Boy (Bill Skarsgård) is a young man who must confront the deranged matriarch of a corrupt post-apocalyptic dynasty that left him orphaned, deaf, and mute. After a tragic childhood, an enigmatic shaman (Yayan Ruhian) transforms him into an instrument of vengeance and releases him into a distant dystopia on the eve of the annual massacre of dissidents. Seeking his place, Boy joins a resistance group while having intense conversations with the ghost of his rebellious younger sister.