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...

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.

Capt. Mainwaring decides to harden the platoon's feet by long route marches. When the platoon has had enough the men find a clever way of stopping him.

The platoon has moved to a new HQ's position on the beach. When Pike fails to turn up they find him caught up in the barbed wire at the waters edge. With the tide coming in, Mainwaring and Wilson mount a rescue mission, but someone else gets there first.

In Capt. Mainwaring's absence Wilson organises a darts match against the ARP in the local pub. When Mainwaring returns unexpectedly they have trouble getting the men back on parade.

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.

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?

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.

Sgt. Wilson becomes a manager of his own branch and gets a commission on the same day. But hours later his new branch is destroyed during an air raid. Mainwaring offers him his old job back and his former rank.

When the ARP Headquarters has been destroyed, Hodges and the wardens move into Mainwaring's office and the two of them start arguing over space. Later the chimney catches fire and they have to work together to put the fire out.

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.