Owen Strand, the lone survivor of his Manhattan firehouse on 9/11, takes his progressive philosophies of life and firefighting down to Austin, Texas, where he helps the firefighters of Firehouse 126 start anew.

The crew races to a disaster at a wave pool, and an outbreak of mercury poisoning that is leaving its victims in a a zombie-like state. Meanwhile, Owen must come to terms with his illness and what the side-effects of treatment may do to his vanity. Also, Michelle follows a new lead on her missing sister while TK is unsure how to handle his budding relationship with Carlos.

Judd calls out Owen's preferential treatment of T.K.. Marjan feels ostracized at her new mosque after another rescue video goes viral. Owen helps Michelle uncover new information about her sister's disappearance.

A massive tornado sweeps through Austin, as Owen, Michelle and their teams race to save those in its path.

The crew race to a brawl at a male strip club, a fire at a bull semen factory and a protest where male toxicity is taken to a new level; Grace tries to reconnect with Judd; Owen faces the consequences of his chemo.

The crew deal with a runaway bull at a used car lot and an apparent electrocution at the hands of an LA transplant; Michelle gets the strongest lead yet on her missing sister.

The crew race to a rattlesnake infestation, and attempt to rescue a man with dementia from a dangerous scene he created; Michelle learns the truth behind her sister's disappearance; A tragic accident shakes the crew to its core.

Owen and the 126 crew race to a gender reveal party gone horribly wrong, and a father/son trapped in a cave during a spelunking excursion. Meanwhile, Owen helps T.K. reconcile the past to help his future, Judd and Grace aid Judd's aging father.

Owen helps T.K. reconcile the past to help his future; Michelle learns the full truth about Iris.