: A former journalist who lost his sanity after the death of his son. He became obsessed with the idea that a government conspiracy or an environmental factor caused his "infestation."

The Behavioral Analysis Unit (BAU) travels to , to investigate a series of murders involving victims whose bodies are covered in scratches. The investigation reveals that the UnSub (Unknown Subject) suffers from Morgellons disease , a delusional skin infestation where the sufferer believes their skin is infested with bugs or fibers. The UnSub: Leo Jenkins

: He kidnaps individuals he believes are part of the "cover-up" or who can help him expose the "truth." He uses a high-frequency device to stimulate the sensation of "crawling" in his victims to make them understand his pain.

: A significant subplot involves Aaron Hotch profiling a woman named Lisa who also claims to have the condition. Unlike the aggressive UnSub, Hotch realizes her "itch" is a physical manifestation of grief and helplessness regarding her infant's death years prior. Episode Conclusion

: Jenkins targets members of a Morgellons support group, believing they are being silenced.