In Vengeance, amateur detectives, Ruth, her husband, Ted, and their neighbors, retired CIA operatives, Lil and David are back to solve another murder. Their neighbor's nineteen-year-old granddaughter, Katie, a troubled young woman with a recurring drug habit, is dead. The police conclude that Katie died of an accidental drug overdose. Katie's grandmother, Connie, is convinced her granddaughter has been murdered. She enlists the help of her four neighbors who begin to look for likely suspects. Whittling down the list of suspects is a challenge since Katie fantasized that dozens of casual acquaintances were in love with her. Had one of her fantasy romances gone very wrong? Our intrepid team is put to the test after a second murder occurs. Leads take them from Delaware, to Arizona, to Virginia in pursuit of the killer.