Every July, the lucky owners of Cornish holiday homes set off for their annual break. Loading their estate cars with dogs, cats, casefuls of wine, difficult adolescents and rebellious toddlers, they close up their desirable semis in smartish London suburbs - having turned off the Aga and turned on the burglar alarm - and look forward to a carefree, restful, somehow more fulfilling summer.
Clare is, this year, more than usually ready for her holiday. Her teenage daughter, Miranda, has been behaving strangely; her husband, Jack, is harbouring unsettling thoughts of a change in lifestyle; her small children are being particularly tiresome; and she herself is contemplating a bit of extra-marital adventure, possibly with Eliot, the successful - although undeniably heavy-drinking and overweight - author in the adjoining holiday property. Meanwhile Andrew, the only son of elderly parents, is determined that this will be the summer when he will seduce Jessica, Eliot's nubile daughter. But Jessica spends her time in girl-talk with Miranda, while Milo, her handsome brother with whom Andrew longs to be friends, seems more interested in going sailing with the young blond son of the club commodore.
Unexpected disasters occur, revelations are made and, as the summer ends, real life will never be quite the same again.