The Smith family's much-needed vacation to the remote Swedish island of Svalta takes a dark turn when they arrive during preparations for a mysterious local festival that celebrates a dark history. Unsettled by the unfriendly locals and strange rituals, they try to make the best of their trip, stubbornly enjoying the island₂s isolation and natural beauty. However, as the festival looms closer, the family realizes something far more sinister is unfolding especially when they discover that a serial killer is on the loose.