London, 1960 The lives of teenage twins Maisy and Duncan change forever the night their sick mother is taken to an asylum. Sent to live in the New Forest with their cold-hearted grandmother, Mrs Mitcham, they feel unloved and abandoned. And when one day Duncan doesn't come home from exploring in the forest, no one - least of all grandmother - appears to care about his disappearance. The police, who've found the bodies of other missing boys, offer little hope of finding Duncan alive. Yet Maisy refuses to give up. Though she doesn't know the woods well, she knows someone who does. The strange old woman who lives at their heart. Dare Maisy enlist the help of the woman in the woods?