Jones marries Mrs Fox but the service is interrupted when an invasion warning is sounded.

The platoon is given the job of guarding telephone lines. Mainwaring spots an unexploded bomb caught in the wires.

Frazer, distrustful of banks, keeps his savings in the form of gold sovereigns, but Mainwaring believes his hoard would be better in the bank. Rumours spread about the savings and when Frazer is seen carrying a box to the graveyard, the platoon follows.

As part of a Wings for Victory campaign, the platoon decides to stage a reenactment of the battle between Saint George and the Dragon. The ARP wardens, though, have been planning the same thing.

Pike borrows Mainwaring's recently acquired staff car to drive his new girlfriend to Eastgate, but it runs out of petrol on the way home, forcing Pike to spend all night pushing it back.

As the threat of invasion lessens, the towns people become lax. Mainwaring orders Operation Wake-Up, dressing up the platoon members as fifth columnists and telling them to act suspiciously. Eventually, the Eastgate platoon is called in to deal with them.