A secretive vigilante group called Edge cleanses Galway of its worst criminals. But when someone starts picking off Edge members, private detective Jack Taylor steps in to investigate.

Edge, a shadow organization made up of the most powerful figures in Galway society, exists to rid the city of criminals and abusers who have evaded the law. Long wary of the organization, the Vatican is not pleased when rumors start swirling that one of the Catholic Church's own priests has joined its ranks. And who better to ask to intercede than the whiskey-swigging ex-cop who always seems to have one foot in the pub and another among Ireland's clergy?

Lately, Jack has been spending his days sitting at the bedside of a man he put into a coma and taking care of a little dog named Trip, bequeathed to him by a dead nun. Then an envoy to the Archdiocese shows up at his door, asking Jack to go speak to a priest named Kevin Whelan and dissuade him from any involvement with Edge. Jack accepts the mission, but the next day Father Whelan is found dead, hanging from a rope in his own backyard.

Would Edge really kill one of their own? And if not, who else would be bold enough to take on the most powerful organization in the city? As more Edge members are murdered, the Vatican grows alarmed that someone even worse will take their place. It's up to Jack Taylor to nail the culprit before Edge is dissolved completely and Galway is thrown into chaos.