A model-influencer couple get a ticket to the luxe life when they are invited aboard an all-expenses-paid cruise alongside a coterie of the rich and ghoulish, but an act of fate turns their Insta-perfect world upside down. Pushing each provocative set piece to its outré extreme, Östlund maps the shifting social hierarchies with the irreverence of a modern-day Luis Buñuel and the incisiveness of a cinematic anthropologist