A car, a phone, night time. These three elements, writer-director Steven Knight says, were the starting points for his new film, Locke, but they were the end points, too. Add actor Tom Hardy, and you have pretty much all the ingredients of a deceptively simple work about a life in free fall.
Hardy plays the title character, a man heading down an English motorway on a journey that will change everything. Gradually, we discover who he is, where he's heading, as every aspect of his world begins to change. It all takes place inside the car, in real time. Hardy, on screen throughout, is the only person we see. Everyone else is a voice on the other end of his mobile phone.
Knight got the idea during preparations for an earlier film, when he made camera tests that involved shooting inside moving vehicles. He was so taken with those images of a car going down a motorway in darkness, he says "that I wondered if that could become a theatre in which you could put a play".
"And I was also interested in the idea that with telephone technology now, everyone is available to people from every part of their lives at all times."
Knight met Hardy (The Dark Knight Rises, Lawless) to talk about a different project, mentioned the Locke idea to him, and got an immediate response. "I think he's the best we have," Knight says. 'And I wrote in the knowledge that he would do it, subject to him liking the script, which was a big luxury."
There's an audacious simplicity about the idea of Locke, and it was the same with the way it was shot.
"I wanted to offer people a vacation from the process of making a film. "Its always very arduous and difficult, and I wanted to do this in a very different way. So what I did was get a car on to the back of low-loader truck, put three cameras in the car, give Tom the script on autocue, and also in the rear-view mirror." Meanwhile, the other actors – playing characters such as Locke's wife, boss, employees, sons and a woman he once worked with – were in a hotel room with a phone line direct to the car. Knight, who was on the truck, would say "action", cue the actors in the hotel room, and filming would begin.
"We would film the whole film, from beginning to end, twice a night, as if it were a piece of theatre. It made it complicated, in a way, but it made it simple, too. We knew that when we set off, if something went wrong, we would just deal with it. We wouldn't stop, and we wouldn't do retakes."
Hardy took the opportunity to give different readings all the time. And Knight forced the issue a little for the actors on the other end of the phone line. For example, after three days of shooting, Knight wrote letters to the actors offering them different reasons for why they were doing what they were doing. "The script stayed exactly the same, but the motivations were completely different. Everyone was trying different things all the time."
Early on, it was decided that Locke would have a Welsh accent. "We wanted him to be English working-class, but a lot of English working-class accents are very harsh, and not internationally intelligible. But there's something about the Welsh accent. Tom listened to a lot of Richard Burton reading Under Milk Wood."
Simplicity had its complex ramifications. They ended up with 16 versions, and many permutations. "There are no continuity issues, because the background is moving lights, so I could cut between any take on any night, within the same phone conversation. It became a decision based solely on performance."
Knight is a prolific screenwriter, with several films awaiting release, some in development. He's created and written the period gangster TV series Peaky Blinders, and he's written Pawn Sacrifice, starring Tobey Maguire as chess champion Bobby Fischer. A film about haute cuisine, starring Bradley Cooper, is also in production. He has written a sequel to his Russian mafia drama, Eastern Promises. And there is a project he is writing and hoping to direct – about the last day in the life of a woman who has Alzheimer's, which he intends to be done "in a way that's positive".
Nor is the life of Locke over, it turns out. "Interestingly, in Italy and Germany, very reputable theatre directors have asked to put it on the stage. I've said yes, of course. And I'm hoping we'll do the same in London, with an actor, or maybe a series of actors, so that people could experience it that way."
Locke opens on August 28.