A young woman living alone is found dead in her home when the police do a routine welfare check. Detectives O'Toole and Starker barely begin investigating when an older couple is found bound and murdered. Are the murders related? With little to go on, they appeal to other agencies and learn that similar crimes are being committed further up the coast. What do all these victims have in common? As clues emerge reflecting a calculated murder scheme, the detectives fear the worst and seek help from multiple law enforcement agencies in more than one state.