Texas cop Phil Davis investigates the victim of a road accident who bears scars inflicted over decades. Discovering that similarly scarred men have recently died, Phil digs deeper. Seeking to unearth a dangerous undercover group of political extremists, FBI agent Luis Valdez makes a connection to the scarred men and the long-ago death of a young woman. While Phil and Luis tie together the two investigations, psychiatrist Rozalina Ericson pursues her own agenda through an old man who has served 25 years for the young woman's death. And then there is Quinn, ruthless, unstoppable, an all-purpose killing machine wreaking havoc in northern Texas and New Mexico. These lives intertwine explosively as today's upholders of law and order clash with centuries-old religious extremism.