When two human skeletons are found in the backyard of an African American family, the BAU heads to Virginia to investigate. The medical examiner determines the victims were women whose genitalia were mutilated before being killed ten years ago. The volatile behavior of the Johnsons' son Lyle makes him the BAU's prime suspect, and their theory is supported when one of the victims is identified as Mary Ann Beck, Lyle's former high school classmate. When they find pictures of Lyle with the victim, he breaks down and admits to killing both victims, but the team suspects it was a false confession after a third skeleton belonging to a man killed 35 years ago is found under the Johnsons' shed.Shortly after, another skeleton found in the backyard is identified as a friend of Mary Ann's father Karl, and both men belonged to a Klan chapter in the sixties. The team discovers the second female victim is the daughter of another member of the same chapter and that Karl had a half-sister, Audrey, who also attended the same school as Charles and the Klansmen. JJ locates an apology letter Audrey wrote to Charles on her deathbed and they confront Charles with the note. He reveals that Audrey lied about being raped by him and the Klansmen castrated him in retaliation. Charles mutilated and murdered his tormenters, and Audrey's letter triggered him to do the same to the daughters of the Klansmen who died before he could kill them. Rossi agrees to keep Charles' secret that Lyle is not his biological son in exchange for his full confession.