Willie munches on an apple while running in a field. As he rests, he hears a fighter plane overhead and starts playing war games, pretending to shoot from an airplane. He lies down in the forest as if shot down in flames and is joined by Peter, who jumps down from a tree and joins in the game, pretending to be a parachutist. Peter asks for a bite of the apple, and when Willie refuses the two start to fight. Peter wins, takes the apple and leaves Willie crying. Willie tells him that the apple is dirty and the he could die from germs. He tells him that the British air force drops infected apples over Germany on purpose. Peter asks Willie for a cigarette and matches, but he has none. Willie tells Peter that Donald was able to collect enough jam jars to get nine pence for their return. The two boys chase a squirrel up a tree. They are joined by their friends John and Raymond and start throwing stones to make the animal come down again.

In the barn, Donald and Angela are pretending to be parents, but Audrey complains that she has been left out. She decides to be the nurse after Donald pretends to have hurt himself at work. Angela soon feels excluded by the other two and starts to taunt the boy by calling him 'Donald Duck'. Audrey joins in and Donald is soon crying. The boys kills the squirrel but Peter gets angry when Raymond refuses to lend his knife so that they can cut off its tail. He tries to bully him, but John makes him stop. Raymond is clearly upset by the death of the animal.

Audrey and Angela leave Donald in the barn and push a pram up the side of the hill, declaring their undying friendship for each other. They meet the other boys in the forest and tell them they have built a tree house. They all go to the tree, but the girls then admit that they haven't actually started building it yet. Peter bets Raymond that he can't stand on his head while they count to a hundred. Raymond takes the bet but Audrey helps Peter cheat by saying that there is blood coming from his ear. Raymond stops and Peter demands the knife. John and Peter get into a fight, which Peter wins after knocking him down twice. Peter runs to the barn while the others go back in the forest.

Peter finds Donald still crying. He taunts him for behaving like a baby but then relents when he remembers that Donald's father has been captured by the Japanese. Peter asks him how he got enough jam jars together to get nine pence for the empties. Donald tells him he stole them from the shed where the grocer keeps the empties he plans to return to the company. Peter asks Donald if he has any matches to start a fire, but he says he has none. The siren from the nearby Prisoner of War camp sounds. The boys and girls in the forest hear the siren and hide in a ditch, afraid that the escaped prisoner will find them. They are joined by Peter, who says that Donald wouldn't come with him.

John and Peter go to see if the coast is clear and play a joke on the others, pretending that they have been captured by the prisoner. When they return, the others are furious at the joke. The children leave the forest and arrive at the barn just as Donald starts a fire inside it. They block the door as a joke and soon Donald is trapped inside. By the time they open the door, Donald is no longer able to reach it. Raymond looks on helplessly and is the first to run away when he sees Donald flailing inside. The barn is consumed by the flames and the roof collapses. The six remaining children hide in the fields, and agree to pretend that they were all far away at the time of the fire.