A horror comedy following what appears to be a perfectly ordinary British family who travel to the remote Swedish island of Svalta for a summer holiday, hoping to experience a local festival known as Karantän, which commemorates the island’s dark history of quarantine, starvation, and rumored cannibalism. As they arrive, the family encounters hostility from the locals, unsettling rituals, and an atmosphere of creeping menace that suggests they may be in serious danger.