Isabel Burley returns to her childhood home to look after her mother, Serena, who is suffering from Alzheimer's disease. There she finds a bemused, angry, charming old woman, prey to the threats of failing memory, the inability to run her own home - and the local villains who are eyeing her isolated house. As the villains inexorably move in, Isabel finds herself struggling with another threat from within. She thinks she has gone home to do some good, but is she really looking for the love she lacked as a child? Alienated by her mother's growing eccentricity, the two women become locked in a relationship of love, hatred and simmering violence, with roots that go deep into the past.