SPOILER ALERT
The depth of despair to which Det Superintendent Lorimer falls in the aftermath of a shooting is a focal point and a study in the price that our police pay in the line of duty. Lorimer faces a father, a drug dealer, who is furious, and has just killed his wife and two sons. He is now holding his daughter hostage and kills her and himself in front of Lorimer, leaving the Detective with the cries of the little girl in his mind. He is unable to go on facing a serious depression, and failure to thrive. He is sent to Castlebrae, in Acuhterarder in Perthshire for recovery. Every month a tiny piece of salary is deferred to support the Police Treatment Center. Lorimer believes that it is really for those physically injured in the line of duty. Once there he begins to recognize the fundamental healing that they accomplish in the mental and physical work that each patient works on. He eventually returns to work a better man. While there, watching the news one evening he sees the man who had escaped the police net in the last case, Quiet Release, in which elderly, dying and homeless were dispatched with injections by various people. Many went to jail, one escaped.
Once back at work Lorimer is put in charge of the Major Incident Team and the case to find this man, by the Deputy Chief Constable Caroline Flint. The killer goes my many names and it is the first line of approach to find out who he is now. From Gordon Smith to Charles Graham to Richard Aitken he assumes new identities as necessary to keep out the hand of the police. He was born Oliver Nimmo, killed his parents and after dropping out of medical school, went on his spree of killing those he deemed needed to die because they were a drag on society. But he also got high from the act, and he got rich from the service. He lives a lavish life style in a penthouse apartment, with beautiful clothes, while assuming the position of a doctor, social worker, orderly or nurse to gain access to the people he wants to kill. He approaches Jack Gallagher, the drug boss in the city for the drugs.
At the same time it comes to the attention of several police officers that a colleague Detective Superintendent Mark Mitchison is dirty. DCI Niall Cameron asks a friend Paul Doherty, an It wiszard and hacker to get into the account of Mitchison to see if there is a connection to Jack Gallagher. Once found he is on Lorimer radar for later handing off to Standards, and for watching as they pursue the killer. With his team Lorimer tracks the killer, captures him, and at the same time confronts Jack Gallagher attempting to kill Mitchison.
The tackling of the issue of the mental health of police officers as they face horrific cases and the violence was brilliantly done, and made this installment particularly good. Also the methodical pace to identify and locate the killer was perfect.