Michelle Bonilla

The 126 race into action when an armored truck and its guards are attacked by a group of masked men. Carlos, in his new job as a Texas Ranger, is assigned to investigate the case. Owen attends group therapy with Tommy to deal with his brother Robert’s death; Both Marjan and Paul each apply for the open lieutenant position, replacing Judd, who finds himself lost without his old job. Wyatt begins work at the call center and a major train derailment signals tragedy.

The 126 race to contain a toxic chlorine cloud of death unleashed by the train derailment; Owen names the station's new lieutenant.

The BAU searches for an unsub in Austin, Texas who is targeting prominent members of the community.

Cleo and Carla clash after Reese gets hurt while in Cleo's care. Weaver and Kovac cannot save the life of a developmentally challenged woman's only caregiver. Abby goes to a therapy session with Maggie. Later, Abby confesses to Maggie that she is afraid to bear children because they might be bipolar like her mother. Weaver tells both Carter and Chen that they will not be chief resident next year. Weaver is hurt to learn that Legaspi is already dating another woman. And Greene has a 7-year-old child abuse victim placed in protective custody, infuriating the boy's father Derek Fossen.

Grace and Carlos work together when they suspect a young woman was a victim of a black market organ trafficking ring; Owen’s brother Robert comes to visit and meet T.K., but surprises Owen with news that can affect the Strand family.