When Silla is fourteen years old and Nori is four, life with their abusive father in London gets so bad that they have no choice but to escape to live with their Aunt Catherine. She lives in a large manor alone in the woods, and though their mother hinted that she might be crazy, life there seems perfect and safe. Silla worries that everything is not quite right when Cath tells a few scary stories about the woods, and life only gets worse when Cath retreats to the attic and refuses to come back down. Silla does her best to take care of the young, carefree Nori, but when they begin to run out of food and are still afraid to pass through the woods, this home too feels more like a prison.
By the time a young man comes through the trees, it has been years. Nori is growing up, Silla is struggling to find food in the dead earth and Cath is pacing, always pacing in the attic. Silla doesn't trust anyone -- not the world inside the manor or the trees outside. All the digging in the garden brings up is roots, and each time the trees seem a little closer, until Silla is sure they're watching. Are these things really happening? Is she going mad like her aunt? Is any of the manor safe anymore?