Local bank manager Mr Mainwaring decides to form a Local Defence Volunteers force appointing himself as commander. He sets about recruiting members and organizes their first training session.
Captain Mainwaring realises his troops are poorly armed. To cut through the red tape and speed up the arming process he decides to liberate weapons from the local museum of Historic Army Weapons.
A new volunteer applies to join the troop who outranks Captain Mainwaring and insists that the Captain hands over command to him. He also promises that he can arm the troops with rifles. Captain Mainwaring has to decide whether to hand over his command or not.
Captain Mainwaring briefs the troops to be on the lookout enemy agents. They take two German airmen prisoner whose aircraft was shot down during an airaid and find out that there is a reward for their capture.
The platoon is inspected by a Major from JHQ who thinks that Lance Corporal Jones is too old. To justify his place in the Home Guard he must complete the assault course in under 15 minutes.
The Walmington-on-Sea Home Guard are asked to supply a guard of honour for a visit by the Prime Minister but a Major from JHQ wants them to prove their merit on the rifle range first.
A training exercise pits the platoon against a regular army unit as they find out what the Highland Regiment keep under their kilts...
As the church bells sound, the platoon naturally think the invasion has begun and hasten to the gun post at Godfrey's house...
Mrs Pike has told Frank that a little Arthur is on the way. Mainwaring insists that Wildon does the decent thing. "You can't go about behaving like Errol Flynn you know."
Corporal James forgets where he has put the money.
Puffed-up Captain Mainwaring and his pensionable platoon are ordered to clear the area for a major Army exercise - but come across a problem in the shape of a steam engine blocking the path.
The elderly platoon take part in an exercise with the regular Army and everything goes swimmingly - until pompous Captain Mainwaring casts himself as an enemy agent on the run.
The platoon tries to dish a German air crew out of a dinghy on a lake.
The vicar holds a Comforts for the Troops Fund bazaar where Mainwaring finds himself bidding against Pike for a highly prized orange. The pipsqueak reveals a stubborn streak that costs the thick-skinned captain an arm and a leg.