A war of words breaks out on the Scottish island of Portacarrick after a boy's warts appear to be cured by the waters of the Pixie Falls, a local spring with legendary powers.

Miss Emily Pride is the lady laird of the island, while her rival Miss Elspeth Cost wants to turn Portnacarrick into a health centre to compete with Lourdes. Then someone tries to kill Miss Pride, bringing her old friend Alleyn to the island to investigate the murder attempt. He finds adultery and bitter sexual rivalry.

Alleyn has just finished a secondment to the British Army, so he is glad of the trip to Scotland - and also the help of Agatha Troy, who is becoming more willing to take an interest in his affairs.