Cousin Julie is getting married. However, trouble comes when "Executive bridesmaid" Karen asks her troubling questions about her previous boyfriends, and Ben asks the vicar complex theological questions involving the baby Jesus and lasers.

Karen mourns the death of a mouse killed by her parents while also getting into the habit of swearing, Ben uses some devious tactics when he stands for election as class rep and Jake causes Sue to worry when he brings home a girl for tea. Meanwhile, Pete and Sue have to worry about money, chest pains, a friend is using them as a glorified babysitting service and the the superior mother next door.

Sue and Pete ban TV as they attempt to have a traditonal family Sunday playing games like hide-and-seek, Pelmanism and scissors, paper, velociraptor, but matters are complicated when Grandad comes to stay after he suffers an accident involving a tin of baked beans. Later, Pete worries about teaching sex education, Karen plays the recorder, and Ben's headmaster suggests that he should take a few days off school.

Pete and Sue find themselves in every parent's ultimate nightmare - trapped in a foreign airport with three bored young children (and an increasingly bewildered Grandad). Six-year-old Karen grills her Dad about al-Qaeda, and security staff grill eight-year-old Ben about the worrying objects in his bag. How many hours will it take them all to run the gauntlet of delays, security checks and endless games of I-Spy? How many times will they lose Grandad? Will they end up in Guantanamo Bay? Will Ben find the Spanish for "Can I play with your machine gun?" and what idiot let the kids drink double espressos?

A Croatian babysitter has a night to remember when Mum and Dad manage to escape for a meal together. Meanwhile, Ben gets thrown out of his sister's pretend restaurant, and Jake gets advice from Grandad on why he should not invade Russia. And a big decision is looming about Grandad's future, but who is going to tell him?

Yet more chaos for the Brockman family as six-year-old Karen denounces Satan and Ben gets on the wrong side of a no-nonsense referee. Meanwhile, Dad is asked to 'sex up' an official document and Mum's competition with her impossibly perfect neighbour reaches a sticky conclusion. But most worrying of all, there is Grandad's fate to be decided.

The semi-improvised sitcom continues as a thunderstorm brings night-time chaos to the Brockman family. Ben wants to go out and dodge the lightning, while Karen is writing to the Prime Minister, asking him to fire her teacher. Jake is being manipulated by his girlfriend, the couple next door are hurling abuse at each other, and Mum has received some shocking news. None shall sleep. And morning brings a policeman to their door.