Perfect silence

A girl's body is found dumped on the outskirts of Edinburgh with pieces of her skin carved into it. Later, when Inspector Luc Callanach discovers a ghostly figure next to the abandoned infant, he understands the principle of the twisted game: the killer takes doll material from the bodies of his victims. Plus, someone is carving the letter Z into the face of unconscious drug addicts. Is it the same perpetrator? Luc and his colleague Ava must track down the killer before he strikes again - can they do it, or is it too late?