A sadistic killer, targeting teenagers. A city on the brink of terror. DCI Rohan Roy, running out of time. When the teenagers of Sheffield get hooked on an app that encourages them to self harm, the consequences are deadly and vicious. A teenagers body is found in an abandoned warehouse, and Detective Chief Inspector Rohan Roy is called in to investigate. As Roy and his team sifts through the secrets, he finds disturbing links to other families, and organised crime.When another body appears, Roy knows this blood thirsty killer will not stop anytime soon...