In elderly priest is nearly beaten to death. A special-needs boy is brutally attacked. Evil has many guises, and private investigator Jack Taylor has encountered most of them. But nothing before has ever truly terrified him until he confronts a group calling itself Headstone, responsible for a series of random violent crimes in Galway, Ireland. As Headstone barrels along its deadly path right to the center of Taylor's life, he will need to call upon his own capacity for brutality in order to stop them.