With 138 acting credits to his name, Stephen Graham has been directed by the likes of Martin Scorsese, Steve McQueen, and his Adolescence collaborator Philip Barantini. Yet none of them handle a film set like Jan Komasa, a 41-year-old Polish filmmaker whose new thriller, The Good Boy, has Graham playing against type as a moralising kidnapper of wayward teens.

“He’s fucking mental!” Graham tells me, in hysterics, pointing at Komasa. “But he’s absolutely brilliant.” The 52-year-old English actor demonstrates how he might prepare for a scene with a calming “Namu Myōhō Renge Kyō” mantra. “And then he’ll come in and be like…” Graham impersonates a machine gun. “He’s this mad, beautiful scientist throwing chemicals everywhere. And then you get into it. I’ve never experienced anything like it before in my life. Hopefully, I’ll get the opportunity to work with Jan again. But it’s absolutely barmy!”

I’m in a Covent Garden hotel with Graham, Komasa, and Kit Rakusen, a 15-year-old actor who plays Graham’s son in The Good Boy. “I can be really irritating and frustrating,” says Komasa with a smile. “I have to hear the music of the scene. I know what I want to shoot, but I forget it once we press play, because I see all the colours. I see the emotion. I’m overwhelmed. It’s probably my ADHD talking. And then I feel too much. That’s why I usually work with long takes, and ask the actors to do the same thing, if needed, from a certain point, with a different type of emotion. Some actors like it. Some actors hate it. Some actors want to control everything – it’s too contained, and they get pushed out of their comfort zone. It’s more fun when you shake everything up.”

The Good Boy – also known as Heel in America, where it was renamed due to a canine-related horror called Good Boy – is understandably a strange film requiring strange directing methods. In Yorkshire, 19-year-old Tommy (Anson Boon) heads out into clubs to snort coke, take pills, drink, tactically vomit, drink some more, and cheat on his girlfriend in the bathroom. In a substantially-worse-than-usual hangover, Tommy awakens chained up in the basement of an isolated house like a dog.

Tommy’s new owners and trainers are Chris (Graham) and Kathryn (Andrea Riseborough), a married couple determined to retrain their human pet for society by feeding him high art (classical music, the Ken Loach movie Kes) and forcing him to study TikTok videos of his past violent behaviour. Chris and Kathryn are, by this point, so calm and assured, it’s apparent that Tommy isn’t their first prisoner. They arguably have another one in their 12-year-old son, Jonathan (Rakusen), who’s eerily calm, even in the presence of Tommy screaming and yanking at the shackles around his neck.

Is Jonathan scared he’ll be next? “I don’t think so,” says Rakusen. “He is a good by. He’s very sheltered. He thinks this is all normal.”

“It’s every parent’s nightmare that, when they’re 9 or 10, they’ll go out on their own, and you can’t be there,” says Graham. “At some point, it has to happen. But for us, we’ve wrapped him up in cotton wool. He’s never had that experience.”

Early in development, The Good Boy was a Polish-language thriller that followed a football hooligan in Warsaw. Whereas Tommy’s clubbing antics are a five-minute montage in the finished, Yorkshire-set film, the Polish version would have had a completely different opening act. “In Poland, we have a higher tolerance for brutality in our cinema,” says Komasa. “Tommy was horrible for 40 minutes, doing the most mental stuff and attacking people on the streets. It was unbearable, but I loved it.”

It’s a social commentary on certain things that are happening. But then it’s dark and humorous in its own way

Komasa’s credits include Anniversary, Suicide Room, and the Oscar-nominated Corpus Cristi. While The Good Boy was toned down for its English-language rewrite, Komasa still directs the sadistic antics and twists with a playful cruelty that’s reminiscent of Jerzy Skolimowski, a producer on the project. “Polish and British culture are close when it comes to dark humour,” says Komasa. “All those films about football hooligans were a cult watch in Poland.”

“I was blown away by Corpus Christi,” says Graham. “I was looking forward to marrying that sensibility of British naturalism and socially relevant drama with that twist of European cinema. Jan’s done it in a really unique way. It’s a thriller. It’s a social commentary on certain things that are happening. But then it’s dark and humorous in its own way.”

The Good Boy can, as Graham attests, entertain popcorn audiences through its gritty yet absurd genre mash-ups: the tone, on paper, sounds like torture porn, yet it’s often a moving comedy that depicts Tommy gradually accepting, perhaps even adoring, his captors. Further insights into Chris and Kathryn’s marriage reveal deep grief, denial, and sexual frustration driving their motivations: everyone, not just Tommy, in this household is a prisoner to some extent.

In fact, Tommy and Chris share other chameleonic traits. Hellraiser Tommy is, secretly, middle-class. Conversely, working-class Chris wears a wig and attempts to hide his Scouse accent. Hearing my theory, Graham states that no one has made this observation yet from what he’s heard or read. “Chris is from – and I mean no disrespect – Birkenhead, which is not Liverpool,” says Graham. “He met his wife at university, joined the police force, and had aspirations to be part of her world – well-educated, a very affluent family. He felt out of place, but would do anything for her.”

Graham continues: “Tommy comes from a good home. But is it really a good home? His mum doesn’t seem bothered when he’s gone missing. His ma is more interested in yoga, and chatting to the fella. He’s obviously come from a dysfunctional family. That’s what we tried to marry with the two characters. They understand each other. But I just want to make him behave like a decent human being. My sense of what I want him to be a part of is kind of a good moral stance.” The actor laughs. “It’s just that my tactics are very, very screwed up.”

While The Good Boy is on the gnarlier side of cinema offerings, it’s also inadvertently a four-quadrant movie due to the various character studies: young and old can identify with someone. “The film was initially about Tommy, but then it became about this one family unit,” says Komasa. “Somewhere out there in Yorkshire, in the moors, in solitude together – they love it. As crazy as it sounds, it’s all about care in the end for them.”

Before the interview ends, Graham asks Rakusen to offer his favourite memory of working with Komasa. “There was one scene where you gave the analogy of a bomb being under the table, and to play into it, like stepping onto eggshells,” Rakusen tells the director. “It was always helpful.”

“I remember that day,” says Graham. “Most directors would go…” Graham whispers instructions into Rakusen’s ear. “And then walk away. But Jan comes in and goes” – Graham bellows at the top of his voice – “‘OK. THERE’S A BOMB UNDER THE TABLE. YOU CAN ALL HEAR THIS BANG. KID, THE BOMB’S ABOUT TO GO OFF. OK, NOW GO!!!!’” And then he runs away, and you go, ‘OK, shit. Let’s go. And that’s his beautiful, mad genius.”

“Well…” says Komasa, prompting everyone in the room to explode into laughter. “It is what it is.”

The Good Boy is out in UK cinemas now