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.

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.