Gideon, Hotchner and their team head to Mexico to aid in the investigation of a serial killer who preys on the elderly.

The Behavioral Analysis team initially faces resistance from local law enforcement officials, whose investigative techniques differ greatly from those used by the team in domestic cases. However, when another person is murdered, the two factions join forces in order to track down the killer before he strikes again. Meanwhile, Hotchner is torn between life at home with his wife and newborn child and his responsibilities at work.