The Colonel orders Mainwaring and the platoon to make a training film with a couple of well known actors but unknown to Mainwaring they are to play the Germans. Mainwaring refuses to take part but the rest of the platoon are ordered to. When the filming is cancelled Mainwaring and the men still dressed as German soldiers are spotted in the local pub and the alarm is given.

Pike finally gets his call up papers and is to join the Airforce but when his blood that has been donated for the red cross is checked it is found to be from a rare group and he is excused military service Then he has to find a way to break the news to the platoon

Godfrey's cottage is due to be demolished to make way for a new airfield but no-one can bring themselves to break the news to him until Jones finds out that he already knows. In the end Frazer, knowing the family history of the General in charge, bribes him to get the airfield moved 200 yards. This results in some rather amusing consequences. The door to Mainwaring's bank office is replaced with a paper door, apart from the insult of not having a proper door Mainwaring is even more annoyed at the fact that Pike the Colonel and Jones manage to destroy it within minutes of it being installed.

Captain Mainwaring gives a lecture on field craft in the vicar's garden, covering what to eat and how to erect a tent. Later, apart from having to put with the vicar, verger, Hodges and a gang of boy scouts, their field manoeuvres are also interrupted by three German fliers who have been shot down and are trapped in their dinghy in the middle of the lake... ""Handi hoch! Handi hoch!""

Cpl Jones has problems with his bank account. When Mainwaring tries to help, he finds that the trail leads through the platoon, on to Mrs Pike, and ends with Mr Hodges.

Mainwaring has visions of promotion for himself and Wilson and of expanding the platoon into a company, so he embarks on a recruitment drive. A poster is drawn up and Jones is voted to be in it. Unfortunately a mix-up at the printers results in Jones being branded an escaped prisoner of war instead.