DS Catrin Price is on administrative duty recovering from the trauma of her last case, when she receives a series of cryptic messages from an old school friend. She tracks him down to an isolated town in the wilds of the Brecon Beacons. There she finds him destroyed by fear for his missing daughter and living in terror of a shadowy figure he refuses to name.
The girl is a promising singer, and all Cat has to go on is a haunting video of her performing in a local talent competition. Other girls in the area have been going missing, and when one of them is found dead in an abandoned mine shaft, Cat fears the worst.
She embarks on a journey that leads to one of London's most notorious drug gangs and into the darkest corners of her mind. Cat will stop at nothing to uncover the truth, but there are people who will do anything to keep it hidden - and they are watching her every move.