The BAU team travels to Houston to investigate a series of seemingly random murders at construction sites. At first, Hotch, Gideon and the team believe they are dealing with a homeless vagrant who is terrorizing a Houston neighborhood slated for revitalization. But after viewing satellite photos of the crime scenes, the BAU team realizes that the UnSub left an SOS distress signal at one of the murder locations and they begin looking for a man with a military background. Meanwhile, the team notices a distinct change in Reid's demeanor.

Source: CBS