It is the summer of 1851 and Charlotte Morrison is on holiday in Germany with her brother and his wife. On the surface, Charlotte is an unmarried aunt with a sparse, unfulfilled life. But beneath that quiet respectability lie unsuspected depths hidden murmurings.

On a day trip boating down the Rhine, Charlotte sights a fellow traveller, Edward Newman, who releases the hissing floodwaters of her subconscious. Dark and dangerous, they sweep Charlotte towards the watershed of her life, stretching her imagination to its limit; almost to breaking point.

Shortlisted for the Booker Prize in 1981, Ann Schlees evocative, heady novel creates an aura of tension that is as compelling as it is mysterious, forcing her characters to confront each other as well as themselves over one hot summer abroad.