John Hillcoat likes to refer to Nick Cave - a key collaborator on all of his movies including his latest, the stylish gangster epic Lawless - as his right hand man or 'the master".
It's easy to see why. Cave, the musician and author, is Hillcoat's creative soul mate. Lawless is the third movie Cave has written for Hillcoat and he's also compiled a brilliant, haunting soundtrack for the film featuring bluegrass artists performing contemporary rock classics, like Velvet Undergound's White Light/ White Heat.
And sharp-eyed fans of Cave might well spot him making a cameo appearance in Lawless too.
"Yes, I am actually in Lawless," Cave smiles. "There's a scene in Chicago at the very start with a dead gangster in a car - well, I'm the dead gangster."
So Cave is clearly in tune with Hillcoat and was involved with Lawless from the very start of the project. A gripping tale of outlaws who make moonshine in the backwoods of Virginia during Prohibition, the film is based on the book by Matt Bondurant, which recounts of the extraordinary exploits of his grandfather, Jack, and his two great uncles.
Hillcoat was hard at work filming The Road - his brilliant adaptation of Cormac McCarthy's post apocalyptic novel for which Cave created the soundtrack - when a colleague suggested he read Bondurant's book.
"I was actually doing the scene with Robert Duvall in The Road in the middle of nowhere and I got a call about this book that I had to read," says Hillcoat. "I did read it and it was fantastic.
"And I was looking for a gangster film to do, because I love genre films. But I couldn't find a new take on it and then I was told about this book, which was from the perspective of the people who created this kind of Al Capone-style gangster clan but in the backwoods.
"And so I gave it to my right arm - my friend and collaborator Nick Cave, the Master - and he responded to the material also."
He certainly did. "The book is amazing and I hope that the film renews some interest in the book because it's a stone classic of American literature," says Cave. "It's a great story and it's a true story.
"The book had an original idea in that it was really about the foot soldiers, the worker bees, that create the very beginning of the whole process of this wave of corruption that goes up and up into the cities and into the glamour and the gangsters wearing pin striped suits.
"And that's the territory that most filmmakers make films about - the glamorous side of the whole thing. And here was this really beautiful book about the workers and that seemed new and interesting."
Hillcoat's film is influenced by some of the classics of the American gangster genre - Brian De Palma's Scarface, Arthur Penn's Bonnie and Clyde and Sergio Leone's Once Upon A Time In America. Born in Australia, Hillcoat spent some time in North America when he was a teenager where he watched gangster movies whenever he could.
"What I'm fond of with those films in particular is that they had really strong filmmaking and characters and performances, which seems to be excluded from certain genres now," says Hillcoat.
"Gangster films nowadays are more about pure action, not characters. So it was a special treat to have such rich characters and a story that deals with the consequences of violence and treating violence - there is a lot of rich material in that."
The Bondurant Boys were outlaws who ran a restaurant and garage in Franklin County, Virginia - dubbed the Wettest County in the World because of the amount of illegal booze produced there during the Prohibition era - which was a front for their moonshine operation.
Tom Hardy plays the quiet, brooding Forrest who leads the clan and Jason Clarke is Howard, his second in command. Both men are capable of brutal violence when they need to protect their business and Forrest has earned a reputation as a formidable foe that, locals believe, is invincible.
Shia LaBeouf plays the youngest Bondurant, the ambitious, business savvy Jack, who is shielded from the violence but desperately wants to earn the respect of his older siblings and believes that their operation can expand and make them all very rich. Dean DeHaan is Cricket Pate, a sweet natured cousin of the Bondurants, who helps run the illegal stills.
The Bondurants profitably moonshine business is threatened by the arrival of a corrupt Chicago based special deputy Charley Rakes (Guy Pearce) who wants a cut of their profits. But the Bondurants refuse to back down and a brutal war breaks out.
Jessica Chastain is Maggie, a woman with a past, who takes a job at the Bonduant's restaurant and falls in love with Forrest. Mia Wasikowska is Bertha, the beautiful young daughter being raised in a religious family, who strikes up a secret relationship with Jack.
Lawless is, at times, graphically violent - but Cave believes that in the ever capable hands of Hillcoat it is never gratuitous. "I didn't have that much interest in when it was actually set, it was more the flavour of the book that took me," he says.
"I loved the kind of classical love stories that were involved in the story and the excessive violence and those two things coming together are what really kind of titillates me, kind of sentimentality and brute violence
"I'm not that interested in violence per se in films, a lot of it is very tedious and boring but there is something in the way that John deals with violence that I find really exciting right form the start, right from his early movies that no one even knows about.
"There was a relationship with violence that was really exciting. It's very brutal, very quick, it's all over very fast, but it leaves a huge mess behind, and that's what excites me about the way john deals with violence. It's not so much that gratuitous violence is of particular interest to me but more the way that john deals with it that is so exciting and refreshing."
For Hillcoat, working closely with Cave is an organic process. They discuss the idea behind the screenplay and then Cave writes the script before going back to the director with a draft, that's honed, and then in the case of Lawless, they workshoped the script in rehearsal with the cast.
"Film is such a delicate balancing act of so many elements and the fact is that Nick is the sole writer - because often scripts go through several different writers - and then it goes to the cast and it evolves in the rehearsals and the cast re-interpret things," says Hillcoat.
"And then it's reshaped in post (production) and Nick comes back in at the end with the music, so there's an extra kind of connective tissue there that for me is really special because most films aren't allowed to have that kind of connective tissue."
Cave adds: "It's not the process of writing a script in a vacuum and then sending it off to the director. And it's not about floating the script around trying to see if anyone is interested. It's not that process at all. So it's done very, very quickly."
Cave supervised the music for Lawless, gathering together a group of musicians - including Cave himself, Warren Ellis, Martyn Casey, George Vajestica and David Sard - collectively known as The Bootleggers.
They were joined, on various songs, by country legends Emmylou Harris and Ralph Stanley amongst others. Stanley, for example, performs a haunting rendition of White Light/ White Heat.
"As far as the music goes we didn't want to make a worthy Americana style soundtrack," explains Cave. "It's been done and it's been done very well in things like O Brother Where Art Thou and that kind of thing so we wanted to stay as far away from that as possible.
"And I think personally that this is actually a very modern film in a way, because Prohibition still exists today, and it still fails, with the so called war on drugs and all of that stuff.
"So there was a kind of gleeful idea of fusing modern day concerns, such as a Velvet Underground song about taking speed and amphetamine like White Light/ White Heat and doing it in a kind of bluegrass authentic American style that seemed to pull the present back to the past in a very pleasing way. That was the thinking behind that."
LAWLESS IS RELEASED IN THE UK AND IRELAND ON 7 SEPTEMBER