On a restricted side of a Utah mountain, Dr. April Sommers is leading a team of scientists to develop a new breed of spider, pushing the boundaries of their research in a setting that feels edgy and tense. A new teen arrival to the ski resort, Chad, challenges Dan “Dash” Dashiell to a race down the mountain, sparking a clash between a restless younger energy and a retired Olympic skier who has already paid a heavy price for danger. Dash, aware of the risks, reaches a large rocky slope and turns back, choosing a safer route down rather than risking a leg injury that could end his career. When he finally reaches the bottom, he encounters Sommers and the two begin to talk, the air thick with the weight of what they’re undertaking. This moment of conversation foreshadows a deeper connection between science and peril as the resort’s calm begins to crack.
As the day unfolds, a chilling turn arrives inside the lab. Sommers returns to the lab only to find dead scientists scattered across the space, their work undone in ways that hint at a catastrophic failure. The sole survivor is cocooned in a web, a haunting sign of the danger that has escaped containment. He warns Sommers that the spiders are breaking free, and then he dies slowly, his last breath a grim cue that the mountain is about to Enter a new era of danger. The lab’s last surviving creature—a mutated black widow—attacks Sommers, driving her into a locked office where she sounds an alarm and draws the attention of Professor Marks and Captain Baker, who are elsewhere on the mountain. The warning comes too late to stop the spread, and the scientists find themselves racing against a threat that grows hungrier and more aggressive with each passing moment.
Back at the lodge, Ranger Rick Dickerson enlists help to track two missing hunters. Dash joins the search as they locate the hunters’ truck and a mutilated elk, which Dash suspects bears some of the scars of a predator rather than a simple animal encounter. The pair then discovers the body of one hunter and, further along, the other hunter cocooned in a vast spider web. A terrifying moment follows when Rick is snagged by a web and dragged toward a lurking spider, a scene that ends with Rick’s death as Dash watches in horror. The driver’s seat becomes a frantic escape as Dash hot-wires the still-running truck and tries to get away from the nightmare they’ve uncovered.
Meanwhile, inside the lab, Professor Marks, Captain Baker, and a squad of soldiers storm the compound to confront the looming threat. They find Sommers, who begs them to listen to her warnings about the danger lurking in their work. Inside, the spider launches another brutal attack, killing a soldier, and Sommers seizes crucial records of the experiment. The documents reveal that Marks had knowingly accelerated the spiders’ growth, making them larger, faster, and stronger; but the price is an insatiable hunger and a resilience to the cold, a combination that makes extinction or containment extremely difficult. Sommers realizes her goal was never just about armor, but about harvesting spider webbing for new ideas—an ethical border that she now regrets crossing. She flees back to the lodge, carrying the dangerous knowledge with her.
When Sommers returns to the lodge, she and Frank witness chaos as the spiders attack a growing number of guests, including the ski coach who had been guiding the teens. The situation spirals as more people are killed in the parking lot, and the teens hide in a shed, with Frank and Sommers racing to keep them safe. Chad, taking the keys, drives the bus in a desperate bid to escape, but a black widow—having snuck onto the bus—slides across the windshield, and Chad crashes the vehicle into a snow bank. The teens’ peril intensifies as the danger closes in from every side, forcing them to rely on wit and courage to outlast the impending assault.
Dash returns to the hotel and begins to coordinate a defense. He and Sommers search the basement, only to have a spider slip inside. They stun it with a fire extinguisher and lock it away in the basement, hoping to limit further damage. In the lobby, a spider slips through the chimney and kills two guests, a brutal reminder of the chaos unleashed. Dash then takes decisive action, impaling the creature with the antlers from a mounted deer head, a stark image of nature turning against those who dared to meddle with it.
On the hijacked bus, Frank checks on the kids and discovers one of them is unconscious. They brainstorm a way to escape as the black widow tries to gain entry. Frank improvises a plan and traps the spider, allowing the terrified kids to flee. Frank’s heroism is rewarded by the timely arrival of Captain Baker and his squad, who help secure the immediate area and rescue the remaining passengers.
Back at the lodge, Dash devises a final, high-stakes plan to contain the threat. He communicates with Captain Baker over a radio, proposing a trap that uses the landscape itself to channel the danger. Dash marches out with his skis, drawing the spiders toward a snowboard half-pipe that Baker and his team have blocked off. Johnny then positions himself near an avalanche cannon, waiting for Dash’s signal. At the half-pipe, the plan comes to life: the spiders are corralled, and Johnny triggers the avalanche cannon, causing a controlled explosion that wipes out the arachnid threat in a dramatic, devastating display.
In the aftermath, Professor Marks, who had earlier opposed killing the spiders, confronts Dash on the slope. He charges at him in a final act of defiance, only to fall to his death along the half-pipe, consumed by the last remaining spider, which is then killed by Baker’s rifle fire. The mountain finally seems to quiet, but the relief is short-lived. A government agent arrives with a small force to erase any trace of the spiders, instructing survivors to remain silent and suggesting that the official explanation for the events will be a spill of hallucinogenic chemicals. The mountainside is left with a carefully crafted cover story, while those who witnessed the terror must decide whether to speak out or stay quiet, knowing that some secrets are better kept buried beneath the snow.
