Compton Castle is an old Victorian psychiatric hospital, long since scheduled for demolition, but reprieved by financial cutbacks. Its warren of endless corridors, tiny rooms, huge wards, and acres of grounds were designed as a sanctuary for the mentally ill. But it now proves ideal for another purpose - the concealment of murder. Physically and mentally battered after his latest case, Sergeant Trevor Joseph is at Compton Castle as a temporary patient, but therapeutic tranquility soon gives way to horror when a corpse is dug out of a flowerbed. Police investigations then disclose two more victims: both female, both young, and both linked to the hospital. Whether staff or patient, everyone within the moldering walls is now in danger so long as a serial killer stalks the corridors. As Joseph interrogates personnel and examines files, a complexity of suspects emerges ... while an ingenious murderer watches and waits to strike again.