As soon as Kerstin Kvist arrives at remote, ivy-covered Lydstep Old Hall in Essex, she feels like a character in a gothic novel. A young nurse fresh out of school, Kerstin has been hired for a position with the Cosway family, residents of the Hall for generations. She is soon introduced to her "charge" John Cosway, a thirty-nine-year-old man whose strange behavior is vaguely explained by his mother and sisters as part of the madness that runs in the family.