When former banana-grower Edris Tidson hears of a possible sighting of a water-naiad he insists that his wife, her aunt Prissie and Prissie’s young ward Connie, travel with him to Winchester in search of the nymph. As tensions rise between Connie and Edris, Prissie invites part-time Freudian Mrs Bradley to join them and unofficially observe Edris and his growing obsession. Then two young boys are found drowned and speculation mounts that the naiad is luring them to their deaths. Can Mrs Bradley unravel the mysteries hidden within the river?

The great detectives of fiction are men of varied and brilliant gifts—Chief Inspector Alleyn, Lord Peter Wimsey, Hercule Poirot, Albert Campion and their peers—but in this glittering company Gladys Mitchell’s famous Mrs. Bradley, ‘the greatest of women detectives’ as she has been called, is well able to hold her own. ‘Mrs. Bradley is a lovely ancient dame,’ wrote John O’London’s Weekly, reviewing one of her recent cases, ‘bouncing happily through crime with a will and a wit as deadly as a snake’s tongue.’