who could get on top of a billboard on fire and try to put it out. She seems just nutty enough, she has enough conviction, to do that."
McDonagh has followed the festival trail from Venice to Toronto to San Sebastian spruiking his film; London Film Festival has yet to roll around. Like most people at the Spanish festival, he looks beatifically relaxed; he also has several rounds of enthusiastic reviews, roaring audiences and talk of Oscars to help him through the jetlag. McDonagh is 47. Most of his work has been for the theatre. Three Billboards outside Ebbing, Missouri is his third film after In Bruges (2008) and Seven Psychopaths (2012). Those earlier films had the same kind of slicing dialogue and sure-footed jumps between drama and comedy, but the rich texture and gravitas of Three Billboards puts it in another league.
McDonagh had been nursing the image of those accusing billboards for a long time. "I saw something similar when I was on a bus going through America about 17 years ago," he says. "It just stuck in my mind and after 10 years I thought well, who would have put that there? And once I'd decided it was the mother - it must be the mother - it was almost like the story had to be written." The story and the characters led him into scenes he hadn't envisaged. He says he was surprised every day he was writing by what Mildred did and how the police would try to retaliate. He was also surprised by its final hopefulness. "That surprised me in the edit. Because of the humanity that Sam and Fran and Woody brought to their characters, a sense of hope just kept appearing as we cut."
Sam Rockwell's character, Dixon, has to cover a lot of ground to get to that point. Mildred's first greeting to him - "How's it going in the n----- torturing business?" - seemingly tells us all we need to know about him. "There was a worry about whether the hero character should use that word," says McDonagh. "But I was never worried about it because the scene is about exploding his stupid racism." Dixon is slow on the uptake, in thrall to his witchy mother and habitually vicious, but there is a streak in him that aspires to decency.
Rockwell guesses that he has played about 10 Southerners on screen and a lot of racists. "I think it's hilarious because I've played a lot of cowboys and rednecks and I'm a city kid." His first screen Southerner was the trailer-trash man with a mower in Lawn Dogs, directed by Australia's John Duigan; in another of his forthcoming films, The Best of Enemies, he plays a leader of the Ku Klux Klan. While researching that role, he consulted a former white supremacist.
"And he said something to me. He said it's not so much you hate black people or brown people, it's that you hate yourself. That is something we can all relate to." Rockwell developed a swaggering walk for Dixon he copied from the local police. "There's a kind of chest puffiness to it. This guy over-compensates a bit; he's got a classic Napoleonic complex. He's goofy, but he's dangerous. That's what I like about it. He's not just a momma's boy, he's a lot of things."
There are still plenty of Dixons out there, as recent real-life events in Missouri have made horribly evident. That worried McDonagh. "The script was written about eight years ago. I wouldn't want anyone to think I'd latched on to Missouri as the evil state and for this to be a comment on Missouri." It had to be one of the Confederate states, but it could have been any of them. "So it was almost like: do we change it? But I decided that would be equally bogus, so we'll see what happens when it comes out."
What concerned him more was that the film shouldn't feel like an outsider's view of wacky, wrong-headed America. "I don't make any judgment call about America or Americans, because down that road lies caricature and we don't want to go there. I try to be truthful to the characters." Even if those characters are, as he readily agrees, heightened, swollen versions of themselves. "I guess that comes from the theatre, but movie characters are allowed to be a bit bigger than life I think. It's not a kitchen sink drama; I'm not crazy about those. Mildred is larger than life but, hopefully, completely truthful. She could be a tough cookie, Fran, but the character is a tough cookie so it's just like a perfect melding of cookies."
So we're back to Mildred. McDormand isn't in San Sebastian, because one of her convictions in real life is that she isn't going to spend time doing press. "She plays by her rules," says Rockwell. "She does her thing and it works for her, you know?" McDormand hasn't had surgery and doesn't do Botox. "And the no-makeup thing, that's part of her agenda. It's beautiful to see an older, strong woman wave that flag; I think it's really rare and beautiful. I find her a heroic person, a heartfelt person and I think you do have to have those qualities in order to play somebody like that."
Another thing that McDormand almost certainly isn't doing: the schmoozing and lobbying required of most actors as the awards season gets under way. McDormand has already won an Oscar for her performance as Marge Gunderson in Fargo, so it isn't impossible to break through. And she certainly deserves this year's statuette. The film should win Best Picture. She's that good. It's that good. "I wasn't sure if audiences could recover from what they see on the billboards and still laugh," says McDonagh. "I wasn't sure if there would be walkouts. I knew in my heart what I was trying to do, which was to honour the daughter, the mother and the story but you're never sure if something that bleak would be just a no-go area. It wasn't until we started showing it to people that I realised it was OK." Right now, McDonagh has every reason to smile.
Three Billboards Outside Ebbing, Missouri will screen from January 1.