The pumping station of the reservoir has been damaged by a bomb with Walker and Godfrey trapped inside. Hodges is determined to overrule Mainwaring's rescue attempt until it's discovered the structure of the building is very unsafe and they draw lots to decide who are going to be the ones to dig the stranded men out. After successfully reaching Walker and Godfrey, the roof caves in and everyone but Jones ends up trapped in the underground bunker that is now filling rapidly with water. But does Godfrey have a solution that is more useful than asking to be relieved?

Vanity swoops through the platoon after Parliament decides that Home Guard members who are not fit for battle must be reassigned to the ARP and ARP wardens that are fit and able should be reassigned to the Home Guard. The platoon obviously doesn't want this to happen so resort to some rather shocking measures to fool the Area Commander into believing the men are suitable staying where they are.

During the journey home after a night at the cinema, Mainwaring comes to the assistance of a clippie after Hodges accosts her. Later Mainwaring dreams of being Napoleon with the clippie as Josephine.

Rumour sweeps through Walmington-on-Sea that Wilson is seeing a young girl. He goes AWOL and is found drunk. It turns out that the girl is his daughter. Meanwhile Walker has taken delivery of pigeons that have been stolen from Trafalgar Square, and has to find somewhere to hide them. Then the platoon assembles for church parade. What could go wrong?

The platoon practices house clearing by using the office, unaware that the vicar and Hodges have got caught up in the action. Later during a live firing exercise the platoon is sent to the wrong map reference. When Jones discovers the mistake he drives to the rescue.

The platoon is given a lecture on the German army but because Frazer keeps on complaining, Mainwaring makes him Acting CO of the platoon. Later, when the Colonel asks the platoon to attend a dinner, Mainwaring has to play the bagpipes.

While Capt. Mainwaring holds a party at his house for the platoon the bank is hit by a German bomb. After guarding the money all night he has to find a way to transport it to the Eastgate branch for safety.

Godfrey asks for a holiday from the platoon in order to help an old girlfriend who runs a farm to bring in the harvest. Recognising it as vital to the war effort, Mainwaring assigns the whole platoon to help.

When Jones arrives at the bank to deposit £500 from local shopkeepers for the servicemen's canteen, he realises his packet contains half a pound of sausages instead of the money.

During an exercise Mainwaring and the platoon have to find a way to gain access to an ammunition dump. After dressing up as firemen they are called to a real fire.

When the light is left on in the church hall, Chief Warden Hodges suspects that Mainwaring is the culprit and takes him to court. The verger knows what happened, but Hodges will not let him tell the truth.

The platoon is asked to provide guard duty at a testing ground for secret weapons, but when one of the devices gets out of control the platoon has to give chase.

A German pilot has bailed out and is caught hanging by his parachute on the clock tower. The platoon climbs up to rescue him but after Jones breaks the ladder, it's the platoon that needs rescuing.