Lucas (Mads Mikkelsen) is a member of a close-knit Danish community and works at a local kindergarten. Divorced, he struggles to maintain a relationship with his teenage son, Marcus (Lasse Fogelstrøm), who lives with his ex-wife, but enjoys wholesome interaction with the children at the kindergarten. His coworker Nadja (Alexandra Rapaport) makes advances towards him and eventually moves in as his girlfriend.
One of the kindergarten pupils is Klara (Annika Wedderkopp), the daughter of Lucas' best friend Theo (Thomas Bo Larsen). Drawing on memory of a pornographic picture her brother showed her, she makes comments that lead the kindergarten director to believe Lucas indecently exposed himself to her. When interviewed with leading questions, Klara gives unclear testimony against Lucas. The adults in the community believe the director's story of abuse, dismissing Klara's later contradictions as denial.
Lucas is shunned by the community as a pedophile sexual predator. His friendship with Theo is destroyed, the pressure causes him to break up with Nadja, and his son is publicly ostracised. The kindergarten staff ask leading questions of other children at the kindergarten, who also "admit" to being abused. However, the children's accounts mention details of Lucas's basement, which supports Lucas's innocence, as his house has no basement. After a hearing, he is released without charge.
The community is still suspicious of Lucas, and the ostracism turns to violence. His dog, Fanny, is killed, a stone is thrown through his window, and he is beaten by grocery store employees when he tries to buy food. On Christmas Eve, Lucas confronts Theo during a church service. Later, Theo overhears Klara apologizing to Lucas as she drifts off to sleep. His doubts about Lucas' innocence are resolved, and he visits him on Christmas Day with food and alcohol as a peace offering.
A year later, tensions in the community have lessened. Lucas and Nadja are in a relationship again, and Lucas' son is accepted into the local hunting society as an adult. On a hunting expedition to commemorate the event, an unseen person shoots at Lucas. Blinded by the setting sun, Lucas is unable to identify his attacker, who reloads but flees.