René is sitting in the backroom, removing his disguise mask, when Yvette announces Michelle. She brings Crabtree's uniform and says they have told him to come here, since he cannot go to the police station in his present state. The next moment, Crabtree comes out of a cupboard in the room, dressed in a dress and the big ears. When they have given him his uniform and sent him upstairs to change clothes, Michelle informs René and Yvette that her people have dismantled the aerial and the radio in the graveyard and assembled it in Fanny's bedroom instead. When Michelle says the must go there to send a message to London and René says he will not do it, she forces him at gunpoint.
Fanny and Edith are sitting on Fanny's bed, talking about the materials to be used for the clothes for the wedding, when Michelle, Yvette and René enter the room. Michelle operates the aerial with a few switches installed in the cupboard. Firstly, the bed folds in half to make room for the aerial. Secondly, the roof opens up and thirdly, the aerial rises out of one of the bedposts. When they have sent the message ("The cow is ready to jump over the moon and Jack and Jill are standing in a bucket"), Crabtree shows up, complaining to Michelle that he cannot unglue his false ears. She then gives him a removal for this. When he has gone, it starts snowing through the opened roof, down on the bed. When Michelle lowers the aerial, to be able to close the roof, there is a big bird sitting on it, which they have to get rid of first.
At the chateau, general Von Klinkerhoffen is complaining that the plan failed utterly. Captain Bertorelli tries to defend himself by saying that his men did exactly as they were told and colonel Von Strohm blames lieutenant Gruber for bringing poodles instead of bloodhounds - borrowed from French tarts, as the general puts it. The next moment, a guard enters the room telling them, that two British airmen have been picked up. When they are brought in, they turn out to be Herrs Flick and Von Smallhausen. The inform the rest of the Germans, that they have made contact with the resistance and that they should arrest the persons fitting the description of the disguises the café gang had at the old castle. They do not recognize any of these people, except possibly the witch, which resembles madame Edith. The general thinks they are trying to pull their legs and says they will be kept under close observation and "Berlin will be informed of your perverse antics and your acalcitrous demeanour, which has exacerbated the quid pro quo, vis-à-vis interdepartmental relationships." The Herrs leave, with Herr Flick saying "Come Von Smallhausen. To our dictionaries."
When they have left, Helga enters the room saying there is a message for the general on the telephone. Gruber takes it, but when he informs the general of the message that has been picked up (about the cow and Jack and Jill), he thinks the Gestapo has sabotaged their radio station. When he is told that Helga and Herr Flick are keen to get married (or at least Herr Flick is), he comes up with a plan to keep Herr Flick under observation. Helga will marry him, report everything she finds out back to the general and then, when they have enough information, he will have the Führer annul the marriage.
In the backyard of the café, Ernest brings some sandwiches for the two British airmen. In one of them, they find a note with the message "anal ... ubmarine". They interpret this as Michelle wanting them to go down the canal to meet the submarine. In their wetsuits the head toward the canal under their tin bath.
In Helga's room, she is preparing herself to seduce Herr Flick. Gruber comes in with some champagne and some caviar and instructs her of the plan. When a soldier enters with a vase of flowers, Gruber points out that it is too early. They will be delivered at the sound of the champagne cork popping - seemingly from an admirer - to make Herr Flick jealous. Soon after Gruber has left, Herr Flick arrives. Helga tries hard to seduce him and even proposes to him, but he is rather reluctant. When she tries to open the champagne bottle, she cannot get it open and must therefore make a popping noise instead, so that the flowers can be delivered right on time. However, they do not make Herr Flick very jealous. As she throws the flowers with the vase out the window, he is more concerned that she has hit Von Smallhausen. When she presents him with a ring, he is "most touched", but she has a very hard time seducing him.
Mimi is in the larder cutting cheese for the Germans to put in their ears when madame Edith sings. René finds time to have a quick cuddle with her, but they are interrupted by Yvette. When Mimi has left with the cheese, René and Yvette also have a quick cuddle. When madame Edith has finished her number, she receives applause, because she has not sung but performed a tap dance. When she is done and René and Yvette come up from the larder, they are all called into the backroom, where Michelle wants to talk to them. She says they must all go to the rendezvous at the estuary to make sure the airmen get away on the submarine. As an excuse, they will disguise themselves as a rowboat team and row on the canal. The secret signal from the submarine will be a radio controlled goose with flashing eyes and smoke coming out of its other end. While she is leaving through the back window, Gruber enters the café and tells Von Strohm and Bertorelli that the general urges them to investigate strange goings-on in the estuary.
The next morning, the café gang and some resistance girls are dressed as a rowing eight and row down the canal. Meanwhile, colonel Von Strohm, lieutenant Gruber and captain Bertorelli are sitting in a small motorboat nearby and cannot get the motor running. Captain bertorelli then starts pushing the boat, like the gondoliers of Venice. The British airmen are walking down the canal under their tin bath and the British submarine is also there, sending out a mechanical goose. The café gang are soon joined by Michelle and Monsieur Alfonse, in his funeral boat. As the goose is approaching them, it starts ringing. Michelle picks up the receiver fitted into its back. The submarine captain asks where the airmen are and Michelle says they are trying to locate them. However, she is forced to hang up when the Germans are approaching. Michelle and Monsieur Alfonse head toward the shore, while the Germans urge the café gang to clear the area, since they are investigating strange occurrences. The submarine crew are wondering what is happening and the captain sends up the periscope - right through the bottom the Germans' boat, which capsizes.
- Gorden Kaye as Rene Artois
- Carmen Silvera as Edith Artois
- Richard Marner as Colonel Von Strohm
- Vicki Michelle as Yvette Carte-Blanche
- Sue Hodge as Mimi Labonq
- Kirsten Cooke as Michelle Dubois
- Kenneth Connor as Monsieur Alfonse
- Richard Gibson as Otto Flick
- John Louis Mansi as von Smallhausen
- Guy Siner as Hubert Gruber
- Kim Hartman as Helga Geerhart
- Arthur Bostrom as Officer Crabtree
- Rose Hill as Fanny La Fan
- Derek Royle as Ernest Leclerc
- Gavin Richards as Alberto Bertorelli (uncredited)
- Hilary Minster as General von Klinkerhoffen
- John D. Collins as Fairfax
- Nicholas Frankau as Carstairs
- David Griffin as the British submarine captain
- Tim Brown as the British submarine lieutenant
- Richard Seymour as the German guard