At CinemaCon, the writer-director introduced a "prologue" clip of the film, which hits theaters on July 21.

For filmmaker Christopher Nolan, “Dunkirk” is much more than a war film. At CinemaCon on Wednesday, the writer-director explained during a Warner Bros. presentation that the film is a survival story that he’s been wanting to tell for a very long time. The movie follows the Allied soldiers in World War II who were trapped on France’s Dunkirk beach in 1940 facing almost certain death, being surrounded by the German Army.

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“They were faced with the choice between surrender and annihilation,” Nolan said. “The fact that this story ends in neither is why I believe Dunkirk to be one of the greatest stories in human history…It’s the ultimate suspense story.”

Before showing footage from the unfinished movie that previously screened before select IMAX screenings during the holidays, Nolan said that the story of Dunkirk is one that British people grow up with. “It’s in our DNA practically,” he said.

In the roughly five-minute “prologue” clip, soldiers carry a wounded man to a medic ship while bombs land in the water nearby, and Tom Hardy shoots down a German plane, only to run out of gas and stall out in the middle of the sky.

Nolan was determined to tell the story in the most visceral way possible. “I wanted to put the audience on that beach and in those spitfire planes,” he said.

“Dunkirk” features both established actors like Hardy, Mark Rylance, Kenneth Branagh and Cillian Murphy, as well as what Nolan called some “relative newcomers” (like Fionn Whitehead) and “faces that I think you’re going to come to know and love over the years,” he said. “This combination of talent produced an ensemble the likes of which I’ve never had before.”

READ MORE: Christopher Nolan Teases Tricky ‘Dunkirk’ Storytelling: ‘The Film is Told From Three Points of View’

Echoing the comments made by many filmmakers at CinemaCon, Nolan mentioned the importance of seeing the film on the big screen, a statement that received a strong round of applause from the exhibitors in the audience. “This is a story that needs to carry you through this suspenseful situation and make you feel like you’re there,” he said. “The only way to do that is with theatrical exhibition.”

“Dunkirk” hits theaters on July 21.

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