Galway private investigator Jack Taylor confronts an evil coterie named Headstone, who have committed a series of random, insane, violent crimes in Galway, Ireland.

Seems impossible, but Jack Taylor is sober--off booze, pills, powder, and nearly off cigarettes, too. The main reason he's been able to keep clean: his dealer's in jail, which leaves Jack without a source. When that dealer calls him to Dublin and asks a favor in the soiled, sordid visiting room of Mountjoy Prison, Jack wants to tell him to take a flying leap. But he doesn't, can't, because the dealer's sister is dead, and the guards have called it...