René is peeping through the key hole in the door to the backroom, where Madame Lenard is modelling some lingerie for Edith to wear on their wedding night. Suddenly, Edith comes out of the room and the next second, Yvette comes in through the front door of the café, reporting that Maria has been arrested by the personal guard of General Von Klinkerhoffen. As she is carrying the sausage with the real painting around her bosom and she may reveal certain things under torture, René decides to escape to his cousin in Bordeaux. As Edith forces him at gunpoint to stay, Hans and Kurt enter the café. They say Herr Flick is looking for his sausage and ask René if it is still safe in his cellar. He explains to them that Gruber threatened to drive his tank through his café, if he would not hand it over to him, but he also informs them that was to give the real painting to Gruber, in order for him to make a copy of it. Secondly, he tells them that Maria has been arrested and that the sausage is now in the hands of the general.
Maria is brought to General Von Klinkerhoffen to be interrogated as to why she was "snooping" around the chateau. As she says she had a rendezvous with lieutenant Gruber, the general sends for him. Meanwhile, he orders her to take off her hat and coat, which she is reluctant to do. As Gruber enters the room and does not confirm that he was to meet Maria, she reveals the sausage to the general, who places the sausage in the wardrobe in his dressing room to mature and to stop the kitchen staff from eating it. As Gruber is about to leave, the general orders him to let it be known that he will release Maria, when his lawnmower engine is returned. He then orders her into his bedroom, to lie down on his mat.
When Fanny, in her bed, cries for somebody to come to her aid, Edith comes up to her and tells her she has chosen some lovely things for her wedding night. Fanny thinks she will marry monsieur Alfonse, but she tells her she will marry René, because she loves him. However, they do not know where he is hiding from the Gestapo at the moment, but when the bedknobs start flashing, it turns out that he is hiding in her bed - disguised as an old woman. As he will not help Edith to get the radio out, she asks the airmen (who are now hiding in the cupboard) to help her. As she gets in contact with London, it turns out the airmen's commanding officer, Hargraves, is on the line, wanting to talk to them. He asks if they will be back soon, but when they inform him of the plan with the museum airplane and the lawn mower engine, he has not got big hope of it. When they have signed out, Yvette comes in and tells them the police are here. The airmen quickly hide again, but it only turns out to be officer Crabtree. He has come to arrest Fanny, since she has been passing forged bank notes in the hat shop. When he asks "the bog in your mither's bed" is, René reveals himself to him.
Herr Flick is showing Helga a roll of film, taken at last year's Gestapo holiday camp, when Von Smallhausen reports by telephone that the sausage containing the painting is hidden in the general's wardrobe. Herr Flick then comes up with a plan to substitute the real knockwurst for an empty one. Helga is to create a distraction for the general, while Herr Flick switch knockwursts.
Monsieur LeClerc enters the café, disguised as an Italian organ grinder. He tells René and Edith that Maria is being held hostage until the engine is returned and that the sausage is hanging in the general's wardrobe. When he has left, Yvette informs them that Michelle is waiting for them in the backroom. As they come in, they find her hiding under the table and therefore, they all hide under the table while she is about to tell them the plan for stealing the airplane from the museum. However, they inform her of Maria's predicament and that they must rescue her. Edith comes up with a plan, since she knows all the secret passageways in the chateau after having been a serving maid there when she was young. Meanwhile, Gruber tells the colonel and the captain about the situation and the come up with a plan to switch sausages, while Gruber distracts the general.
Edith explains their plan to Yvette. She will be dressed as a serving maid and bring the general a hot water bottle. While in his bedroom, she will distract him and also give Maria a little note about a secret passage, while Edith and René switch sausages in the wardrobe in the dressing room.
That same night, the general orders up some snacks to his room. Meanwhile, Edith and René enter the chateau through the secret passage ways. They come out through a big cupboard. After avoiding being spotted by a guard, they sneak up the stairs. The colonel and the captain also enter the chateau through the secret passage ways, after knocking down another guard. Herr Flick is hiding inside a medieval suit of armour, also sneaking around the corridors. As he approaches the place where Edith and René are looking for a knob to open another secret passage, they are forced to hide and the only place René finds to hide is on the lower shelf of a food trolley, which a soldier delivers to the general's bedroom, outside which Herr Flick is standing in his armour. The general does not want anybody to find out he is having a French girl in his room and therefore forces Maria to hide in a cupboard inside his bedroom (not the one in his dressing room, where the knockwurst is hanging). While the soldier is discussing the snacks with the general, René manages to switch the sausages and quickly hides on the trolley again, before it is rolled into the general's bedroom, after which Maria is allowed to come out of the cupboard. However, she is soon forced into it again, when Yvette (disguised as a maid) turns up with a warming pan to warm the General's bed. René manages to sneak out from the trolley and hide under the bed, just as Yvette places the warming pan there and Edith pops up out of the commode next to it. Yvette starts stripping for the general, just as Helga knocks on the door, bringing a present from Herr Flick. The general makes Yvette hide under the bed, where she finds René. Helga puts the gift (a gramophone) on the general's table and starts a striptease to a raunchy music version of the German national anthem. Meanwhile, the colonel and the captain enter the dressing room to switch sausages, but are delayed with peeping through the keyhole of the door to the general's bedroom. While they are doing this, Herr Flick swaps the sausage hanging in the wardrobe for his own and leaves. Then, the colonel and the captain swap their sausage for the one in the wardrobe and also leave. While Helga is stripping on the bed and the general is sitting with her, René manages to move from underneath the bed to the cupboard where Maria is hidden. Having gone through the secret passage ways, Edith turns up in the same cupboard, and all three escape down a secret passage. Back in the bedroom, Gruber turns up with a bottle of whisky, in order to do his distraction for the general, who thinks he can take advantage of Yvette, while he takes advantage of Helga.
- Gruber: "Oh dear, is there anything I can do?":Von Klinkerhoffen: "Yes, wind up the gramophone and enjoy yourself. And if you do not fancy that one, there's a spare in the wardrobe."