Main plot: Bruce Grove is looking for his lost dog, which has been captured by Roy Aloak and his brother Ken. Bruce is joined in the search by his father Theo, who brings in some musicians. They spot Roy and Ken and give chase. Roy and Ken jump into a cab and head for Marylebone. Bruce and Theo are offered rail tickets to London Bridge by a pair of strangers who turn out to be Parson Sal Green and her boyfriend Fred Monton. They can't get across the river because the bridge is closed, but luckily Don turns up, who is now calling himself James Hartlan. He offers to get them to Marylebone, but at a price. They get on the next train to Banbury.
When they reach Banbury, they head for the home of Canon Bury, a priest who assists them with the plan. They run into Charles Denton, who turns out to be the mastermind, and the five of them manage to subdue Roy and Ken and tie them up in a barn. They contact DI Warren Street, and Roy and Ken are sentenced to prison, where Roy is reunited with his former associates Wes Tacton, Colin Dale and Stan More. Bruce and Theo return to join Sal and Fred, who agree to get married. Don arranges the wedding, with the reception organised by Ken Sington.
Sub-plot: The delivery men Tony and Dudley deliver a parcel to a Mr Walt Hamstow, and then have to get across to South Kensington to deliver a vacuum cleaner to a Mr George West at 7 Leyburn Avenue. Their satnav breaks down and they can't find the street, so they phone Mr Hamstow for directions. His wife directs them there, but when they arrive they can't see any numbers on the doors. They try a buzzer marked "[[Thomas Enham|T.T. Enham]" and are confronted by his son Syd Enham, who tries to invite them to a bizarre 'romp' where rats are eaten for dinner. They rush out and then realize they've left Mr West's vacuum cleaner behind.
They go into a local pub, where Tony suggests they get another vacuum cleaner sent over from the depot. Dudley says that there's no time and that the head of operations wouldn't let the staff go. Instead he buys a cheap model from a friend of his who runs a nearby electrical shop. They return to Leyburn Avenue and try to deliver the cheap cleaner, but Mr West doesn't want it. Dudley explains that the Enhams must have received Mr West's cleaner and suggests that he swaps them over. Mr West refuses to go and calls them "vandals", but Dudley and Tony rush off to another delivery.