The platoon finally gets to grips with the enemy when it has to guard some Nazi submariners. But the Germans turn the tables on Mainwaring and try to escape, resulting in Jones ending up with a grenade down his trousers.

Godfrey asks to leave the platoon because he doesn't want to fight. Mainwaring is furious and the rest of the platoon shuns him until they find out that he was a hero from The Great War. So he rejoins the platoon as a medical orderly.

The platoon is assigned guard duty on an isolated, disused pier for a week. However, thanks to Pike's poor judgement over how to moor the boat, they end up stranded with no contact with the mainland and no food. Attempts at Morse code only prompt Hodges to pursue the platoon to get them to 'Put that light out!' and he ends up stranded himself. If that wasn't enough, Jones spots a stray mine under the pier, but does Hodges have a solution that'll 'bowl them over'?

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.

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 rapidly filling with water. But does Godfrey have a solution that is more useful than asking to be relieved?

The bank takes a direct hit during an air-raid, but the bomb fails to explode, leaving Mainwaring and Wilson stuck in the vault with it. When the bomb disposal officer leaves to collect the right tools, the platoon members take matters into their own hands.

The platoon captures a runaway barrage balloon and while trying to secure it, Capt. Mainwaring is carried aloft.

Capt. Mainwaring has the idea of small armed patrols to wreak havoc upon the enemy using a small re-processed boat the bank has acquired. After a practice on the river they get lost in the fog, and thinking they have drifted across the channel and are about to be captured by the Germans, they are in for a shock when they find out where they really are.

When the church bells start to ring, the platoon leaps into action. Jones takes half the platoon to Godfrey's cottage to set up a machine gun post while Wilson, not knowing where Jones has gone, also heads for the cottage where they both mistake each other for the enemy and prepare to attack.

The platoon guards some Italian POW then suspicion falls on Walker that he may be helping them to escape. Mainwaring then sets a trap with a surprising outcome.

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.

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.

Capt. Mainwaring promotes Frazer to Lance Corporal, thus causing friction between him and Jones. When Frazer starts getting above himself, Mainwaring cancels the promotion.

When a low-flying German aircraft attacks Warmington-on-Sea, the platoon, under the command of LCpl Jones, fires at the aircraft and uses up all its ammunition. Mainwaring is furious and orders an investigation.

Capt. Mainwaring is found not to have held the King's Commission so he is reduced to the ranks and Sgt. Wilson takes over command of the platoon. After a disastrous war game against the Eastgate Platoon, his men ask the Colonel for him to be reinstated.

The search begins for a spring clip for a Lewis gun that Frazer has lost whilst cleaning it. The trail leads them through Frazer's workshop to a Funeral Director, to Mr. Bluett's dining room table, to a graveyard. The platoon stops at nothing, committing various crimes including house breaking and grave robbing to get the clip back. But will they find it in time to save Frazer from a court martial?

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.

The platoon has gone to a camp to undergo an efficiency test. Meanwhile Walker has a van load of onions he's sold to Hodges, who isn't letting them out of his sight, thus he has pursued the platoon to the camp. Later, with no blank shells to use on the test, Mainwaring has a brainwave regarding what to use as ammunition!

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.

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.

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 classified news is shared that the King is to travel through Warmington-on-Sea by train, Capt. Mainwaring and the platoon are detailed to form a guard of honour. Then, when another train breaks down on the main line, blocking the King's route, the platoon swings into action.

Walker is finally called up but Mainwaring tries to get his call-up deferred because of his value to the platoon, but he is still conscripted, only to find out that he is allergic to the army's corned beef.

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?