When the bed with the bride and groom has been pulled out of the church by the bridesmaids, Monsieur Alfonse takes a picture of the entire café gang against the church wall. Then, the bed is pulled away, attached to the hearse. While rice is thrown over the bridal couple, Fanny throws the bridal bouquet, which is caught by Gruber.
Von Smallhausen comes into Herr Flick's headquarters, dressed as a boy scout. This is so he has been able to get into general Von Klinkerhoffen's quarters, since it is "bob-a-job week". While cleaning in there, he has managed to acquire a map to the position of the mines under the town.
At the reception, Michelle informs René and Edith that when it is over, a big basket will be brought into the marquee to collect the garbage. However, this basket will be attached to the balloon and the airmen will travel in it. When the Germans arrive, the inform René that there is now a 500 pound bomb in the sewer under the café. As there is nothing that can be done about it at the moment, the reception continues. René, being the best man, starts the speeches by holding one himself. After this, he calls upon the groom to hold one to thank the bridesmades. This does not go very well, but at least, this makes them ready to cut the wedding cake. As Fanny and LeClerc are doing this, Mimi comes up behind René and Edith telling them, that she has been to the cellar and that the bomb is in there, not in the sewers. As the helium containers (which are placed under the table that Michelle, Edith and René are sitting at) start to leak, some of the resistance girl get down to try to stop the leaking. In order to cover this, Monsieur Alfonse starts to play a song on his accordion. Edith sings and soon, the whole marquee falls in. However, due to the leaking helium, everybody's voice becomes high-pitched and squeaky.
Herrs Flick and Von Smallhausen crawl through the sewers and find a mark-nine mine. Von Smallhausen starts reading "The Gestapo Handbook on the Defusing of Detonators", but as he tries to defuse the bomb, he accidentally sets off the timing mechanism. Herr Flick therefore withdraws outside the sewers and keeps in touch with Von Smallhausen via radio. Von Smallhausen manages to remove the detonator, so it cannot set off the main charge, but when he is about to render the detonator harmless, it produces a small explosion anyway.
René and Edith go down the cellar and find the bomb. They then decide that René will make an anonymous phone call to the general's office to give the airmen up. Edith goes back to the wedding and René picks up the telephone to make the call. He is however stopped before he can do it - by Louise (formerly second in command, now the leader of the communist resistance). She tells him that the bomb in the cellar was placed there by her people as part of their plan to save Nouvion. She demands that he get the colonel inside the café. When he has done so and Louise and her girls capture the colonel, he is very disappointed at René for having betrayed him. René tries to explain that it was at gunpoint. The next moment, somebody is approaching the café and the girls hide with the colonel. As it turns out to be Herrs Flick and Von Smallhausen who are coming, the resistance girls capture them too. The three of them are brought down the cellar and tied to the bomb.
At the German headquarters, Gruber and Bertorelli are wondering what has become of the colonel. The next moment, general Von Flockenstuffen arrives and also wonders about the colonel. Secondly, he wonders if general Von Klinkerhoffen is serious about blowing up the town. As the Germans are discussing this, René shows up, in his underwear, with his wrists tied together between his legs. He gives the Germans a note from the communist resistance, saying that Von Strohm, Flick and Von Smallhausen are tied to a 500 pound bomb and if the town is blown up, so will they be.
In the cellar, Herr Flick notices that the bomb is attached with wires to a clock on the wall. As Von Smallhausen manages to untie a knot, he manages to hop over to it and is made to keep the big hand of the clock still with his nose.
When general Von Klinkerhoffen arrives at the German headquarters, he is informed of the colonel's and the Gestapo officers' predicament. However, he says this makes no difference. He says, in a more and more angry voice, that his patience has been tried to the limit and finally, he loses his grip, since his nerves are overworked, and he starts laughing at absurd memories and blow things out of proportion. General Von Fluckenstuffen then calls the military hospital - "fruitcake department".
When René has returned to the reception in the marquee (from which the guests have now left), the big basket is brought in by Crabtree and Grace. As the helium uncontrollably starts leaking into the balloon, it grows into full size, knocking over the marquee. In order to keep it from floating away, everybody helps tying it to the bed. However, this makes the bed, with Fanny and Ernest in it, float away, up through the air.
General Von Klinkerhoffen (whom Von Flockenstuffen calls "Piggy") is dressed in a white hospital gown and placed in a hospital bed. He fights this and especially when he is to be given a sedative, claiming that he is just as sane as everybody else. However, when he sees the bed with the bride and groom floating by outside the window, he is not so sure anymore and agrees to have the sedative.