The film centers on Efron’s Kevin Von Erich, the sole survivor of real-life nuclear family that once included 5 other sons: Jack Jr, David (Harris Dickinson), Kerry (Jeremy Allen White), Mike (Stanley Simons) and Chris.

Durkin cut the youngest brother, Chris, from the proceeding, since there’s only so much trauma an audience can handle. However, each brother was raised by their father Fritz Von Erich (Holt McCallany) in pressure cooker context, where they were held to impossibly high standards, and also subjected to Fritz’s shifting rankings of his favorite son.

Fritz taught his sons to withhold emotion no matter whom or what they lost, and Durkin saved the concluding emotional scene for the final day. Efron and his character finally got to experience the catharsis that was denied throughout the story.

“There were many moments in the film where his character wants to cry, to break, and I just kept saying, ‘No, not now, not here,’” Durkin says. “He was keeping it all in, and when we finally got to that final day, he was full of tears. We did 7 takes with the boys. He just kept going, and it was really amazing.”

Durkin shot the film’s wrestling scenes in visceral manner so that the audience can feel each moment of impact and the ensuing pain. As wrestling fan himself, the Canadian-American filmmaker wanted to make a point to anyone who demeans professional wrestlers.

Family was actually cursed?

I do not believe in curses, not in the mythical sense. I believe in psychology of curse, and when you’re in family where lot of bad things have happened, it’s very easy to believe you are going to get sucked into that pattern. Sometimes, that can almost become self-fulfilling, but that psychology certainly can take toll and act as much as the idea of a mythical course could act.

“Sports Dads” drive their kids to breaking points

Fritz is interesting story because he was going to play in the NFL, and then hurt his knee. Kevin was potentially on his way to the NFL, but hurt his knee. Kerry was on his way to the Olympics, but the boycott happened. There were alternate athletic paths for them, but ultimately, the family business was the thing to fall back on. Fritz fell into wrestling and then claimed he never wanted his boys to be wrestlers, but he obviously wanted them to be wrestlers. There’s contradiction there. But Fritz operated from place of love, as hard as he was and as damaging as some of his decisions were. He loved his boys and thought he was setting them up for the best life they could have. Obviously, he had some blind spots there, but I think his intention was for them.

The characters of Fritz McCallany and Rory Law are gaining from making decisions for their family, but they don’t mean to harm. That’s the difference, but they’re still very much patriarchs, making selfish decisions that cause harm, whether intentional or not.

Bringing out the best in actors?

First of all, it comes down to casting the right person for the role, or the person that I feel is right or I see something in them. It’s very instinctual, and once that happens, I believe in trust. I believe that if you cast someone, trust them to do their work and be there for them as much as they need you to be. For some people, that means talking every day for three months in the lead-up. Or, for some people, it means they read the script, we sit down for 15 minutes and then they say, “See you on set.”

Everybody is different, and each requires a different level of communication. I let them lead that, and I trust that, and I’m there to support it. Once we get there, it’s just about creating the best environment on the day for them to do their best work, and just being sensitive to what they’re walking in with that morning and what the scene requires. It’s just always being tuned in so they don’t need to tell me what they need. At that point, I know what they need, and I try to be there for them in that moment.

It was the very last day. I was crying because England had just been knocked out of the World Cup, so tears were flowing. But it was all leading up to that for Zac, because there were so many moments in the film where his character just wants to cry. His character just wants to break, and I just kept saying to him, “No, not now, not here.” And so he was keeping it all in, and when we finally got to that final day, he was just full of tears. It was incredible. We did seven takes of that shot with the boys. He just kept going, and it was really amazing. He had just saved it all up, and he was just really present. So there wasn’t much to it at that point. The kids were great, and everyone knew what it was.

Zac’s character runs the ropes in dramatic fashion

The timing is so precise between the steps and the ropes that it certainly takes on the rhythm of a train.

Creative license with bio films

Shooting the wrestling emphasizes the physical toll

As a wrestling fan, I feel so defensive about that argument. I feel outraged when people dismiss wrestling, because every form of entertainment that we consume is scripted, so what’s the difference? So I really considered it, but the other element is that, back then, wrestling was even more real. Kevin would actually connect with people, so there was a physicality and a brutality to that era of wrestling. I also just wanted to focus on the performative nature of wrestling. It doesn’t matter that it’s predetermined; it’s about how you perform and how you connect to an audience. The same goes for a musician playing a live performance or an actor in a play. It’s not just going through the motions or executing what’s planned. It’s about how you do it and the energy you do it with and how people respond to you, and wrestling is the same.

The Iron Claw opens in theaters on December 22.