When a man is found beaten to death in a local Manchester park, Detective Constable Sam Parker is one of the investigating officers. Sam swiftly identifies the victim, but what at first looks like an open and shut case quickly starts to unravel when he realises that the victim's fingerprints were found on a knife at another crime scene, a month earlier. Meanwhile, Sam's brother, Joe - a criminal defence lawyer in the city - comes face to face with a man whose very presence sends shockwaves through his life. Joe must confront the demons of his past as he struggles to come to terms with the darkness that this man represents.