Director David Ayer has described the grueling production of his upcoming survival thriller, Heart of the Beast, starring Brad Pitt, revealing that Pitt frequently experienced hypothermia during filming. The movie centers on James Belmont, a retired soldier played by Pitt, who becomes stranded in the Alaskan wilderness with his dog, Odin.
Ayer, known for action films like The Beekeeper and Fury, told Polygon that the script's emotional depth was its primary appeal. However, he and Pitt underestimated the physical demands of the production. "Neither of us really understood how difficult it was going to be," Ayer stated.
Filming took place in remote mountain regions of New Zealand, where cast and crew endured constant exposure to cold, wet conditions, including freezing glacial water. Ayer noted that while the temperatures weren't always below freezing, the persistent rain and immersion in water led to Pitt often being hypothermic. "I think he was probably hypothermic the whole time. He's just sitting there on set freezing and shaking," Ayer recalled. Pitt's dedication to staying in character, even when enduring such discomfort, was a testament to the film's themes of endurance.
The film also features an ex-military dog named Uber playing Odin. Ayer, initially familiar with the Hollywood adage of not working with children or animals, developed a deep appreciation for Uber as a performer. Pitt actively participated in training Uber, which Ayer described as a significant aspect of his role, requiring him to maintain focus amidst the unpredictable nature of working with an animal actor. "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," Ayer said.
Despite its survival elements, Heart of the Beast incorporates considerable action, which Ayer found to be a different challenge compared to his previous work due to the wilderness setting. The production required navigating extremely remote and rugged terrain in New Zealand's Southern Alps, accessible primarily by helicopter. The filmmakers also secured permission from Maori elders to film in previously untouched areas.
Ayer views Heart of the Beast as an evolution in his career, calling it a deeply personal story about spiritual endurance and the bond between a man and his dog. He highlighted the storytelling challenge of a film with two main characters, one of whom does not speak, as a catalyst for his growth as a director.
Heart of the Beast is slated for release in theaters on September 25.