The BAU team investigates a string of brutal bludgeonings in Philadelphia and is led to the city's boxing scene in search of the killer. Also, Hotch makes a connection with an attractive runner as they both train for a triathlon.

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.