As a favor to Cruz whose friend, Peter Coleman, is the lead investigating sheriff, the BAU take on as their next case the murder of prostitutes in rural/small town Texas, the latest in Briscoe County. The latest victim is Abigail Jones, who was shot execution style in the back of the head, but not before she was tortured by having deep lacerations carved into her back in a cross-hatch fashion. This M.O. mirrors the murder of another prostitute, Hannah Kelly, in a neighboring county six months earlier, and the murder of a john, Lucas Wagner, eleven months earlier. The team quickly learns that Wagner, although convicted as a john, was truly a prostitute as well. They will also learn that forensic evidence will be difficult to come by due to the general protocols of various officials in the area. Their initial suspicion is that the murders were indeed torture, or consensual S&M sessions gone wrong, and that a john nicknamed "Mack the Knife" may be involved. With subsequent victims, they come to the understanding that the lacerations are not torture but religious symbolism. Morgan also notices that some people seem to have some pertinent information, but are afraid to talk for fear of reprisal. Although they don't know who the unsub is, they have a good idea that someone trying to insert himself into the investigation can lead them to the unsub.