The crocodile bird - Ruth Rendell

Liza is not your average teenager. Sixteen years old, she lives with her mother, Eve, in a secluded gatehouse, which she has never been allowed to leave. There was only enough room for two in their cocoon; intruders entered at their peril, only to mysteriously disappear...

Liza is not the only one to discover the truth behind her mother's pathological violence, or the dead bodies. When the police arrive on their doorstep, Eve throws her daughter into the real world, to protect her from the consequences of her own chilling crimes.

As Liza runs into the arms of her secret lover, she begins to see the logic behind her mother's gruesomes crimes, and must accept the possibility that she has inherited Eve's lust for murder...