With a career that has now spanned two decades, and seen efforts ranging from micro-budget indies (“Following“) to superhero movies (“The Dark Knight” trilogy) to original blockbusters (“Inception“) to a documentary about cult animators (“Quay“), we’ll basically buy a ticket for whatever Christopher Nolan does next. The filmmaker always seems eager to explore new terrain and “Dunkirk” might just be his most ambitious effort yet.

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A big WWII movie, shot on 65mm and IMAX, and being released right in the heart of the summer, Nolan seems to be looking to show a whole new side to his directorial abilities. And he’s even taking a risk with the cast, using largely unknown actors Fionn Whitehead, Aneurin Barnard, Harry Styles, James D’Arcy, Jack Lowden, and Barry Keoghan in the lead roles, with Tom Hardy, Mark Rylance, Kenneth Branagh, and Cillian Murphy bringing their veteran presence in support to chronicle Operation Dynamo, the near-miraculous evacuation of the British Expeditionary Force (BEF) and other Allied troops from the French seaport of Dunkirk, which took place from May-June of 1940.

Nolan has always succeeded in conjuring big pieces of entertainment and spectacle, but he can he provide popcorn thrills while keeping this true story tale gritty and grounded? We’ll find out when “Dunkirk” opens on July 21, 2017.