Cillian Murphy On the 'Huge Responsibility' of Christopher Nolan's Oppenheimer

There are lots of reasons to have Oppenheimer on your list of this summer's must-see movies, and one of the most compelling is the relationship between the film's writer/director and its star. The epic historical drama from Christopher Nolan marks his sixth collaboration with actor Cillian Murphy, who's been working with the director ever since Batman Begins. Unlike those Batman films, though, this time around Murphy's got the title role. 

“I have always said publicly and privately, to Chris, that if I’m available and you want me to be in a movie, I’m there," Murphy told the Associated Press this week in an interview about the film. "I don’t really care about the size of the part. But deep down, secretly, I was desperate to play a lead for him.”

RELATED: Christopher Nolan calls Oppenheimer 'both dream and nightmare'

Now Murphy has his chance as he steps into the shoes of J. Robert Oppenheimer, the legendary and, to many, infamous physicist whose work as head of the Los Alamos Laboratory led to the creation of the first atomic bombs. As we've seen in trailers, the film grapples not just with the race to make the bomb work for potential use in World War II, but with Oppenheimer's own intellectual and emotional understanding of the risks involved in creating such a weapon. That meant a very meaty role for Murphy, and since he was playing a real person, a great responsibility to history.

“You realize this is a huge responsibility. He was complicated and contradictory and so iconic,” Murphy said. “But you know you’re with one of the great directors of all time. I felt confident going into it with Chris. He’s had a profound impact on my life, creatively and professionally. He’s offered me very interesting roles ... and I’ve found all of them really challenging. And I just love being on his sets.”

Beyond that, of course, Murphy isn't saying too much. Oppenheimer is, like all Nolan films, still under the cover of the director's secrecy until its July release date unveils it to the world. Though the movie is based on real history, and you can go read up on what happened for yourself in the lead-up to seeing it on the big screen, Oppenheimer's star is still waiting to talk particulars until after the film hits theaters.

“There’s an awful lot to talk about when we can talk freely,” Murphy said.

Oppenheimer arrives in theaters July 21.

Jonesing for another thriller based on true events? A Friend of the Family is now streaming on Peacock.