Dani and Christian are a young American couple with a relationship on the brink of falling apart. After a family tragedy keeps them together, Christian invites a grieving Dani to join him and his friends on a trip to a once-in-a-lifetime midsummer festival in a remote Swedish village. What begins as a carefree summer holiday soon turns sinister as the insular villagers invite their guests to partake in festivities that grow increasingly unnerving and disturbing.