A man is pushed out of a fourth-floor Glasgow tenement window. When the dead man is identified as notorious crime boss John Cunningham, there is no shortage of suspects. However, the investigation takes a new turn when a witness to the killing is also murdered.That witness was a seven-year-old girl.Now, DCI Patterson must not only bring a murderer to justice but do so quickly to stop all-out gang warfare breaking out and calm a city demanding justice. Yet, with tragedy striking his own life, catching the murderer, now dubbed The Glasgow Psycho, will prove to be DCI Patterson's toughest-ever task.Glasgow's had its fair share of psychos, but this one tops the lot.