Masque is a horror film loosely based on the Edgar Allan Poe story. With plague raging outside his castle, Prince Prospero gives refuge to a few lovely village maidens before locking his doors to all others. Inside the castle Prospero indulges in sadistic torture and incestuous pleasures with his sister, Lucretia. The princess is jealous of Prospero's obsession with Julietta, the loveliest of the maidens. Outside, the remaining villagers want to seek refuge from death and storm the castle. Prospero will not open his doors to death and cruelly fends off the villagers. To amuse himself and his guests, Prospero makes plans for a masked costume ball. At the ball, there is one uninvited guest.