Fairfax, Yvette, Edith, Kurt, René, Carstairs and Michelle are all performing their dance on stage, clad in dresses (of which René happens to drop his skirt). Meanwhile, Hubert drives the refuse truck to the back of the "theatre" and as they have finished, they go out the backway and all hide inside the truck, where Helga awaits them. As they drive out of the camp, herrs Flick and Von Smallhausen break through in the tunnel and come out in hut where it ends. When they try to leave by the camp gates, the guards do not believe they are Gestapo agents and therefore, they leave the camp by the tunnel.
When the engine of the refuse truck dies down, the gang all go out to stretch their legs. It is then discovered, that the airmen did not stay behind as they were supposed to but have come with them. When they have all returned to the café, everyone can dress in their ordinary clothes - except for the colonel, who has to hide in the cellar, still dressed in a dress, until they have brought him a German uniform of some sort. As Edith brings him food, René and Yvette have a little cuddle in the café - interrupted by Gruber, who arrives with a uniform for the colonel. While he goes down the cellar with it, René, Edith and Yvette have a rendezvous with Michelle in the backroom. She informs them of why Maria was not with them when they escaped. Apparently, she came up with her own escape plan and disguised herself as a Red Cross parcel, but did not put on enough stamps and was hence sent back to Switzerland. They light a candle and have a few silent seconds for her, after which René points out they shall have to advertise for a new girl. Once they have assured Michelle that the airmen are there (hidden under the table in the backroom), they go upstairs to await London's call on the radio.
Herrs Flick and Von Smallhausen have brought a radio device and a big battery to the roof of the chateau, where they will jam the signal from London. Meanwhile, the café gang and Michelle find Fanny sleeping in her bed, but René harshly wakes her up. As the bedknobs start flashing, they also discover officer Crabtree in her bed, with bandages on his head. It turns out he hit his head while crawling through the drain pipe and Fanny let him sleep in her bed to get some rest. As they are going to talk to London, the Gestapo agents jam the radio and broadcast themselves instead, claiming to be "London calling". Herr Flick tries to lure "Nighthawk" into giving him the names and addresses of the resistance, but in vain, since René does not know them. As the café gang thinks it sounds suspicious, the Gestapo agents try to convince them they are calling from London, by making sound effects, supposedly coming from Piccadilly Circus (car horns honking, news criers, flower girls calling "lovely violets" etcetera). However, Von Smallhausen slips off the roof and as he does so, he shouts "Herr Flick, I'm falling off the roof!" right into the microphone - making the café gang discover it is the Gestapo agents. Since they have been "discovered", René throws the radio out the window in panic, breaking it. Michelle points out they have not been discovered, since herr Flick does not know their position. However, it is too late, since the radio has already been thrown out.
Colonel Von Strohm and lieutenant Gruber enter the café, wondering what has become of captain Geering. Helga enters the café giving the colonel Hans's glasses, which was all she found after searching the vicinities of the camp. When the café gang comes downstairs and discover the Germans, René is wondering if they find it suspicious that he has been upstairs with his wife and the policeman, but they do not - "in France, I'm not surprised at anything" says the colonel. Crabtree leaves, but the next moment, Michelle comes downstairs, disguised in René's hat and coat. He claims she is the "gas inspector" and quickly hurries her into the kitchen. There, Edith comes up with a plan of how to contact London for the moment - by diverting the Germans and getting into Gruber's little tank (in which there is a radio transmitter). René is hesitant of the idea, but soon gets other things to think about. The colonel wants to speak to him and monsieur LeClerc, whom René had sent across the square to buy more gin, comes staggering into the café with the bottles. He explains he passed out in the bushes for some time, since he was hit on the head by a falling radio.
As René finally sits down to talk to the Germans, it turns out that Hans has probably been captured by the communist resistance. However, he cannot talk to them for long, since he, Edith and Michelle are to use the radio in Gruber's tank. They need a diversion for the Germans, but reject LeClerc's suggestion of him performing his famous knife throwing act blindfolded. However, Edith asks Gruber to play something on the piano and René acts emotionally struck, needing to go outside for a while. When they get out to the tank, Michelle is already there and the radio is ready for them to use - they just need a higher aerial, which she fixes by throwing the aerial cable, attached to a rock, into the bathroom window on the second floor of the café. After she has left, René and Edith go into the tank and manage to get in touch with London. However, Crabtree passes by and hears sounds from the tank. He goes into the café and asks for the owner and when Gruber says he is the owner informs him of the sounds. Therefore, Gruber, Von Strohm and Helga Geerhart go out to the tank, just as René and Edith are getting out of it. They try to explain they heard the telephone ringing and answered it for them.
A voice can be heard on the radio and as the colonel answers, it turns out to be Hans Geering. They were quite right in assuming he was captured by the resistance, but as he was mistaken for a British airman, he was sent to England. He is now in an office overlooking Picadilly Square (the same sound effects as Von Smallhausen was making earlier can be hard, but this time, more realistic and credible). Von Strohm orders him to escape and return, but Hans says that will not be easy - since he does not have his glasses. He signs out saying the war is over for him. Very downhearted, the colonel walks away from the tank.