When the bodies of several married couples are found with multiple stab wounds, the BAU travels to Detroit in search of the killer. After an autopsy reveals that the couples were forced to stab each other to death, the team theorizes that their UnSub's rage was triggered by his own failed marriage. When the UnSub starts only kidnapping women, the team must figure out why he changed his MO - and whether or not they still have time to rescue his latest victim. Meanwhile, Blake's husband returns from overseas and asks her to take a full-time job teaching with him at Harvard.
