SEASON 9, EPISODE 910 - Following a series of apparent prank calls from a young child to Malcolm and Lida Taffert, the couple’s son Andy is kidnapped soon after. Reid connects the kidnapping to a cold case in which a young boy, Frankie, was abducted and killed following a string of similar calls. When the voice from the cold case matches the voice from the calls the Tafferts received, the BAU determines they are dealing with the same UnSub who is using a recording. They soon find Andy dead in the woods, having been killed mere hours after his abduction. A faint voice of a woman speaking Portuguese on the recording leads them to speculate the involvement of foreign prostitutes and they track down a woman who admits she was paid to engage in acts of S&M with an American man and his Eastern European wife. The UnSub’s pattern diverges when he abducts Lida, and the team realizes the link between she and Frankie’s mother Nadia is their Eastern European heritage. As Nadia had committed suicide, the team searches for other Eastern European women who committed suicide and zero in on a woman who tried to kill her son Daniel along with her, but he survived. They determine Daniel took on a false identity as Andy’s teacher and lured him away. Daniel’s psychiatric records reveal that he was forced to record his father making his mother perform demeaning sex acts with prostitutes. Daniel saw the victims’ parents as surrogates for his own and killed the children as his way to save them. The BAU is able to track Daniel down and save Lida before she is killed.