When taking on the responsibility of bringing the harrowing journey of the British boxer Billy Moore, who had all but disappeared into the recesses of a Thai prison after being arrested on drug charges, to the screen in “A Prayer Before Dawn,” Jean-Stéphane Sauvaire knew that hit audiences in the gut, he’d have to go through the ears.

“When you are in a prison in a cell at night for example, you can hear every detail because you know you are in a state of danger — something is going to happen — so you’ll hear everything much more accurate,” says Sauvaire. “The punches and hearing the gloves on the flesh and the sweat — all this stuff that [you have in] boxing scenes, you always have the same kind of sound design for punches, but it doesn’t really sound like the real sound of a punch when you go into the ring.”

Sauvaire was in search of something so intensely real that it might be perceived as unreal, which could be a good way of describing his films in general. Parlaying an early career as an assistant director for the likes of Gaspar Noe into blurring reality and fiction at the helm himself, he first applied dramatic techniques to make audiences feel as if they were alongside a 13-year-old boy living in one of Colombia’s most dangerous neighborhoods in the 2004 documentary “Carlitos Medellin” before reworking the equation to tell the story of child soldiers in Liberia in “Johnny Mad Dog,” with much of the teenage cast having actually fought in the Second Liberian Civil War. A decade would pass before the director could make his follow-up, but the wait was well worth it for “A Prayer Before Dawn” in which audiences are thrown into Chiang Mai Penetentiary with Billy, who was trying to make a name for himself on the Muay Thai fight circuit before lapsing back into the heroin addiction he was trying to run from when he left Liverpool. Crowded into a cell where not all the bodies have a pulse, he quickly realizes that he must use his wits not to join the dead, discovering that his brawling skills might come in handy for exhibitions the prison staff stages with other prisons and gradually makes connections with the right gang members, as well as a trans woman who works the jail’s supply store, inside to survive.

While discipline emerges as a greater strength for Billy than his fists, Sauvaire intentionally overwhelms audiences to treat them to an experience they’ve never had before, letting the cacophony of sirens blaring and shackles clanking during an evening lockdown give the tactile sensation of feeling concrete against your bare feet and filling every room with barely clothed, heavily tattooed men who often swarm around the random fights that break out or the daily dispersal of drinking water with the might of ocean waves. However, as fearless as Sauvaire was in arranging this reality to fit his cinematic needs, he might be outdone by Joe Cole, the “Peaky Blinders” star who plays Billy not with a swagger, but resilience that comes from the education of being constantly humbled by a situation he couldn’t have possibly imagined for himself, an awe surely informed by the fact that the director didn’t spare him of experiencing this world as Billy actually did. With the film making its way to American theaters and DirecTV this week after premiering at Cannes last summer, Sauvaire and Cole spoke about how the visceral experience of “A Prayer Before Dawn” grew out of a strict adherence to what really happened to Moore, using real former prisoners and current prison guards to ensure authenticity and even finding a role for Moore to play that added resonance to this blistering drama.

Joe Cole in "A Prayer Before Dawn"How’d you get interested in Billy’s life?

Jean-Stéphane Sauvaire: Rita Dagher, the producer in fact brought me the story, and [said] it’s a story set in Thailand, it’s boxing, it’s a prison movie. It’s about addiction. It’s based on a true story and I said, “Wow, those sound like the elements I love, so I’d be happy to read it” and then they give me Billy Moore’s memoir of his experience in prison in Thailand and his childhood in Liverpool and I read it and I said, “Wow, I need to meet this guy.” I met him in Liverpool and he’s a really vulnerable, sensitive guy — a really nice guy with this violent background — and I said I really love this guy and we started from there, from his book, talking together and rewriting the script, trying to start the process of the film.

Joe Cole: I share an agent with Jean-Stéphane, and I believe he saw a film I did called “Offender” about a young guy who seeks revenge on some career criminals and breaks into a young offender’s institute in England and goes after them, and felt I could bring the right vulnerability and physicality to the role. He knew Billy quite well [by the time I was cast] and it was important for Jean for me to meet Billy because he understood how Billy was such a fascinating character and not [necessarily] who I might think he is. He has far more layers. He’s not just a fighter. He’s a beautiful, charismatic, funny human being, almost like a little boy in a man’s body. Obviously, he suffers from addiction and he has great vulnerability and insecurities, but he’s just a beautiful human.

Joe, did you have any idea what you were getting into when you signed on?

Joe Cole: Yeah, I did because I’d seen “Johnny Mad Dog” and [Jean-Stéphane] goes to the places and he lives and breathes those worlds. Everything’s very authentic, [so I believed him when] he told me, “Joe, we’re going to be going there and we’re going to be doing things for real. Every punch and kick has to connect and you’re going to feel like you are in a real fight.” A lot of boxing movies, the camera moves around the ring a lot of the time and goes with the audience and you don’t necessarily feel the fight in the same way. In our movie, it was important to actually hit and punch each other and to use the soundscape to really get that feeling of being in there with Billy in the ring.

Jean-Stéphane Sauvaire: Joe was the perfect guy from the UK. He had some experience with boxing, but not that much, so my idea was to immerse himself right away in this world of boxing first and then prison, almost as Billy experienced it for the first time. [Billy] went to Thailand where he was boxing and got arrested and went to prison, so [Joe] came for the first time for a month to do training two months before shooting the film in different boxing camps in Thailand — I wanted for him to box with different people, trying to be really immersed in this Muay Thai world. He had a session in the morning and then he got some rest and he had sessions in the afternoon, training everyday, and it was a way also for him to get to know the boxers who he was going to play [opposite] in the film, not just discovering people on set.

Joe Cole in "A Prayer Before Dawn"What was it like to find the prison in Thailand?

Jean-Stéphane Sauvaire: We found the prison pretty early in the process. I wanted to have a real prison and at first, I tried [to find] an active prison in Thailand, but they didn’t allow me. It was even difficult to visit some prisons. A line producer in Thailand found this location and I said, “Wow, that’s perfect” because the prison was empty [because] recently — they transferred all the prisoners to a modern prison — so it was like a set and there were all these different sectors. But we didn’t get the money for the film [immediately] and a year-and-a-half later [when we were ready to shoot,] the prison was damaged, but we recreated it with the production design department. We [actually] shot the last fight in an active prison in the Philippines.

When you find the prison, could you then actually cast within the region?

Jean-Stéphane Sauvaire: I did the casting mostly in Bangkok, looking for former prisoners, so some of them did their sentence in that prison — it’s 40 kilometers [away from Bangkok], but not all of them because there’s a lot of prisons. Sometimes even if you have one sentence, you can go in four or five different prisons in the country, but [when] I was staying in Bangkok for a few months to do the casting, [I had] the help of the [man who plays the] cell block king in the film, [whose] face is covered with tattoos. He really helped me because he spent time in prison and I [told him], “I want to do this film with nonprofessionals, with people who have the prison experience,” and every Sunday I was going to his house and he introduced me to 10 or 15 guys. I was taking pictures of them and I would interview them, which gave me a lot of information also for the script to be more realistic. Then I could feel which ones could eventually act in the film and then we did a kind of workshop with them — similar] art therapy as I did with the former child soldiers in Liberia [for “Johnny Mad Dog”] — for them to be able to act in the film and build this kind of trust together because there was always this worry [for] the production in Thailand [that] a guy would come for one day and then not come back for the shooting because they are not professional actors — maybe they are going to get involved in other stuff and they’re not going to come back.

It’s a risk, but within these months, we built a trust together and I think they really want to tell their story. It’s important. It’s not just for the money. It was also because they want to share something [about their experience] so I’m sure they’re going to be on set on time. And that’s what happened. Every day, they would travel 40-50 kilometers to come on set at six in the morning on time, and all together, to play 50 to 60 prisoners in the movie. So it’s amazing when you can share this with people — it’s more than a movie. It becomes a life experience, a human experience. Even the guards were the actual prison guards, and [when] they come into the cell, they wake up [the actors playing the prisoners] and they say, “You have to go in the yard” and then they’re trying to do a body search and when they find the drugs on Billy, for example, that was one shot, almost ten minutes, so when you start from the guards coming and waking up the prisoners up until the end, you don’t have time to stop.

Joe Cole in "A Prayer Before Dawn"Does language pose a barrier or does everybody gradually get on the same page?

Jean-Stéphane Sauvaire: For me, it was tough at the beginning because they don’t speak English and I tried to learn Thai, but it’s quite difficult because it’s really phonetic, so I always had an assistant — a student there with me translating. Then you forget that you have somebody between you doing the translation because you create this trust and I said maybe it’s more interesting to create our own language in the film. For example at the beginning of the film, all the Thai prisoners had lines in perfect English in the script and I said, “How am I going to do this?” because they don’t really speak English, so it’s going to be difficult to act if it’s not your own language. I did a test with Joe Cole when he came to Thailand for the first time. I said, okay, I want to try something — [we’ll] do an exercise with the gang members. You’re going to try and tell a story to each other, knowing that you don’t speak Thai and they don’t speak English, I want to see how you can communicate and find your own language. I realized after five minutes, they were able to communicate and I said, “That’s going to be the language of the film.”

Joe Cole: I started to learn Thai a little bit, but nobody on the film set except for me and my makeup artist spoke English, and what we found was the less Thai I spoke and the less English they spoke, the more fascinating the interactions were because we had to rely on body language and expression to get across what we were trying to convey. That’s ultimately a big part of what this movie’s about. It’s about this underlying communication through the body.

Jean-Stéphane Sauvaire: When you come here from the UK, surrounded sometimes by 20, 30 people — gang members — covered in tattoos, looking at you, speaking only Thai, I think you feel something. That was important for me to recreate this feeling and mood that Billy felt when he first entered into the prison. Joe Cole is very brave and we had a low budget, so we had to shoot a lot every day — every day of shooting, he had a fighting scene, and [was] being immersed in this world — so he was fantastic in the film because he’s living almost the situation as it was on set. We [also] shot also long, extended [takes], trying to recreate the reality in shooting as it was. As a director, I like to see the whole scene, not just part of it, from the beginning until the end to see if it’s realistic to my eye, and then to shoot [it].

Joe Cole: Jean shoots without cuts, so [you’ll do these] 10-minute takes [where] you forget you’re in a film. He has very little crew and very little equipment. He told the David Ungaro, [the cinematographer] that he wanted 360 degree movement of camera at any point, so when we did these scenes — that were loosely structured, but there was a lot of room for improvisation — it meant that the camera could go anywhere and I could sort of do what I wanted within the realms of authenticity and do as much as Billy Moore as possible. You do get lost in it.

Jean-Stéphane Sauvaire: I have a handheld camera or with a stabilizer, but always giving the freedom to the actors most of all to do what they have to do. We have a tight crew and we are more in the background helping between the takes. During the takes, I love to have a minimum of people and extend shots, sometimes 10 minutes [and] you can’t have people around, just the people in the scene trying to forget the technical part of it.

Joe Cole in "A Prayer Before Dawn"In the scenes that are absolute chaos — for instance when the entire prison population is fighting for water — do you even know what you’re getting before you see the dailies?

Jean-Stéphane Sauvaire: [laughs] [David, the cinematographer] was like, “Let’s go. Let’s start” and I asked for the people to fight for the water and then [David] was immersed into it and with no fear. That was amazing because you don’t do that many takes [for a scene like that], but at least you have the feeling of what’s going on and people are screaming and trying to fight, so the DP had to fight to get his place [like everybody in the scene]. Even when he was in the ring when we did the fight scenes, sometimes he had to push the boxers to get to get the best shot possible, so the camera was was almost an actor — one of the prisoners. I really wanted this camera to be immersive, physical and visceral, trying to feel more than just describe, being inside the ring, but also inside the prison, being amongst the prisoners and never outside and just watching at the distance. But it was fun. We had some fun.

Joe Cole: Every day was a new experience and a new challenge. I really did feel like I was in prison at points and this real alienation because [all the others] knew each other and none of them really spoke English. They just spoke Thai, so that just added to the whole experience.

Are the long, fluid takes a particular challenge for the fight scenes, where so many punches and kicks need to be choreographed just right or someone gets hit for real?

Jean-Stéphane Sauvaire: There’s three [main] fights, and the first one was really chaotic, so [we didn’t practice it as much], but we really rehearsed the fight in the middle, and could only do three takes because it was really tough for the boxers and for the [crew] to do more than ten minutes three times. Then the last fight we rehearsed a lot with a different boxer who dropped out at the last moment because he had to do a fight in China, so I had to find another guy and we didn’t rehearse as much as I would expect, but every scene they knew more or less what they had to do.

Joe Cole: We tried to have a rough choreography for those fights, but obviously we were against the clock and we didn’t have the luxury of, say, “The Fast and the Furious” to prep a fight scene. We’d have a day or an afternoon, so ultimately things are going to go wrong and you’re just going to have to go with the flow of the fight and trust your dance partner. It didn’t always go according to plan, but I’ve got quite a lot of experience with fighting on camera. The more you do, the more you learn about controlling your body and being able to take a movie punch, so it was ultimately just a mixture of choreography and good instincts from myself and the other boxers.

Joe Cole in "A Prayer Before Dawn"The real Billy Moore makes an appearance — how did that scene come about? [SPOILERS AHEAD]

Jean-Stéphane Sauvaire: Billy wanted to have like a cameo in the film and I didn’t want any [random] foreigner in this prison, so I didn’t know which cameo I’m going to give him. But then came the idea of this last scene and I said, “Okay, if we do the last scene with Billy’s father, it would be great if it’s Billy,” because for me, it means much more than just a father coming at the end. It’s Billy facing himself [when he’s] older and it’s also Joe Cole facing the guy he just portrayed against the reality. I was interested in all this, so I talked to Billy and said, “Okay, I maybe have a cameo for you — [you’re] going to play your father.” And he said, “Wow, it’s going to be emotional and maybe I’m too young for that.” And I said, “Too young? No, it’s going to be okay.” And he said, “Yeah, but let me think about it.” [Ultimately] he said, “Okay, I want to do it,” and he was supposed to come on set [in Thailand], but now he’s blacklisted [there], so he came to the Philippines during the last days of shooting. We shot this on almost the last day, and it was an intense moment because Billy was really into it. You can feel the vulnerability of this guy in this one shot and I’m so proud that is now in the film, trying to reconnecting the film with the reality of the scene.

Joe Cole: It was a beautiful moment. There’s so much to that scene. It’s so much Billy coming to face his former self and coming to terms with who he is and almost finally forgiving himself and letting himself be free. Billy once told me that for a year or two while he was in Thailand, he was so insecure and hated himself so much that he couldn’t even look in the mirror. And I felt that moment was the moment where he looked at his former self and found some acceptance. It also shows the relationship that Billy had with his father and Billy’s father only told him that he loved him on his deathbed, moments before he died of cancer, and that’s why I thought it was so interesting to have Billy there. It was a moment of forgiveness.

“A Prayer Before Dawn” opens on August 10th in Los Angeles at the Arclight Hollywood and New York at the Village East Cinemas. It is also now available on DirecTV, iTunes, Amazon, Google Play, Xbox and Vudu.