Fionn Whitehead, Mark Rylance and Kenneth Branagh head the cast of Christopher Nolan’s overwhelmingly immersive epic about the Dunkirk evacuation.

This is a far from conventional war movie, though. Don’t expect to see any Hollywood heroics, or traditional scene setting, for that matter.

Instead, we are plunged directly into the thick of things, thrust into the midst of the race against time to rescue hundreds of thousands of Allied troops from the beaches of northern France in the early summer of 1940.

From the start, Nolan gives the action a terrifying immediacy, pummelling us with the intensity of his images and the throbbing power of Hans Zimmer’s score.

This puts us right there in the shoes of Whitehead’s teenage soldier on the beach, at the helm of Rylance’s small boat as it crosses the Channel to help the rescue effort and in the cockpit of pilot Tom Hardy’s Spitfire. Nolan interweaves these narrative strands brilliantly, giving us a series of incredibly suspenseful micro-dramas to convey the panic, terror, endurance and resolve of the people involved.

No one gets a traditional narrative arc, a back-story or a loved one waiting anxiously at home. And no one gets to make a heroic speech, not even Branagh’s stoic Naval officer in charge of the evacuation. There is so little dialogue that Dunkirk almost works as a silent film, which may jar with viewers anticipating a more orthodox war movie.

The film does, however, find room for Harry Styles, who acquits himself credibly as one of the troops, while reminding us just how young these scared, stricken, resilient soldiers were.