When prostitutes in Miami are discovered murdered in a similar style to local animals found dead there, the BAU must work fast to find an unsub whose confidence is quickly escalating. Also, Morgan tries to increase Reid's athletic skills by convincing him to join the bureau's softball team.

The Replicator zeroes in on the BAU when the killer targets one of the team as the next victim. Also, the BAU is called in to investigate a string of deaths in Manhattan tied to apparent ecstasy overdoses, and Hotch discovers that his estranged brother, Sean, is caught in the middle.

The BAU meets their new section chief, Mateo Cruz, who, unbeknownst to them, shares a long work history with JJ. Cruz joins the team as they comb the streets of Baltimore for an unsub who leaves victims unable to communicate.

When a young boy goes missing from his home in St. Louis, the BAU reinvestigates a similar cold case to search for the UnSub.

When prostitutes are murdered in Texas, their deaths seem to have religious overtones; members of the team are put at risk throughout the course of the investigation.

When a passenger jet crashes in Colorado, the BAU team is called to build a profile around the suspicious circumstances. The case hits close to home for Kate, who is reminded of a family tragedy.

The BAU investigates random murders in northern Virginia and searches for a conflicted UnSub who has an uncontrollable urge to kill but is also filled with remorse. Rossi receives a visit from a woman who could hold a secret from his past.

Women are found dead inside their own homes throughout L.A. The BAU searches security footage for an UnSub who was invited into each victim's home.

While Rossi conducts a profiling course on his birthday, he receives a call from his nemesis Tommy Yates, who discloses the location of his latest victim.

The BAU investigates when several young men and women are victims of disfiguring acid attacks. Also, Dr. Reid begins to settle into his new surroundings.

When a series of backyard pool homicides are reported in California, the BAU team searches for an UnSub with a puzzling past.

The FBI's assistant director of national security, Linda Barnes, joins the BAU as they investigate a quadruple homicide of a group of roommates in St. Louis.

The BAU investigates a string of murders taking place in supposedly haunted houses in Lewiston, Maine.