Struggling with their relationship for over a year, a sudden family tragedy for Dani (Florence Pugh) keeps her together with Christian (Jack Reynor), who invites her along on a trip with his friends to Sweden to attend a once-in-a-lifetime midsummer festival.

What initially appears to be a carefree, peaceful and idyllic event soon becomes unsettling when Dani, Christian and their friends are invited to partake in increasingly unnerving and disturbing festivities, putting them at the mercy of this bizarre and insular community.