West Yorkshire, 1904. When newly graduated nurse Ruby May takes a position looking after the children of Charles and Lilian England, a wealthy couple from a powerful dynasty of mill owners, she hopes it will be the fresh start she needs. But as she adapts to life at the isolated Hardcastle House, it becomes clear there's something not quite right about the beautiful, mysterious Mrs England.

Ostracised by the other servants and feeling increasingly uneasy, soon a series of strange events will force Ruby to question everything she thought she knew...