Jade is a 17-year-old high school senior and school janitor living in the small town of Proofrock, Idaho. She uses an encyclopedic knowledge of 1980s horror films to interpret the world around her and process her trauma. Dressed regularly in work coveralls and combat boots, she intentionally cultivates an intimidating exterior to keep her peers at a distance. She closely monitors her community for signs of a real-life slasher scenario unfolding.

Letha is a wealthy arrival from the Terra Nova development and one of the only Black residents in Proofrock. She possesses a pristine appearance, athletic grace, and natural kindness. Despite her privileged background, she shows genuine compassion toward her socially isolated classmates and asks probing questions about their well-being.

Sheriff Hardy acts as the primary law enforcement officer for Proofrock. He maintains a gruff, strict demeanor but demonstrates clear protective instincts toward the local youth. He spends much of his time patrolling Indian Lake in an airboat to enforce water safety rules.

Mr. Holmes is a soon-to-retire history teacher at Proofrock High School. He shares a cynical perspective on the town's shifting class dynamics with his students. He allows his students to explore unconventional historical narratives, grading Jade's extensive essays on slasher movies.

Tab is Jade's father, a man struggling with debilitating alcohol addiction. A past car accident left him with severe physical scarring across his face. He spends his days drinking heavily with old high school friends while completely neglecting his household responsibilities.

Kimmy is Jade's mother who abandoned her husband and daughter. She works as a cashier at the local dollar store. She maintains a physical presence in Proofrock but completely ignores her child during their brief passing encounters.

Theo is an affluent developer establishing a home in the Terra Nova community. He commands an aristocratic presence among the newly arriving elite. He frequently entertains on his private yacht and expects deference from the local working-class residents.

Tiara is Theo Mondragon's much younger second wife. She enjoys the luxurious amenities of her husband's wealth. She attempts to act as a comforting presence for her stepdaughter as they settle into their new rural environment.

Known to Jade only by his yellow aviator sunglasses, this construction worker helps build the Terra Nova development. He shows kindness to Jade on a freezing night. He carries guilt regarding an accident that occurred on the job site.

Rexall works as a school janitor and frequently drinks with his old friends. He exhibits highly inappropriate behavior around the high school girls. He receives public credit for heroic actions that he did not actually perform.

Deacon is a key financial backer of the Terra Nova housing project. He possesses a performative, outgoing personality. He routinely ignores local safety ordinances by shooting flaming golf balls into Indian Lake at night for entertainment.

Stacey Graves is a central figure in Proofrock's local folklore, commonly known as the Lake Witch. According to town legend, she is the spirit of a part Indigenous American girl pulled from the depths of Indian Lake by a tow truck hook decades ago.

Sven is a young Dutch tourist exploring the American West. His spontaneous decision to take a nighttime boat ride in a borrowed canoe initiates the terrifying events on the water.

Lotte is a Dutch tourist traveling across America. She uses her smartphone inside a plastic bag to document their ill-fated canoe ride across the dark, foul-smelling water.

Meg works as Sheriff Hardy's secretary at the Proofrock police station. She manages administrative tasks, handles incoming calls from the community, and tries to keep the office running smoothly.

Tiffany is a local teenager in Proofrock who attends parties with her peers. She frequently documents local events on her smartphone and observes the social dynamics of her graduating class.

Clate is an older resident of Proofrock who socializes with Jade's father. He carries the heavy social stigma of having been present during the tragic drowning of the sheriff's daughter years prior.

Melanie was Sheriff Hardy's daughter who died in a boating accident on Indian Lake. Her death traumatized her father and fundamentally shaped his current overprotective policing style.

Greyson is a construction worker who helped lay the foundation for the Terra Nova homes. He fell into an underground cave system at the job site, an incident the Founders paid his coworkers to cover up.