Hypothermia

A seasoned ice fisherman and protective patriarch who keeps his family close under pressure. He remains practical and brave, coordinating their defense against the underwater threat and guiding them toward safety even as the situation grows deadlier. His resolve is tested as the creature closes in, culminating in a fatal confrontation.

A calm, supportive mother whose priority is keeping the family together. She offers practical help and steady morale during the escalating danger. Her presence anchors the family as fear and tragedy mount around them.

Steve Cote's disoriented son, a curious and impulsive young man drawn into the sudden chaos. He suffers a brutal injury when the creature drags him, becoming a catalyst for his father's obsession with hunting the threat. His fate underscores the cost of underestimation.

The underwater predator haunting the lake, a silent stalker that can strike from beneath. It preys on vibrations and injuries, turning a tranquil fishing trip into a deadly siege. Its presence escalates the tension between nature and the families who dare intrude on its domain.

David's girlfriend and partner in future plans; she represents youth and hope, sharing dreams of joining the Peace Corps. She stays hopeful and close to the Pelletier family as danger mounts, illustrating human bonds that persist amid fear.

Ray and Helen's son, engaged to Gina and ready to start a life beyond college. He is determined yet vulnerable, caught in the deadly conflict and ultimately killed by the creature.

A hot-headed father who clings to a hunter's bravado, pushing for action against the creature. His stubbornness and grief drive risky choices that end catastrophically. He embodies the volatile edge of parental protection.