An unexpected arctic cold front brings an ice storm to Austin and a variety of weather-related emergencies. Meanwhile, Owen deals with the fallout of the 126 closing, as Tommy, T.K. and Gillian settle into new employment, and Judd and Grace prepare for the birth of their first baby.

As the unexpected arctic cold front and ice storm continues to cause havoc in Austin, Tommy, T.K. and Gillian race to rescue a young boy who has fallen in a frozen pond. Judd and Mateo work furiously to help a trapped Paul, and Owen takes drastic measures to save a man who has been stabbed and left for dead.

As the unexpected arctic cold front and ice storm continues to cause havoc in Austin, Owen works to rescue the lives of the stranded migrants; T.K.'s life hangs in the balance and Grace prepares for the birth of her baby.

Grace is caught in the ice storm as she goes into labor, and Judd, Owen and Tommy race to find her.

Owen's first date with the beautiful and accomplished Chief of Staff to the governor of Texas goes awry. Meanwhile, the members of the 126 arrive at a house fire and find a couple's young daughter is missing. Then, 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. Meanwhile, Tommy joins a grief group for widowers, as mysterious events around her house lead her to believe Charles is communicating from the beyond with her and the twins. Then, a woman fears she is cursed and takes drastic measures to cure herself.

When a dust-up between Owen and an obnoxious police sergeant goes viral, the existing tensions between police and fire rescue mount, leading Owen to decide they will settle the score on the softball field. Meanwhile, Grace competes against a hot shot call center night-shift operator when he moves over to the day shift.

When T.K.'s mother, Gwyn, has an emergency, Owen and T.K. travel to New York. But the flight is anything but smooth when the plane experiences a mechanical failure. Meanwhile 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. 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, Tommy & the 126 race to the rescue when a medieval-themed restaurant suffers a case of carbon monoxide poisoning. Meanwhile the crew is worried that Paul still has not mentally recovered from his surgery and his friendship with Marjan is over. Mateo is offered a promotion by his old fire captain, but quickly realizes he is not the man he once knew.

Owen and the 126 race to the rescue when Catherine receives a package at the governor's office that may contain a bio-hazard. Meanwhile 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. Meanwhile, Tommy and Gillian face consequences when Gillian 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. Meanwhile, Owen faces a crisis in his relationship with Catherine. Tommy goes on a first date and Carlos is surprised when he meets T.K.'s AA sponsor.

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.

Facing his anger management issues, Owen has a breakthrough in therapy. Then, after a particularly devastating emergency call, Grace reaches out to a co-worker, but regrets when Judd offers more than she was planning. Also, a clown has an emergency at a young boy's birthday party, and Tommy, T.K. and Nancy race to help a survivalist who has a painful encounter with a reptile.

Owen travels to Los Angeles to confront his estranged father and some painful childhood memories. Wyatt acts out and prompting Judd to take him to his family ranch where an emergency brings them closer to together.

9-1-1 Lone Star on vauhdikas ja jännittävä draamasarja, jossa seurataan Austinissa, Teksasissa sijaitsevan asema 126 pelastushenkilöstön elämää. Edelisen kauden tapahtumat johtivat aseman sulkemiseen ja henkilöstö sijoittui eri puolille kaupunkia. Kolmannen kauden alussa Austiniin iskee yllättävä kylmä rintama jäämyrskyineen aiheuttaen laajamittaista kaaosta. Pystyvätkö kapteenit Owen Strand ja Tommy Vega pelastamaan kaupungin, ja onnistuvatko he saattamaan asema 126:n jäsenet taas yhteen?