It's 1852 and Margaret Lennox, a young widow, attempts to escape the shadows of her past by taking a position as governess to an only child at an isolated country house.
Cut off from the village, Margaret soon starts to feel that something isn't quite right. There are strange figures in the dark, tensions between servants and an abandoned east wing. Even stranger are the repeated trips away on business by Mrs Eversham, the child's mother.
Lonely, and unsure who to trust, Margaret soon finds distraction in a forbidden relationship with the gardener, Paul. But as Margaret's history threatens to catch up with her, it isn't long before she learns the frightening truth behind the secrets of Hartwood Hall.