*CUT TO THE CHASE*
NOTE: This spoiler was submitted by Jeremy
The film alternates between three different periods of time involving separate groups of people leading up to their encounter at Dunkirk, and as such, the film follows a non-linear narrative.
The opening text reads that the British and French armies during World War II have soldiers stranded on Dunkirk as they wait for the miracle of a rescue, or until they die.
1. The Mole (One Week)
Six British soldiers are walking through the desolate streets of Dunkirk. They are looking through abandoned houses for supplies when they are fired at by German soldiers. Five men are killed except for one, Tommy (Fionn Whitehead). He escapes the gunfire and makes it to the beach where hundreds of soldiers lay dead. Tommy tries to find a spot to relieve himself when he sees a young soldier, Gibson (Aneurin Barnard), burying another soldier in the sand. Tommy goes over to help him.
The other soldiers look up as German planes fly overhead and start dropping bombs. Many men are struck, and Tommy prepares to go down as well, but the bombs miss him.
Tommy finds a wounded soldier left for dead. He and Gibson pretend to be medics to carry the soldier onboard the ship tending to the wounded. They pass a group of French soldiers trying to get on but are being denied entry under orders. Tommy and Gibson do not make it onto the boat but manage to hide out by the mole (the concrete structure separating the water) until the next vessel shows up for them. The boat they're waiting for is attacked and sunk, but they save a soldier named Alex (Harry Styles).
Commander Bolton (Kenneth Branagh) of the Royal Navy and Colonel Winnant (James D'Arcy) are standing by the docks to negotiate the rescue and safe return of the soldiers. They opt to use boats to bring them back.
The soldiers all gather on the vessel. They get a little bit of food and water. Alex meets Tommy and notices Gibson walking around looking uneasy. The enemy then hits the ship with a torpedo, causing water to burst in quickly. As the ship sinks, Gibson gets out of the ship and manages to open the hatch for Tommy, Alex, and a few other men to get out safely. They board a skiff back to the shore.
Back on the beach, the surviving British soldiers join up with with Scottish soldiers heading to a boat within the tide. The British soldiers hide in there, but since they are technically on German land, they soon get hit by bullets from German soldiers using the boat as target practice. The bullet holes start to bring water in. Alex suggests they throw Gibson out to lighten to boat, going so far as to accuse him of being a German spy since he hasn't spoken the whole time, possibly to disguise his accent. Gibson reveals himself to be French and that he took the uniform and tags off another soldier (the one he was burying). The boat starts sinking. The soldiers make it out, except for Gibson, who gets caught on something and drowns.
2. The Sea (One Day)
The Royal Navy starts taking over private boats in an effort to rescue the soldiers. A mariner named Mr. Dawson (Mark Rylance) takes his own ship with his son Peter (Tom Glyne-Carney) as opposed to allowing naval officers to commandeer it themselves. The two are joined by their young helper George (Barry Keoghan), who assures Mr. Dawson that he can be of good use to them.
The boat passes a sunken British ship. They find a shell-shocked soldier (Cillian Murphy) in the water. Mr. Dawson asks his name, but the soldier is silent. George tries tending to him with some tea, but the soldier knocks it out of his hand. The soldier asks Mr. Dawson where they are headed. He tells him Dunkirk, and the soldier is fearful of going back there. He tries to take control of the boat from Mr. Dawson, and the ensuing struggle leads to George falling to the bottom of the boat and hitting his head hard. Peter goes to tend to his wounds. George gradually starts to lose his sight. Peter tells his father, but Mr. Dawson says they have come too far to turn back for help.
3. The Air (One Hour)
Three Spitfire pilots fly over the sea to provide air support to the troops. The squadron leader, plus pilots Farrier (Tom Hardy) and Collins (Jack Lowden), spot German planes in the sky and go after them. One of the Germans shoot down the squadron leader, leaving Farrier and Collins up there on their own. Farrier's fuel gauge is broken, so he does his best to preserve fuel and take the enemy down.
Collins' plane is shot down and he heads down to the water. He tries to break himself free but the water is pouring in and he is stuck. Nearly resigning himself to his fate, Collins is broken out by Peter, as his father's boat has managed to find the plane. They bring Collins onboard. From his conversation with Mr. Dawson, we learn that Peter's older brother was a pilot who died in the early weeks of the war.
By this point, all groups come together on the waters.
More private British boats show up on the waters to rescue the soldiers. The soldiers spot a minesweeper and head toward it until it is hit by one of the German bombers. The water fills with oil as the soldiers swim past it and get covered in it before it is ignited, killing several men. Farrier manages to shoot down the bomber as he runs out of fuel and heads toward the beach to make a safe landing. Mr. Dawson pulls Tommy, Alex, and a few other men onto his boat. Alex points out to the Dawsons that George is dead. The shell-shocked soldier, unaware of this, asks Peter if George will be okay. Peter lies and says yes.
Farrier lands his plane slowly by the shore. He sets his plane on fire and is soon captured by German soldiers.
The Dawsons return home following the rescue. Peter gets a picture of George and takes it to the local paper so that the boy may be remembered as a hero.
Bolton and Winnant mention having saved 300,000 men after only planning to rescue 30,000. Bolton stays to make sure the French can evacuate.
The soldiers are sent home on a train. Alex thinks that they will be met with scorn upon returning for failing to win. He sees a newspaper with a message from Winston Churchill regarding the evacuation and asks Tommy to read it. As Tommy reads it upon entering the station, a man approaches the window and hands Alex two beers. Other people welcome the soldiers back with applause. Tommy finishes reading Churchill's statement which mentions the bravery and efforts of the soldiers.