Played by Skarsgård, the character “Boy” swears revenge after Hilda Van Der Koy (Janssen), the insane matriarch of a corrupt post-apocalyptic dynasty, murders his family, leaving the youngster speechless, deaf, and orphaned. Motivated by his inner voice—which he appropriated from his beloved old video game—Boy trains under an enigmatic shaman (Ruhian) to become a death tool before being released on the eve of the yearly extermination of dissidents. As Boy unleashes vicious martial arts mayhem, causing a deluge of destruction and bloodletting, chaos follows. Boy eventually joins a desperate resistance group while attempting to orient himself in this hallucinogenic world and arguing with what appears to be the spirit of his disobedient younger sister.