Cort is a 13-year-old boy living on a houseboat in the swamps of Alabama. He possesses extensive survival knowledge passed down from his river-guide father, but he currently struggles with feelings of isolation following his mother's recent departure. He feels increasingly disconnected from his peers at school, missing basketball practices due to his remote living situation. Despite his young age, the approaching hurricane forces him into a position of intense physical and emotional responsibility.

Cort's father is an experienced river guide whose family roots trace back to Creek Indian ancestors in the Alabama swamps. Following his separation from his wife six months ago, he becomes distracted and unreliable, prioritizing his attempts to win her back over his daily responsibilities. While he teaches his son valuable outdoor skills, he currently struggles to provide the emotional stability and attention Cort needs.

Liza is Cort's tough, practical classmate and childhood friend who lives in a brick house on the hill above the river. Following her own father's death five years prior, she has begun withdrawing from her previous outdoorsy lifestyle to focus on typical teenage activities. She remains brave in dangerous situations and maintains a deep, complicated connection to the river environment where she grew up.

Cort's mother is a woman who grew dissatisfied with the difficult, isolated life on the river and the demands of being married to a river guide. She recently moved into town seeking a different lifestyle, triggering the central emotional conflict between her estranged husband and son. Her absence casts a long shadow over the family, directly causing Cort's father's distraction.

Francie is Liza's young little sister. She is highly dependent on her family and easily frightened by the severe weather and sudden power outages. When the hurricane separates the children from the adults, she requires constant physical protection and reassurance from the older teenagers.

Mrs. Stovall is a widowed mother living in a sturdy brick house on the hill above the river. She owns the land where Cort's houseboat is moored and maintains an arrangement where Cort's father handles property maintenance in lieu of rent. She provides Cort with food and a sense of domestic comfort that he lacks on the houseboat.

Catfish is Cort's loyal pet dog, originally a stray that Cort and Liza found in the woods years ago. He serves as Cort's primary confidant, listening to the boy's frustrations about his broken family when he feels he has no one else to talk to. The dog is deeply attached to the houseboat and becomes highly anxious when forced to leave it.

Jason is the wealthy, popular captain of the middle school basketball team. He represents the normal, socially integrated teenage life that Cort feels excluded from due to his isolated living situation on the river.

Curly Stanson is the local sheriff responsible for public safety in the region. He delivers the official evacuation warnings, making it clear to the locals that state emergency services will not be available to rescue anyone who chooses to stay behind during the storm.

Rusty is a massive, highly aggressive wild boar displaced by the hurricane floods. Weighing hundreds of pounds, he acts territorially on the small patches of high ground, posing a severe physical threat to anyone trying to take shelter in the area.

Elmo is a wild bear fleeing the severe floodwaters of the hurricane. Taking refuge in the upper branches of a tree at the Indian mounds, the bear acts as a silent, intimidating presence that severely limits the teenagers' ability to move to safety.

No-name is a large, old alligator residing near the ancient Native American mounds. A difficult and dangerous creature to catch, the alligator demonstrates the sudden, violent reality of the swamp environment to Cort.

Hoss is one of the clients who hires Cort's father for a night hunt on the river. He uses a deep-sea fishing rod to hook a massive alligator during their excursion.

Jim is a client on the guided river trip. He handles the rifle to shoot the alligator once the creature is brought to the surface by Hoss.