JJ meets a friend while out jogging, who later turns out to be the BAU's new Section Chief, Mateo Cruz. After introducing himself to the BAU, Cruz tags along with the team as they go out to investigate the case of a man who was lobotomized.  After discovering an ocular-nano implant in the victim's eye, the BAU realizes that the Unsub was watching them.  Eventually the team figures out that there are two victims: the one they found, and his sister, and that their brother is the Unsub who is acting out aggression against his family for his perceived rejection of them. After the Unsub implants an ocular-nano camera into his sister's eye and then lobotomizes her,  Hotch and Cruz track him down.  They discover at the same time that he had also put an ocular nano implant into his own eye, with the intention of beaming the video to the internet.  Hotch convinces him that Garcia had shut down the transmission.  They take him into custody.  Meanwhile, JJ is pretending to the team that she doesn't know Cruz.  Cruz and JJ agree to keep their secret, because of a case that's been open for three years.