Russell and Mariel suffer a tragedy but it is made worse when Mariel tries to help. Kira feels guilty over an accident. During the hurricane and after there has been a mysterious military presence and Larkin tries to learn more about it. Meanwhile, Dave investigates a lost piece of jewelry.

The citizens start to question why the town is still under a quarantine that has cut off medical and building supplies. The citizens find themselves on the verge of a major medical pandemic. Russell and Sheriff Underlay must track down the source of this quickly spreading virus.

The family of Russell's friend and fellow Park Ranger, Carl, is struck by tragedy. Russell suspects Sheriff Underlay may be hiding something when he starts looking into the tragedy. Larkin calls upon an old flame to help her investigation into the military. Meanwhile, Mariel and Jesse have a big fight and Rose wants a tree house.

Larkin barely survives a car crash and the fate of her unborn baby is unknown. Larkin gets picked up by a stranger in a pick-up but she soon becomes suspicious of his motives. Meanwhile, Mariel tries to reconnect with Jesse.

Russel knowing that Larkin and their unborn child's life is on the line he must stop Larkin from reporting what she knows. Sheriff Underlay is shot and drifts between the past and present.

Russell and Underlay find that they have to work together as another storm is quickly approaching. They need to get their families out of Homestead and to try to find where Szura has stashed away the hybrids.