Dylan Arnold is no stranger to intense roles, but stepping into Oppenheimer—a Christopher Nolan epic with a cast so stacked it reads like an Oscars guest list—was something else entirely. Arnold plays Frank Oppenheimer, the physicist younger brother of Cillian Murphy’s J. Robert Oppenheimer.
Landing the role? Pure Hollywood madness. “You get a self-tape for a Christopher Nolan movie and you just think, ‘Alright, let’s go,’” Arnold says. The audition involved a monologue about how stars die (casual) and a scene about military secrets. Months passed with radio silence, until Nolan himself requested an in-person audition—Arnold’s first in two and a half years. No pressure. “I figured, even if I don’t get it, meeting him is already a win,” he says.
Then he got the part. “That’s when the real fear sets in,” Arnold laughs. “It’s not just an idea anymore. You have to bring your A-game.” And with a cast like this—Murphy, Matt Damon, Robert Downey Jr., Emily Blunt—the pressure was immense. “You look around, and everyone’s the best at what they do. Even Matt Damon was like, ‘Isn’t this cool?’ And I’m thinking, ‘Yeah, dude, you’re Matt Damon!’”
Arnold dove into research, reading American Prometheus and a book on Frank Oppenheimer’s later work founding the Exploratorium in San Francisco. “Frank had this curiosity—he took apart a grand piano at 16 just to see how it worked, then stayed up all night putting it back together before his dad got home.” He also found something reassuring in how the Oppenheimer brothers weren’t just scientists—they were artists, musicians, and thinkers. “Frank could’ve been a professional flutist,” Arnold notes. “That’s not something you expect when you hear ‘Manhattan Project.’”
For Arnold, the movie isn’t just a historical epic—it’s a cautionary tale. “Look at AI today. People are so focused on what’s possible, they don’t stop to ask what happens next. It’s the same with nuclear weapons. The movie doesn’t tell you what to think, but it makes you think.”
Next up, Arnold stars in Lady in the Lake on Apple TV+, but Oppenheimer has already shifted his perspective. “Working with Nolan wasn’t even on my bucket list because I never thought it was possible,” he admits. “But now? I know I belong here.”
Watch the interview above and then check out the trailer below.
