Brad Pitt's New Survival Thriller Pushed Him to His Limits: "He Was Hypothermic the Whole Time"

David Ayer is best known for propulsive action thrillers (The Beekeeper, The Accountant) and heightened genre storytelling (Bright, Suicide Squad), but for his next movie, the director is trying something a little different. Heart of the Beast stars Brad Pitt as a retired soldier, James Belmont, who becomes stranded in the Alaskan wilderness with his ex-military dog Odin (played by dog actor Uber). Together, the two of them have to survive the harsh environment, while also grappling with their residual war-inflicted trauma.

Ayer tells Polygon he leaped at the opportunity to tell a more emotional, heartfelt story, and was thrilled when Pitt joined the project. Then came the realization of what they had both actually signed up for.

"Neither of us really understood how difficult it was going to be," Ayer says.

From helicoptering into the remote New Zealand mountain ranges where they filmed to getting soaked by rain and freezing-cold glacial water, shooting Heart of the Beast was a challenge on many levels. Working with a dog wasn't easy either, though Ayer says he came to appreciate Uber as just another actor on set.

For Polygon's fall preview, we spoke to Ayer over Zoom about the trials and triumphs of making Heart of the Beast, and how the film forced him to level-up as a director.

Polygon: What excited you most about making this movie?

David Ayer: It was a script. It was so impactful, so powerful. I was reading it and I'd start crying. I'd put it down. I like pacing. Okay, let's dive back in again. It was so emotional. There was something that resonated. Of course, I had no idea how hard it would actually be to make the film. But as a director, you can't pass up material like that. It just made perfect sense for Brad.

It was a journey we were both ready to go on emotionally, but we didn't know how physical it was gonna be. I think he was probably hypothermic the whole time. He's just sitting there on set freezing and shaking. I'm like, "Hey, you should go to the trailer and warm up." He's like, "Nah, I'll just have to get cold again." It's a film about endurance, but he demonstrated immense endurance in the filmmaking process.

Image: Paramount

How cold was it? Like below freezing?

No, not below freezing, but it's the rain and being in the water all the time — and it's glacier water. There was more water work than we expected. Working on mountains, just the remoteness of it and the ruggedness of it. There wasn't much comfort in the process.

This is also a dog movie. What was your experience directing a dog?

The classic saying in Hollywood is never work with children or animals, but then you look at the history of Hollywood and it's like, Lassie and Rin Tin Tin, they built studios. There's always been a love affair with dogs, with German Shepherds specifically.

I got schooled on working with dogs for sure. Brad got in early and really bonded with Uber and learned how to be a trainer. His role in a lot of ways was to manage the dog. He has a scene partner that could wander off, that could break the eye line, or starts chasing bees around. His ability to stay in character and stay focused no matter what Uber did was really incredible.

But at a certain point, I realized there's a performer in here. There's a soul. There's an actor. There's life in his eyes. It was such an amazing discovery.

Image: Paramount

Heart of the Beast is more of a survival movie, but the trailer has some action in it. How action-heavy is the movie?

There's a lot of action. It's a bit different than what I've done. You have the military piece, but the wilderness action was the biggest challenge. That was really new for me. You read the script — and maybe I should have read it a little more carefully — and you're like, "How the hell am I going to do that?" But we figured it out.

You shot in New Zealand. How did that affect the movie?

I've been up and down the South Island in New Zealand by helicopter. We went to very remote places. We'd land the helicopter at an angle on a boulder field and jump out and take our pictures. You'd see these beautiful mountains — they call it the Southern Alps — and then the helicopter comes around and there's even a more beautiful site. It's just like constantly unwrapping presents.

We had to get permission from the Maori elders who controlled some of those areas, basically sealed off from the world. And they were so gracious. They let us shoot in places that had never been shot in before. There were locations where we had to helicopter in for the day and drop equipment. Places with no roads or access. So it was rugged, but you see it on the screen. It's gorgeous.

Image: Paramount

You're mostly known as an action movie director. Does this feel like a big shift for your career?

It's an evolution for sure. It's a deeply personal story and it's deceptive in its simplicity: To guide a dog in the woods. How hard is that? But it's a love story. It's about spiritual endurance and not giving up on each other. Plus, you have one actor that talks and one actor that doesn't. So from a storytelling craft point of view, it just forced incredible growth on me.

Heart of the Beast releases in theaters on Sept. 25.