Part of the café gang (René, Edith and Yvette), Michelle, the German officers (Kurt and Hans) and the two British airmen (Carstairs and Fairfax) are all trapped inside the Stalag Luft IV prisoner of war camp. While the German officers and the airmen participate in a game of cricket to keep themselves occupied, Edith and Michelle are digging their way through the caved in tunnel. René has the task of disposing of the dug up earth from it. He also manages to notify Yvette and the officers that the escape committee will soon be having a meeting. The colonel happens to hit the ball too far and break the German commandant's window - which is why he stops the game. When he breaks one of the cricket gates in two, Hans gets angry and stomps on the other gate. These stomps are heard underground - where herr Flick and Von Smallhausen are digging a tunnel into the camp to investigate.
Back at the café, Fanny and monsieur LeClerc are running the bar, when monsieur Alfonse enters, to urgently speak with Fanny. After some time, when he has found out she has got neither her ear trumpet or her spectacles, he writes down his message and makes her read it by looking through a glass filled with gin (making it a magnifying glass). This way, he informs her that René has been imprisoned, but she has no idea of how to get him or the others out.
Some of the British prisoners are having a meeting discussing escape plans, together with the airmen and Michelle. She then explains the plan to René, Yvette, Edith and Kurt. The idea is to put a barrel near the barbed wire fence of the camp, put a plank over the barrel and then let somebody stand at one of the ends of the plank, while somebody else jumps on the other end - projecting the first person over the fence. They decide Hans will be the one to be sent over the fence and René will be then one to jump - from the roof of the nearest hut.
Hubert is sitting at the café, not enjoying Fanny's song, when Helga enters, disguised as a nun. She informs him that the officers - and René - are held prisoner in the camp. She has a plan for rescuing them, but requires Hubert's help - which he offers without hesitation. Before she can continue, officer Crabtree enters the café. He approaches monsieurs Alfonse and LeClerc with his own rescue plan.
In the camp, the plan is carried out. Yvette and Edith help René on the roof and his trousers are filled with earth, to make him extra heavy. Before he jumps, Kurt and Hans go through their own plan, which is for Hans to get Gruber's tank, squash the fence and get the colonel out. The first time René jumps, Hans is not sent flying into the air, because the plank breaks in two. The second time (when they have produced a stronger plank), Hans goes up, but lands on the hut roof. The third time, they manage to get him out to the other side of the fence, where some resistance girls show up and take him with them.
Meanwhile, the different escape parties approach the tent. Helga is dressed as a woman of loose virtue, while Hubert is dressed as a nun. They have a pram with a gramophone inside it with them. As Helga distracts the guard into the camp (by showing her legs and playing Lili Marleen on the gramophone, he is more than willing to let the nun in "to distribute some religious pamphlets" in the camp. Meanwhile, Crabtree, Fanny and monsieurs Alfonse and LeClerc arrive outside the camp.
Herr Flick and Von Smallhausen check out, if they are under the camp, by sticking herr Flick's Gestapo telescope up through the ground. Herr Flick happens to stick it up right between Gruber's legs, but thinks he is a nun. Gruber has entered the camp and finds Edith outside a hut. She is surprised to see him, but shows him in, where he informs her and the rest of the gang of his and Helga's rescue plan. He will drive the refuse truck into the camp and they will all jump into it, whereupon he will drive it out again. They agree to persuade the prisoners to create a diversion. When Gruber has left, they are driven out of the hut to exercise.
Meanwhile, Fanny has been put to steer a crane, which is standing at the roadside, because some drain pipes are being laid down at the moment. She lifts one of the pipes - inside which Crabtree is hiding - over the fence. René, Edith and Yvette spot her and go to see what is happening. As they talk to Crabtree and learn of his rescue plan, they tell him they already have another plan. Therefore, he and the others cancel their plan and go home. Meanwhile, the commanding officer of the prisoners informs Michelle that they cannot make a diversion that same night - because they will perform a stage play rehearsed for weeks then. In order to still take advantage of this, it is decided that the airmen, Kurt, Michelle and the café gang will also participate in this stage play.
That same evening, Gruber comes into the camp, driving the refuse truck, while the play is under way. When the commanding officer has performed a number, he presents "the lovely ladies from hut four: Les Girls", whereupon the café gang, Michelle, Kurt and the airmen dance on the stage - all dressed as women. The colonel spots general Von Klinkerhoffen in the audience, but there is nothing to do - they just have to keep dancing and hope they are not discovered.