The BAU is called to San Francisco to investigate a possible Zodiac Killer copycat. Meanwhile, Reid wonders what he's done in his life as he reaches 30.
The BAU team searches for a serial rapist in Houston known as "The Piano Man" who has resurfaced and is assaulting his previous victims. Also, Prentiss tries to come to terms with her trauma from last year and with rejoining the team.
The BAU team investigates a series of brutal home invasions and murders in California's Inland Empire that appear to be gang-related, but their investigation may uncover a more sinister motivation.
When married couples fostering young children end up being killed in Seattle, the BAU team looks for an unsub with a maternal-yet-murderous instinct. Also, Garcia fears a possible proposition from Kevin.
When an Oregon woman is found dead in an abandoned asylum, the BAU realizes that the victim is part of a series of gothic, ritualistic murders and the suspect might be a Satanist.
The BAU searches for Morgan's cousin in Chicago when his sister Desiree is injured in a car accident after chasing a car presumed to be carrying his cousin.
New deaths upon the heals of a serial killer's execution initially seem intent upon spreading doubt that the true killer met the bullets of the firing squad.
The BAU joins Agent Rossi as university guest lecturers, scheduled on the same day as Rossi's long-term annual commitment to visit an imprisoned serial killer.
In this first part of a two-part season finale, the BAU encounters a gang of bank-robbing serial killers in the nation's capital. As the team tries to negotiate the situation unfolding inside a bank, one of the team is taken hostage.
In part two of the season finale, the BAU races to understand the ultimate goal and core dynamic of the remaining Face Cards and their design in keeping Will captive and alive.
The BAU is asked to investigate when 4 unconnected men go missing without trace. When the body of one victim is found the evidence just adds to the mystery.
The BAU heads south to investigate a fast-moving UnSub whose signature matches that of a serial killer from 30 years ago. Also, the team learns that someone is tracking their cases and replicating crimes the BAU has solved.