The BAU is assigned to work on an old case, which was Hotch's first as lead investigator for the BAU, namely that of the Boston Reaper. The case was originally closed ten years ago by Tom Shaunessy, the lead Boston police detective working on the case. When the case officially closed, the killings stopped. With Shaunessy now on his deathbed, he discloses to Hotch the reasons for closing the case. After Shaunessy's death, the killings once again begin. Hotch is taking this case personally as, although he had thought and worked on his own on the case in the intervening years, he feels he could have stopped the Reaper during this time which may have prevented these recent deaths. Beyond the random persons chosen as the murder victims, the one person who may be in danger as a target of the Reaper is George Foyet, the only known person who survived the Reaper's murder attempt ten years earlier. One other person who may provide a symbiotic benefit to the BAU in finding the Reaper this time is Ray Colson, a reporter who wrote an official biography on the Reaper.