Christopher Nolan And Cillian MurphyThe working relationship of spans nearly 20 years and counts since the filmmaker directed the favorite “Peaky Blinders” in six films: Three films Batman, “Inception”, “Dunkirk” and “Oppenheimer.” Notably, however, the upcoming A-Bomb drama marks the first time Murphy has headlined an image of Nolan in the lead role. Murphy stars as theoretical physicist and “father of the atomic bomb” J. Robert Oppenheimer. In a recent interview with the Associated Pressthe actor admitted he “was desperate” to direct a Nolan movie.

“I’ve always said publicly and privately to Chris that if I’m available and you want me to be in a movie, I’m here. I don’t really care about the size of the room,” Murphy said. “But deep down, secretly, I was desperate to play a lead role for him.”

Murphy landed the lead role in “Oppenheimer” via a cold call offer from Nolan.

“He’s so low-key and self-deprecating and, in his very English way, he just said, ‘Listen, I wrote this script, it’s about Oppenheimer. I wish you were my Oppenheimer,” Murphy said. “It was a great day… We have this understanding, this confidence, this shorthand and this long-standing respect. It was the right time to take on greater responsibility. And it turns out it was huge.

“Oppenheimer” is based on the 2005 book “American Prometheus” by Kai Bird and Martin J. Sherwin and follows the physicist as he struggles with the creation of the atomic bomb during World War II.

“You realize that’s a huge responsibility. He was convoluted and contradictory and so iconic,” Murphy said of the character. I felt confident going with Chris. He had a profound impact on my life, both creatively and professionally. He offered me some very interesting roles and I found them all really challenging. And I love being on its trays.

“The question will be how Chris presents it,” Murphy added of the film. “I think people will be very surprised and impressed with what he does. Everything I say will just sound a little lame compared to seeing this in an IMAX theater.

Joining Murphy in “Oppenheimer” is an all-star cast that includes Emily Blunt as Katherine “Kitty” Oppenheimer, Matt Damon as the director of the Manhattan Project, General Leslie Groves Jr. and Robert Downey Jr. as of Lewis Strauss, a founding commissioner of the United States. Central commission of nuclear energy. Florence Pugh, Benny Safdie, Michael Angarano, Josh Hartnett, Rami Malek, Dane DeHaan, Dylan Arnold, David Krumholtz, Alden Ehrenreich and Matthew Modine also star.

Murphy revealed last year that in preparing to play Oppenheimer, he ignored all the mechanics of what makes an atomic bomb and instead focused on the man himself.

“[I prepped by doing] a lot of reading,” Murphy said recently. The Guardian. “I am interested in the man and in what [inventing the atomic bomb] made to the individual. The mechanics aren’t really for me – I don’t have the intellectual capacity to figure them out, but these contradictory characters are fascinating.

“Oppenheimer” opens in theaters July 21 from Universal Pictures.