It's 1852 and Margaret Lennox, a young widow, is offered a position as governess at Hartwood Hall. She quickly accepts, hoping this isolated country house will allow her to leave her past behind. Cut off from the village, Margaret soon starts to feel there's something odd about her new home, despite her growing fondness for her bright, affectionate pupil, Louis. There are strange figures in the dark, tensions between servants and an abandoned east wing. Even stranger is the local gossip surrounding Mrs Eversham, Louis's widowed mother, who is deeply distrusted in the village. Margaret finds distraction in a forbidden relationship with the gardener, Paul. But despite his efforts to reassure her, Margaret is certain that everyone here has something to hide. And as Margaret's own past threatens to catch up with her, she must learn to trust her instincts before it's too late.