Captains Strand and Vega along with the members of the 126 are called into action to a county fair when a "Derecho," a series of fast-moving severe thunderstorms, hit Austin, causing hurricanic and tornadic-force winds, heavy rains, flash floods and a wide path of destruction. Owen's newfound passion for motorcycling puts him on a potentially dangerous path. Tommy has the potential for a romance when she meets an attractive single father. And as T.K. and Carlos prepare for their wedding, a secret from Carlos' past may stand in their way to happiness.

Captain Strand and the 126 race to the rescue when a woman is trapped in her mobile house that has been hijacked by her ex. Owen has a run in with former nemesis Sgt. O’Brien and is then questioned by the FBI. Tommy asks Grace dating advice. T.K. and Carlos meet with Iris Blake.

Capt. Strand reveals to the 126 he has been working with the FBI to help bring down a domestic terrorist group with his Austin motorcycle club/gang The Honor Dogs, then race Owen to respond to a bomb threat at the State Capitol and put a stop to the terrorist deadly plans.