'Dunkirk' Trailer: Kenneth Branagh, Tom Hardy, and Harry Styles In the Explosive World War II Drama

The body count is high, but hope is still alive in the trailer for Christopher Nolan’s highly-anticipated World War II drama Dunkirk (in theaters July 21). The historically-based action thriller tells the story of the nearly 400,000 Allied troops who were stranded on the coast of France and surrounded by German forces in May and June of 1940.

Thanks to a daring evacuation effort by the British army involving hundreds of private vessels, over 330,000 soldiers were rescued, an event that was later nicknamed the “Miracle of Dunkirk.” The trailer features Cillian Murphy as a traumatized soldier enlisted in the rescue effort; Kenneth Branagh as an English commander; Mark Rylance as a civilian boat captain; Tom Hardy as a fighter pilot; and One Direction bandmate Harry Styles (in his film acting debut) as one of the stranded troops. The gritty film was shot on location in Dunkirk, France — check out behind-the-scenes photographs here — and Nolan is so dedicated to authenticity that he refurbished actual WWII-era battleships to use in filming. (Rumor has it that he also purchased an authentic German Luftwaffe aircraft for $5 million dollars just to destroy it in a battle sequence, but take that one with a grain of sea salt.) Watch the first trailer above.

Related: Christopher Nolan’s WWII Drama ‘Dunkirk’: On-the-Set Photos Posted From France