Helena Lanark is an elderly woman, living in a luxurious care home. The heiress of an immense family fortune, she keeps the secret to the horror which once occurred within the Lanark family house. Jane Tennison is leading a murder investigation into the recent brutal death of a young girl, her decomposed starved body discovered in an old air raid shelter in the garden of the Lanark's now derelict house. Initially the focus is on identifying the victim, until another body is found, hidden in the walls of the shelter. As the investigation and search for answers intensifies, Jane travels to Australia. There she discovers the dark secret, that the Lanark family has kept hidden for decades. A secret, that not only threatens to bring down a family dynasty, but also places Jane Tennison in mortal danger.