The BAU travels to Houston to investigate a series of murders that have occurred near construction sites and abandoned buildings. Because the murders appear to be random, the team believes the killer could be a homeless person. Meanwhile, everyone is noticing an apparent change in Reid's behavior.
Elizabeth Prentiss, a foreign ambassador and SSA Emily Prentiss' mother, seeks the aid of the BAU when a Russian immigrant is kidnapped and held for ransom.
The BAU is called to investigate after the bodies of missing people are discovered in a remote region of the Idaho wilderness. The gruesome find also leads the team to determine the unsubs have been hunting humans for sport.
When homeless persons begin going missing mysteriously from the streets in Kansas City, a local detective calls the BAU to investigate the disappearances.
When the prolific serial killer Frank returns and murders Gideon's girlfriend, Gideon takes off to find him without telling the team where he is going. The BAU must then profile Gideon as well as Frank to find both of them.
An elite team of FBI profilers analyze the country's most twisted criminal minds, anticipating their next moves before they strike again. The Behavioral Analysis Unit's most experienced agent is David Rossi, a founding member of the BAU who returns to help the team solve new cases.