Kerstin Kvist, a young nurse fresh out of school has been hired for a position with the Cosway family, residents of the Old Hall in Essex 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. Bitter wrangling among Julia Cosway and her four grown daughters becomes increasingly evident. But this is just the most obvious of the tensions that charge the old remote estate, with its sealed rooms full of mystery. Soon Kerstin will find herself in possession of knowledge she will wish she'd never attained, secrets that will propel the occupants of Lydstep Old Hall headlong into sexual obsession, betrayal, and, finally, murder.