The 126 crew responds to a military tank on the loose in downtown Austin and a human pile-up at the roller derby. Meanwhile, new paramedic captain, Tommy Vega, joins the team and Owen is reunited with his ex-wife and T.K.'s mother, Gwyneth, and receives an update on his cancer.

A bank robbery, an apartment fire and a pregnant woman lost in a parking garage are the seemingly unconnected calls to which the 126 responds. Then, T.K. celebrates his one-year anniversary of sobriety, while Owen and Gwyn may not make it to the end of the week as a couple. Also, Carlos finds himself working on a case with his Texas Ranger father.

The 126 make calls to a bloody disaster at an ice cream shop and help rescue a boy missing from his own birthday party. Meanwhile, the 126 holds an "intervention" for Owen after he accidentally spills his secrets to new roommate Mateo. Then, T.K. and Carlos take a big step in their relationship, as Grace learns to rely on others in the aftermath of the car accident.

The members of the 126 spring into action when a surprise military homecoming erupts into chaos. Meanwhile, Owen is left responsible for taking care of a talkative pet, Paul faces a medical emergency and Tommy goes on her first date since Charles' passing.

Owen and the 126 race to emergencies at a fast food drive-thru, a high school wrestling match and a case of road rage - all with one common element tying them together. Meanwhile, Tommy's estranged brother-in-law makes a surprise appearance in Austin, and Marjan confronts Capt. Strand about his anger management issues.

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 into action when a horse barrels into a brewery with an unconscious rider on its back and then to a bus full of tourists all experiencing seizures. Judd introduces Owen to Wyatt's mother Marlene. Carlos and T.K. start couples counseling, when Carlos investigation into his father's murder becomes all-consuming.

The 126 race to save a man crushed under a vending machine. While struggling to handle his aggressive foster horse, Owen finally faces the truth of his brother's death. As Mateo and Nancy scramble to delete a nude photo of her accidentally sent to the 126, Tommy is concerned that Nancy may be facing a possible health scare.