Alma shows Prewitt a newspaper article about Judson's death—no one knows who the killer is. Prewitt is getting drunk.
We see soldiers eating in the mess hall, when they see planes flying in. They also hear explosions and think it's dynamiting exercises.
Suddenly the explosions are much closer and a plane guns down a soldier running across the field towards them. The Japanese are surprise-attacking the base at Pearl Harbor.
Prewitt hears about it on Alma's radio.
Warden tells the soldiers to get their rifles and go to their bunks to avoid getting killed by the planes.
The attack continues—we see the Japanese destroying ships and planes.
The soldiers try to get ammunition, but the soldier in charge won't give it to them because he doesn't have orders. Warden forces the door and seizes the ammo. Bombs keep falling.
Warden decides to rush outside and try shooting down some planes. We see more battle footage—ships explode, soldiers are strafed.
Warden leads some soldiers outside to attempt to shoot down planes with machine guns and even their rifles. They finally hit one and it goes down, exploding. Warden and another soldier celebrate.
Prewitt hears more about the attack by radio. He decides he needs to rejoin the other soldiers. Alma tries to stop him, but he heads outside—he loves the army too much. Alma says she'll marry him—anything if he won't go. But he goes.
Prewitt tries to rejoin his comrades, but soldiers shoot him, mistaking him for a Japanese paratrooper. He dies.
As the soldiers examine his body, Warden comes over. He says that Prewitt loved the army more than any soldier he ever knew, before instructing the soldiers to move his body.
Finally, we see Alma and Karen on a ship leaving Hawaii. Karen drops leis (flower garlands) into the ocean, and says that there's a legend—if the leis float to shore, you'll come back. If they don't, you won't.
Alma says she won't come back—her fiancé died during the attack. She claims he was a bomber pilot. When she says his name, "Robert E. Lee Prewitt," Karen recognizes it but doesn't say anything.
In the movie's final frame, we see the leis floating away, though we don't know where they're headed.