A hurricane is quickly approaching a small town in Florida leaving the residents little time to prepare. When the hurricane finally hits, many of the residents' lives are in peril. Rose, one of the town's smallest residents notices some mysterious lights in the heart of the hurricane. Meanwhile, after the storm, Dave discovers some mysterious skeletal remains.

After discovering an Air Force officer named Paxton in a wet suit and barely alive at the ranger station, Russell begins to question what befell the man when he notices his wounds are identical to Dave's. But Russell soon finds out that he's not the only one interested in Paxton when Sheriff Underlay and Larkin both begin to question the man's mysterious circumstances. Meanwhile Mariel finds something unexplainable protruding from Paxton's wounds, Russell's curiosity about the strange skeleton grows, and Underlay continues to push for a town quarantine.

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.

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.

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.

A family of Cuban refugees tries to make their way to Miami. After they notice the lights in the water, their escape from Cuba is cut short. The next morning Russell encounters one of the Cuban survivors. Meanwhile, Mariel attends a support group and Larkin realizes that someone is following her.

Russell and Dave investigate what's happening on Szura's island in the Keys. Tensions rise at school between the students who were changed by the hurricane and those who weren't. Underlay tries to find out the extent of the military's involvement in post-hurricane changes.

Sheriff Underlay tracks down a mother who has abandoned a baby at Russell's ranger station. The mother denies that the child is hers. Her mother-in-law swears that the baby is her grandchild and that Christina has been acting strange ever since the hurricane hit. Meanwhile, Mariel who begins questioning why she has been losing touch with her kids makes a shocking discovery in the water.

Russell is suspected of committing a double murder. Larkin discovers Russell's criminal history and wonders about who he really is. Mariel insists that she saw a body in the water and demands that the bay be dredged.

After a visit to Mariel, Russel finds that Tom has taken the children on a vacation without asking permission. Someone is hiding outside of Mariel's house and is discovered by Russel. Larkin is suspicious of Russell's intentions towards Mariel.

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, Larkin and Dave find out the identity of one of the creatures. Meanwhile, Underlay tries to find out who shot him and Kira begins to wonder what really happened to her dad.

Kira is curious and frustrated as she tries to find the truth out about her father, Mariel and the other residents of Homestead. Will Kira find danger in her search? Meanwhile, Russell tests Mariel's blood and they are shocked at the results.

Russell and Tom team together to try to catch a pregnant Christina and Derek, who are armed, dangerous and on the run. While searching Russell and Tom find a group of migrant workers. Mariel confides in Jesse and Rose about what happened to her. An unconscious Kira is in the hospital after her encounter with the orange being. Larkin searches for more answers about Paxton and his real reason for being in the area during the hurricane.

Mariel begrudgingly performs an ultrasound when Christina demands to know what is growing so quickly inside of her. After the school reopens, Jesse is bothered by the way; some of the fellow students are acting. Russell and Dave investigate what Healy knew about the hybrids.

After his investigation of the hybrids, Russell finds that he may be out of a job. Sensing another storm, the hybrids prepare. Rose's teacher is teaching a subject that has Russell bothered. Jesse and a school friend find a way to get even with the hybrids.

In the middle of the hurricane chaos, Underlay and Russell mount a rescue of the humans who are being round up by the hybrids. Meanwhile, two humans who suspect that Underlay is the cause of the chaos take Larkin, Dave, Jesse and Rose as hostages.

After a couple reads his blogs, they abduct Dave to find out what he knows about the hurricane's aftermath. Underlay and Sirk discover the identity of the woman in the bay and Sirk gets a glimpse of the orange lights.

Russell confronts Mariel about the changes in her personality. Tom tries to help Sirk cope with his new circumstances. Jesse meets an intriguing girl at the hotel while on vacation with Larkin and Rose.

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.

As the hurricane starts to hit the town of Homestead, Russell and Tom try to stop Szura. The National Guard rounds up Larkin, Mariel and the children. Mariel and Larkin have suspicions about their rescuers. Dave is questioned as to Underlay's location.