The latest escape plan for the British airmen involves them wading along the canal underneath a tin bath. Herr Flick and von Smallhausen pose as escaped British airmen, hoping to be picked up by the Resistance. The Resistance have built a communication post in René's 'grave', in an effort to get around German jamming of their radio signals. René, Edith and Monsieur Alphonse try it out. Rene gets caught on the aerial and is hoisted above his 'grave'. Lieutenant Gruber sees him and thinks it's the ghost of René's 'twin brother'.

Lieutenant Gruber warns René about a Getsapo plan to pose as British airmen. Meanwhile, General von Klinkerhoffen has decided to adopt a similar plan and orders some of Captain Bertorelli's men to be dropped from a plane dressed as British airmen. The Italians are dropped by parachute. They wander off and get lost. René and the women from the cafe disguise themselves as characters from horror films so that Herr Flick can't recognise them when he and von Smallhausen are brought to the "secret Resistance headquarters".

Herr Flick and von Smallhausen, disguised as British airmen, are arrested by the Germans. Meanwhile, the real British airmen make their way along the canal. They've been told to look out for a goose with flashing eyes and smoke coming out of its tail. René and his staff row out to the estuary to make sure the British airmen get picked up by a waiting British submarine. The Germans have also rowed out to the estuary. The airmen get lost and the submarine leaves without them.

After the plan with the submarine went awry, the British airmen have been captured by the Germans and have been locked in a cell in the château. They'll be transported to Berlin the next day. Gruber gives René the keys to the château and the cell to rescue the airmen because his name could be dropped if the airmen start talking while interrogated. Michelle thinks up a plan involving coffins to rescue the airmen and Herr Flick and von Smallhausen also think up a plan, involving disguising themselves, to get their hands on the airmen.

Herr Flick and von Smallhausen are interrogated by the general for impersonating army officers but released on the orders of Himmler - thanks to Helga. A party of intelligence officers are visiting and the Resistance plan to hi-jack their car,steal their uniforms and that way infiltrate the château to get the airmen out. René and Edith are the reluctant 'intelligence officers' but the plan works fairly well until the couple find themselves handcuffed to the airmen whilst the key to unlock them is in Berlin.

René, Mimi and the two British airmen are still handcuffed together. They make their way to the police station, hoping that Officer Crabtree can free them. The Germans want to sell the painting of the 'Fallen Madonna'. They order René to find them a fence. A meeting is held, with Monsieur Alphonse posing as the fence and everyone else wearing paper bags on their heads. The painting is exchanged for the gold weight from the cuckoo clock. Later, the Germans decide that they'd rather have cash, so René arranges for the gold to be exchanged for forged currency. The swap is made in the church, in the confessional booth. There's a cockup and the Germans inadvertantly pass the gold on to the priest.

General von Klinkerhoffen threatens to blow up Nouvion if the airmen aren't handed over. Fanny and Monsieur LeClerc are getting married. Michelle reveals a new plan to send the airmen back to England. A barrage balloon and tanks of helium will be hidden in the marquee set up behind the café for the wedding.

One of the bombs which General von Klinkerhoffen plans to use to blow up the town is hidden in the sewer under the café. Colonel von Strohm, Herr Flick and von Smallhausen are trapped by the Communist Resistance and tied to the bomb. General von Klinkerhoffen is declared to be mad and is locked up in the 'fruitcake ward' at the military hospital. General von Flockenstuffen takes command of the district. Fanny and Monsieur LeClerc are at their wedding reception, in bed because they're both exhausted. The helium balloon for the airmen's escape is tied to the bed. It takes off into the air, carrying the bed with it.