She thought I was her best friend - she had no idea how wrong she was... Isabel is the daughter of the local landowner and lives in the big house; a beauty who basks in love and security and exudes sweetness. Her friend Diane is the daughter of a tenant farmer living in a broken down cottage. With a distinct lack of life's advantages and bitter memories of childhood, she is not beautiful; she is clever, vengeful and consumed with envy. Their friendship very quickly becomes intense and Diane is invited to live in the big house. Very soon, her girlish charm turns to seduction, teenage friendship becomes manipulation - but do Isabel and her family realize that they have a destructive cuckoo in the nest?