Reid receives notification via anonymous email of the hidden whereabouts of Owen Quinn, an FBI agent with the Violent Crimes Apprehension Program (ViCAP) until he quit one year ago. He aspired to be part of the BAU, but broke protocol in a potential case, leading to him quitting to pursue the case on his own in his obsession on the issue. That case, the unsub who he coined the Strangler, had one known victim, although he believed there were others, he fitting missing persons into his victimology to support his theory, most of those missing persons who ended up being found and not potential victims of this supposed unsub. The many questions of the BAU, the answers to which would will help them solve the mystery of Quinn's situation, include: who the anonymous email sender is; what the email sender's motive is; and why the email sender chose Reid, who barely knows Quinn. Through questioning Quinn, Quinn's family (the case which led to the breakup of his marriage), and his ViCAP colleagues, the BAU has to decipher if Quinn is telling the truth about what has happened to him over the past year or if it is just a story in hiding that he is the Strangler himself. That story is that he was held captive by who would seem to the outside world as a model suburban family, the parents, purportedly the Stranglers, who tortured him, while their late teenaged son, Theo, the only one in the household who showed him any sympathy.
—Huggo