On a frigid, wind-swept lake, Ray Pelletier hunts for a quiet ice fishing spot, only to break through the thin surface and disappear into the cold water. Inside the lakeside cabin, his wife Helen Pelletier, their son David Pelletier, and David’s girlfriend Gina talk about life after college, imagining a future in the Peace Corps and a move to Uganda. The mood is calm but tense, as they weigh the practicalities of long-term plans against the immediacy of Ray’s fate.
The next day, the family drills through the ice while a silent observer watches from below—a presence that will shape everything to come. A separate family, Steve Cote and his son Stevie Cote Jr., sets up their own hole with a truck and a trailer. They glimpse something underwater and give chase with snowmobiles, but the creature remains elusive. The two families share a brief, wary social moment before resuming their day, each trying to normalize an extraordinary threat that lurks beneath the ice.
As they walk back to their respective fishing spots, the Pelletiers glimpse the creature heading straight for the men. Stevie Cote Jr. makes a
bold attempt to reel it in, but the thing drags him beneath the surface. The rescue effort by Steve is frantic, but Jr. bears a brutal wound on his arm that looks infected. Steve mutters that the creature seems to sense vibrations and is consuming everything in the lake, and he invites the Pelletier family to dinner as a way of sharing information and preparing for what might come next.
During the family dinner, Jr. grows increasingly disoriented, and his wound squirts blood onto Gina. They treat the wound, which appears infected, and Jr. insists that the creature has legs and is not merely a fish. The group urges Steve to take him to a hospital, but Steve refuses, implying that Jr. may not survive a conventional medical path and fueling a growing appetite for vigilance and retaliation.
Later, [Ray Pelletier], Steve, and David attempt to disorient the creature by running a motor on the ice. When Jr. emerges from the trailer and collapses, the creature drags him into the water. Steve dives in after him, but they both realize the boy is dead, and Ray then leaps into the frigid water to pull Steve to safety. The grim scene cements a resolve to leave, even as the night tightens its grip on the lake’s strange predator.
In the morning, they resolve to head out as soon as possible. They learn that Steve’s wound was caused by the creature, and it oozes with a troubling new discharge. Steve’s grief and anger mount as he talks about hunting down what killed his son, but the family steadies him and plans to depart at first light.
As they rest, Steve begins the snowmobile engines again to lure the creature out. He argues with Ray and then experiences the same disorientation that Jr. felt earlier. The creature attacks after David Pelletier steps out to see what is happening, and it takes Steve with it. Back in the trailer, David has a cut on his face, and Helen panics, trying to manage the crisis by suctioning venom from the wound. They hide inside the trailer, nursing their fear while a creeping threat lies just beyond the vehicle.
David’s relief turns to horror as the creature’s hand pushes through the floor lid and claws at him, cutting his throat and killing him. Morning light reveals the emotional wreckage: Gina reveals that she and David had planned to marry before joining the Peace Corps, and that they would have announced it the night before had events not spiraled so quickly. Ray grabs one of Steve’s guns, and the family makes their way outside as Steve’s remains loom large in their memories and the fear remains sharp.
They try to start the snowmobiles again, but the machines won’t respond. They hear a sound and realize Steve’s body has already been claimed by the lake’s creature, eaten underwater. A dark shape glides beneath the ice as the group continues their cautious retreat toward shore. Ray makes a final, desperate stand, trying to draw the creature away, but the ice buckles under his weight and Ray is killed, leaving Helen and Gina to face a future defined by survival and uncertainty.
The creature stalks them briefly, locking eyes with its two remaining targets. It studies them with unsettling calm before it turns away. Helen and Gina move toward the cabin together, their pace steady and resolute in the face of unfathomable danger. The ending leaves them walking side by side along the fractured ice, bravely choosing to keep moving, to trust each other, and to return to the warmth of the cabin even as the night looms large beyond the frozen lake.
