When a BAU member gets in trouble in Mexico, the team enlists the services of the International Response Team for their help.

The BAU investigates the cause of several fatal car crashes involving drivers and pedestrians. Also, Reid gets bad news.

The BAU investigates when several young men and women are victims of disfiguring acid attacks. Also, Dr. Reid begins to settle into his new surroundings.

When three women in New York City are found dead with several bones broken, the BAU works with a single mother (Tatum O'Neal) who believes that her son is behind the heinous crimes. Meanwhile, Reid faces a difficult decision after a fellow inmate is threatened.

When two drastically different murder sprees are committed in Burlington, Vermont, the BAU concludes that a serial killer suffering from sleepwalking is responsible for both crimes. Meanwhile, Alvez presents Shaw with a shocking ultimatum after Reid is assaulted in prison.

The BAU investigates an urban vampire who kidnaps his victims at night and holds them underground in the sewer system; Reid makes a difficult decision in prison.