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.

LCpl. Jones wants to marry Mrs. Fox but has to get Capt. Mainwaring's permission. During the reception an invasion alert is called and Jones spends his wedding night on the beach doing guard duty. Note: as the end of the series, it aired on Remembrance Sunday and ended with a tribute from the platoon to the real Home Guard.

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?

Capt. Mainwaring decides to enlist women to the platoon to assist with the war effort. After initial interviews go rather less than satisfactory, a Mrs. Fiona Grey walks into his office and into his life. Mainwaring is flattered that Fiona not only has similar views to him about the war, but also is complementary about his persona. He finds himself falling in love. Unfortunately the men very quickly realise and start to gossip behind his back and Fiona decides to leave, but can Mainwaring get to the station in time to stop her?

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 is still ordered to do so. When the filming is cancelled, Mainwaring and the men, still dressed as German soldiers, are spotted in the local pub and the alarm is raised.

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.

While the platoon is at a training camp, Mainwaring gets drunk with the other officers during the night and misses the live grenade training the following morning. Later during the training one of the grenades lands in Jones's van and Mainwaring rides to the rescue.

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.

During home guard manoeuvres LCpl Jones, disguised as a log and helped by Frazer in a diving suit, floats down the river in order to attack the Eastgate platoon's headquarters.

The platoon is manning the local lighthouse and accidentally switches on the light and can't find a way to switch it off. During an air raid they must find a way to cover up the glare.

LCpl. Jones goes to a reunion of his old regiment. While he is away an old comrade who fought in the same battle joins the platoon and accuses Jones of cowardice. Upon his return Jones has to tell the real story.

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.

At the bank the door to Mainwaring's office is replaced with a paper door. Adding insult to injury 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. 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, blackmails him to get the airfield moved 200 yards.

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 butterfly spring 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 spring back. But will they find it in time to save Frazer from a court martial?

Mainwaring watches a film reel at the cinema which shows Winston Churchill inspecting Army troops and their mascot - a ram, of course where Mainwaring's concerned. If another platoon has a mascot, so must his. Sponge volunteers one from his farm but they have to catch it first; something that of course ends in complete disaster with Pike up to his neck in it - literally. Meanwhile the town parade is being organised and of course Mainwaring wants the platoon to lead, but Hodges has other ideas...

In a cricket match between the platoon and the ARP wardens, Chief Warden Hodges has a secret weapon up his sleeve: he plans to recruit Ernie Egan (played by England's fast bowler Fred Trueman), a professional cricketer. But all does not go as planned.