Murder and drug-dealing are all in the day's work for DCI Charlie Anderson, but everything's on a different scale now that psychopath Billy McAteer is back on the streets of Glasgow. Simon Ramsay, a seemingly respectable businessman, receives a photograph attached to an e-mail threatening to expose embarrassing aspects of his private life if he doesn't come up with fifty thousand pounds. In a state of panic he contacts his mistress, Laura Harrison, telling her a blackmailer has managed to get his hands on a compromising photo of them in bed together. Terrified of the consequences if her fiercely jealous husband finds out about her affair - and in a moment of madness that turns her world upside down - Laura enlists the services of Billy McAteer to deal with the blackmailer. Black Mail is a complex intrigue of drugs, blackmail and murder - and, this being Glasgow, the undercurrent of religious intolerance is forever bubbling just beneath the surface.