It is the sweltering summer of 1997, and Karen is a strait-laced, straight-A university student. When she meets the impossibly glamorous Biba, a bohemian orphan who lives in a crumbling mansion in Highgate with her enigmatic brother Rex, she is soon drawn into their world. As the summer progresses, Karen becomes tangled up in their tragic family history and the idyll turns into a nightmare, culminating in murder.