Hypothermia

Ray falls through the ice while searching for a fishing spot on the lake. He struggles in the freezing water and manages to surface, but the exertion leaves him exhausted. The incident sets off a tense sequence that leads his family to search for him later.

Inside the lakeside cabin, Helen, David, and Gina talk about their plans after college. They discuss joining the Peace Corps and going to Uganda, mixing everyday worries with a sense of the unknown ahead. The scene establishes their relationships and future ambitions.

The Pelletier family rushes outside to search for Ray, who has passed out from exhaustion after escaping the lake. They bring him back to the cabin and attempt to care for him while he recovers. Ray awakens and insists he is fine, though the tension among them remains.

The creature that lurked beneath the lake watches the family from the depths. It observes their routine with a quiet, ominous stillness as they settle in for the night. Its presence foreshadows the danger that will unfold.

The next day, the Pelletiers drill holes in the ice for fishing. The Cotes bring their truck and trailer and set up nearby, briefly socializing with the Pelletiers. The group briefly spots the underwater creature and the men attempt to chase it on snowmobiles, but it escapes.

While walking back to their hole after the socializing, the Pelletiers catch sight of the creature heading toward the men. Jr. is suddenly dragged down into the water, leaving Steve and others in shock. Steve carries Jr. into the trailer, tending to a deep gash that appears infected.

Steve invites the Pelletier family to dinner at the trailer. Jr. grows disoriented and his wound squirts blood onto Gina. They tend to the wound, but Steve refuses to take Jr. to the hospital, implying the situation will be handled at home.

To disorient the creature, Ray, Steve, and David run a motor on the ice. Jr. comes out of the trailer and collapses as the creature drags him back into the water. Steve jumps in after him, discovers his son is dead, and Ray then dives in to rescue Steve.

With dawn approaching, the family decides to leave as soon as Steve is ready. Steve's infected wound continues to weep and he rants about hunting the creature. The fear and fatigue simmer as they prepare for a potential escape.

That night, Ray, Steve, and David attempt to lure the creature by starting the snowmobiles on the ice. David steps outside to check what is happening and the creature attacks, dragging Steve away. The threat grows as the remaining family braces for further danger.

Back in the trailer, the creature's attack leaves David injured and alone. As he lies on the floor, the creature's hand pushes up through the lid in the floor and claws at him, killing David. Helen hears the commotion and panics.

In the morning, Gina reveals that she and David planned to marry before their Peace Corps service. Ray grabs Steve's gun and the group heads outside, hoping to attract the creature, but the snowmobiles fail to start. They notice Steve's remains are not present, realizing the creature has claimed him, leaving a chilling trace under the ice.

They glimpse the creature's shadow swimming beneath the ice as they move toward shore. Ray urges Helen and Gina to reach safety while he stalls the threat. The creature rams the ice, causing it to crack and Ray is killed in the fall.

The creature stalks Helen and Gina, then stares them down before it retreats. The two women stay calm and walk toward the cabin together, hoping to reach safety despite the lingering danger under the ice.