Cillian Murphy, Robert Downey Jr, Christopher Nolan attend Oppenheimer premiere

Cillian Murphy, Robert Downey Jr, Emily Blunt, Matt Damon and Christopher Nolan, on Tuesday, attended the grand premiere of their film Oppenheimer at the Cinema Le Grand Rex in Paris.

The three-hour historical epic was about to begin, Nolan warned the audience that it’s an intense experience, it’s a serious subject, but it’s something we pulled our hearts into. The movie delves into the creation of the atomic bomb during World War II.

Downey Jr., who arrived on the red carpet looking as sleek and fashionable as Tony Stark, said Oppenheimer stands out from his past films.

I’ve done a lot of movies where it kind of becomes about aliens and bad guys and action and flying around. But this is a blockbuster about our history as human beings. And it’s just amazing how he pulled it off,” said Downey Jr. who owes his huge popularity in France to his turn in Iron Man and The Avengers.

Murphy, who plays J. Robert Oppenheimer, an American theoretical physicist, kept a low profile on the red carpet.

Blunt, who looked beautiful in a silk gown, said it was an “extraordinary set, fully immersive, which is what Chris adores to do, so you feel kidnapped by the experience as an actor.”

The biopic, set during World War II, follows Oppenheimer, known as the Father of the Atomic Bomb, during a period in history when he understood that testing the atomic bomb would ignite the atmosphere and destroy the world, yet he pushed the button anyway.