A murder investigation leads to Garcia delving into her hacker past -- and reconnecting with her former love.

When frozen bodies are found in Nevada floating in water, the BAU’s investigation leads them to suspect that the victims were part of a cult that could be behind the deaths. Also, JJ confronts old demons from her abduction and torture last year.

When shooting victims are found in the Los Angeles area with possible links to criminal activity, the BAU searches for a vigilante UnSub.

When bodies are discovered in public places throughout Boston, the BAU investigates whether a taxi or ride-share service the victims used before their deaths could lead the team to the UnSub.

When former team member Prentiss tracks an international serial killer, she enlists the help of the BAU when she believes the UnSub's next victim will be on American soil.

The BAU investigates if bullying may be the link between two high school students who are the sole survivors after both of their families are killed.

Morgan lends emotional support to Garcia when she experiences anxiety over a case that is personal to her from her past.