Florida, 1935, and the residents of Heron Key are preparing for the Fourth of July barbecue, little realising how much their world is about to change. Domestic helps Missy and Selma are dismembering the alligator that tried to snatch the baby Missy was watching, before they can get ready for the party.

Henry, a returned soldier from WW1, is hoping that his comrades in his construction team will not disgrace themselves in front of an already fiercely judgemental community. Hilda Kincaid, is squeezing into a frock, wondering how she will face another night of public humiliation as her husband toys with Doreen from the golf club. And Sheriff Dwayne Campbell - laughing stock since his wife gave birth to their mixed-race son - is squaring up to deal with any troublemakers and prove he can control the town, even if he can't control his wife...

Tensions simmer at the party and in the early hours of the morning, a woman is found half-beaten to death. As whites turn on blacks, the finger of suspicion points at one man. And while wild accusations are made, far over the Atlantic a tropical storm changes direction and turns towards Florida, increasing in speed by the second. As the hurricane beacons are lit along the Keys, the town folk prepare themselves as they always do, unaware that the approaching storm is beyond anything they have ever experienced. In one night, Heron Key will change forever.