1859. Somerset, England. When widow Hester Travis decides to sign over all her family's worldly goods - and their freedom - to a secretive religious community, her daughters, headstrong Ruby and fragile Irene, have little say in the matter. Led by the charismatic Reverend Prince, the women enter a world with its own set of rules and where Irene, cursed with seizures and ill health, is believed to have second sight. But as Hester and Irene are drawn into the community's twisted philosophy, Ruby detects a darker truth stalking its shadowy corners. When a shocking discovery throws the community open to scrutiny, the stakes are raised and Ruby realises that it is not only their souls that must be saved ...