A Swedish businessman named Tomas is on a family vacation at a luxurious resort in the French Alps with his Norwegian wife, Ebba, their young daughter Vera, and their preschool-aged son Harry. On their second day there, while enjoying a meal outdoors, they witness a controlled avalanche. The snow cloud rises ominously towards the deck, creating a panic. In a moment of fear, Tomas, who is recording the scene on his phone, abandons his family and flees as the deck empties. Meanwhile, Ebba is left behind, enveloped in a dense fog with their children. Fortunately, as the fog lifts, it turns out no one was harmed.
Later that evening, they dine with one of Ebba's friends, who has brought along an American man. While recounting the avalanche incident in English, Ebba reveals her frustrations about Tomas’s cowardice. Tomas, embarrassed, insists he did not flee from the table and adds in Swedish that "one cannot run in ski boots." The dinner descends into an argument, leaving their guests awkward and uncomfortable. Ebba feels betrayed by Tomas's refusal to acknowledge his actions, which deepens the rift between them.
Determined to take a break, Ebba chooses to go skiing alone. In the company of her friend, she confronts her about her own reckless behavior regarding relationships, questioning if she truly values her family. Her friend, advocating for an open relationship, sends Ebba into more introspection about her own marriage.
The following day, one of Tomas's old friends, Mats, arrives at the resort with his girlfriend, Fanny. They share an uncomfortable dinner, where Ebba again recounts the avalanche incident, causing tension amongst the group. During conversations, Mats brings up the idea that people are different during crises, referencing real-life disasters. The evening takes a turn when Ebba decides to show everyone the video of the avalanche. Tomas reluctantly concedes that he does appear to be running away, leading to speculation about his true motivations during the event. Mats feels insulted when Fanny suggests he might act similarly in a crisis, which leads to a heated argument between them.
As the ski lift ascends in silence, Mats encourages Tomas to express himself through primal screaming, which leads to a moment of catharsis for Tomas as he confronts his deep-seated feelings of inadequacy and cowardice in front of his children.
On their final day, as they prepare to leave, the fog thickens again. Tomas takes initiative, instructing the children to follow him while Ebba trails behind. When she gets lost in the fog, Tomas briefly abandons the kids to find her, which he does, returning with a smile.
The journey down the mountain takes a chaotic turn when Ebba, feeling that the driver is incompetent, panics and demands to leave the bus. Mats steps in to organize the group, ensuring women and children exit first. The tension escalates as they all exit and make their way down the winding mountain road, and amidst the chaos, Tomas succumbs to temptation and accepts a cigarette from a stranger, much to Harry's surprise, who questions his father's sudden change of behavior after a smoke-free vacation. As the family’s dynamics shift, each member grapples with their relationships and the aftermath of the incident, leaving the resort forever altered.
