The plan is to requisition any firearms from the local museum of Historic Army Weapons – but to do so, the platoon must first find a way to outwit the 88-year-old caretaker, who happens to be Lance Corporal Jones's father.
They receive a letter from the Peabody Museum of Historical Army Weapons, informing them that they will have to close their account for the duration because the curator has joined the navy.
Wilson is not so sure, but Mainwaring organises "Operation Gun Grab", and tells Miss King to write a letter to give to the caretaker in charge.
True to form, the cantankerous old man refuses to let the platoon in, so they decide to try force, using scaling ladders and battering rams, but to no avail.
The platoon prepares to leave defeated, until Jones and Walker find a Chinese rocket gun, and wheel it back to the church hall.