Prospero is introduced in the time of the Red Death, a ravenous plague that is devastating his kingdom.
Prospero believes that he and the nobles of his kingdom can escape death. Therefore, Prospero invites all wealthy, unaffected people in his domain to his castle for a grand masquerade ball.
As guest arrive, they are bewildered and amused by the grandiose rooms that Prospero has created. Each room, beginning from east to west, is marked by a different color. The last room, black with red windows, is so disturbing that no one enters. Even more mysterious is a large ebony clock within the room, which chimes every hour, halting the exaltations of the party.