For Nan, on the threshold of puberty, and her younger sister Mary, innocence blends uneasily with the trials of convent life and a shadowy knowledge of the facts of life. For their mother, buffeted by the whims of her tyrannical, unreliable husband, the days take on an unreal, dreamlike quality. And while Nellie, the Dickensian maid with a dubious past, regales the children with tales of her antics, home becomes a haven to a stream of unwelcome guests - as the dangerous depths of the adult world loom ever closer...