While the film is shown in a nonlinear narrative, including the action of one week on the beach, one day in the rescue flotilla, and one hour of the air battle, the following is the chronological order of events that happen in the film. In 1940, during the
Battle of France,
Allied soldiers retreat to
Dunkirk. A British soldier named Tommy loses his squadmates and flees through the perimeter held by French troops to the beach, where thousands await
evacuation. He helps another soldier, Gibson, bury a body and survive a
Luftwaffe dive-bomber attack. They rush a wounded man on a stretcher onto a hospital ship at the single, vulnerable
mole, overseen by Commander Bolton, available for embarking on deep-
draft ships, but are ordered off again before the ship is sunk by German aircraft. Tommy saves a
Highlander, Alex, from being crushed by the wreck. That night, the three board a
destroyer, but it is hit by a
U-boat torpedo before it can depart. Gibson saves Tommy and Alex as the ship sinks, and they return to the beach. The
Royal Navy requisitions civilian vessels in England for the evacuation. In
Weymouth, civilian sailor Dawson and his son Peter set out in his boat
Moonstone, rather than let the Navy commandeer her. Their teenage hand George joins them on impulse. In the
English Channel, they save an officer, now
shell-shocked after surviving a U-boat sinking. Realising Dawson is going to Dunkirk, the officer grows fearful and Peter locks him up. He escapes, urging they turn back, and tries to wrest control of the boat; in the scuffle, he elbows George, who falls down a staircase and suffers a severe head injury. Three
Royal Air Force Spitfires fly towards Dunkirk to provide cover for the evacuation, limited to one hour of operation by their fuel supply. They engage in a
dogfight with a
Messerschmitt Bf 109. After shooting it down, one of the pilots, Farrier, has his fuel gauge smashed by another fighter. He and the second Spitfire pilot, Collins, determine their leader has gone down and fly on with Collins radioing Farrier about their remaining fuel. The crew of the
Moonstone witness the two RAF pilots protect a
minesweeper from a bomber escorted by fighters: Collins's Spitfire is hit and he
ditches. Initially trapped in his canopy as the plane sinks, Collins is saved by Peter. Becoming increasingly desperate, Tommy, Alex and Gibson join Highlanders in a grounded trawler in the
intertidal zone outside the perimeter, hoping the tide will float them home. After its Dutch sailor returns, Germans start shooting at the boat, and water enters through the bullet holes. Alex, attempting to lighten the craft, accuses Gibson, who has been silent the entire time, of being a German spy despite Tommy's pleas. Gibson reveals he is French, having taken the identity of the buried soldier in hopes of being evacuated earlier. The tide finally lifts the trawler but the group has to abandon the sinking boat. Gibson is entangled in a chain and drowns. Farrier engages a German bomber, knowing his fuel is running out, but the destroyer is bombed and sinks.
Moonstone manoeuvres to save men in the water; one of the rescued men points out to Peter that George has died of his injuries. Farrier shoots the bomber down; its crash ignites oil on the water, but Tommy and Alex are saved by
Moonstone. Farrier reaches Dunkirk just as his fuel runs out and shoots down a dive-bomber approaching the mole before gliding onto the beach beyond the perimeter where he is
captured. Dawson has
Moonstone evade aerial attack, using a technique taught by his deceased elder son, a pilot lost at the start of the war. With 300,000 men successfully evacuated, Bolton stays to oversee the French evacuation. The officer and Collins part ways with the Dawsons, as Peter fulfills George's desire to do something that would make the newspaper, by arranging publication of a eulogy. Tommy and Alex board a trainload of evacuees and are heralded by the public at
Woking, as Tommy recites
Churchill's address from a newspaper. == Cast ==