In order to recuperate from her last escapade and re-grow some hair, Agatha Raisin goes on holiday to the seaside town of Wyckhadden. However, the holiday is not what Agatha hoped for. The weather is crummy, all five of her fellow hotel guests are elderly, and time hangs heavy. A chance discussion with a fellow guest leads her to the door of Francie Juddle, a local woman who claims to have the power of witchcraft. Agatha is not impressed with Francie, but does buy a hair potion and a love potion.

That same night, Agatha sets out to visit Francie and accuse her of fraud. Agatha walks into the cottage unannounced and discovers a very dead witch. The police, in the form of handsome officer Jimmy Jessop, bring her in for questioning and request that she stay in town.

Agatha does so because it is apparent to her that one of the hotel guests must be the killer. Her use of the love potion on Jimmy Jessop yields surprising results. When another murder occurs and Agatha finds herself the center not of danger but of amour, she realizes that there may just be a future for her in Wyckhadden.