No-nonsense P.R. whizz Agatha Raisin leaves the London rat race to live in the Cotswolds village of Carsely, where local bobby Bill Wong suggests she involves herself in local activities. So she enters the quiche-baking contest at the village fete - and cheats by buying her offering at a London bakery, a secret she shares with Gemma, the cleaning lady she has filched from snooty Sheila from next door. Nonetheless the judge, philandering Andy Cummings-Browne, awards the prize to Ella Cartwright, one of several married women with whom he is cheating on his wife Jo. Next day Andy is found dead after eating Agatha's quiche. Agatha's friend Roy convinces her that, if she wants to make herself truly popular, she must find out who used her as a scapegoat in order to kill Andy and so, using her P.R. methods, she turns detective. Any of the dead man's mistresses could be the murderer, even Jo or barking mad Maria Borrow, who claims he was going to marry her. Agatha eventually exposes the murderer and proves Roy right when all of a sudden everybody is very nice to her.