An ice storm hits Austin. Owen deals with the fallout of the 126 closing and Tommy, T.K. and Nancy settle into new employment. Judd and Grace prepare for the birth of their first baby.
The ice storm continues. Tommy, T.K. and Nancy race to rescue a young boy stuck on a lake. Judd and Mateo help a trapped Paul and Owen takes drastic measures to save a man who has been stabbed.
Owen's date with the chief of staff to the governor of Texas goes awry. The 126 responds to a house fire and realises the couple's daughter is missing. Judd meets a teenager who has a profound impact on him.
In an attempt to bond with Wyatt, Owen and Judd take the teen alien hunting, but their search takes a different turn when they find two dead bodies. Tommy joins a grief group for widowers.
A dust-up between Owen and an obnoxious police sergeant goes viral, leading Owen to decide they will settle the score on the softball field. Grace competes against a hot shot night-shift operator.
Owen and T.K. travel to New York to say their goodbyes to Gwen but the plane experiences a mechanical failure. T.K. reflects back when Gwyn helped get him into rehab years ago.
The members of the 126 spring into action when a surprise military homecoming erupts into chaos. Owen is left responsible for taking care of a talkative pet. Paul faces a medical emergency.
The 126 race to the rescue when a medieval-themed restaurant suffers carbon monoxide poisoning. The crew is worried that Paul still has not mentally recovered from his surgery. Mateo is offered a promotion by his old fire captain.
The 126 race to the rescue when Catherine receives a package at the governor's office that may contain a bio-hazard. Grace and Carlos team up to investigate a prank 9-1-1 call that turns deadly.
Owen fears the past is back to haunt him when a stalker targets him and Catherine. Tommy and Nancy face consequences when Nancy saves the life of a woman wearing a "Do Not Resuscitate" bracelet.
The members of the 126 race to find, and then save, a mystery victim in a car crash. Owen faces a crisis in his relationship with Catherine. Carlos is surprised when he meets T.K.'s AA sponsor.
Owen and the 126 race to emergencies all with one common element tying them together. Tommy's brother-in-law makes a surprise appearance in Austin and Marjan confronts Owen about his anger management issues.
Owen has a breakthrough during therapy. After a call, Grace reaches out to a coworker but regrets it when Judd offers more than she was planning. Tommy, TK and Nancy race to help a survivalist injured by a reptile.
Owen travels to Los Angeles to confront his estranged father and some painful childhood memories. Judd takes Wyatt to his family ranch where an emergency brings them closer together.
The 126 respond to emergencies when a man falls into a trash compactor and a frantic mom tries to rescue her kids in a runaway car. Tommy and Julius grow closer.
The 126 come together when one of their own is trapped after a building explosion. Owen reflects on his 9/11 experience, TK and Carlos come to a decision and Tommy and Julius decide on their future.