The importance of the setting is that everyone is at the festival while Montresor lures Fortunato away. No one is around to see them and if someone were to be they wouldn’t know who’s who. That sets the scene for the story of revenge. “I vowed revenge”(1). When they meet in the street alone it gets the ball rolling for the crime. “I met Fortunato in the street, alone”(3). Finally, everyone thinks they’re friends, so they wouldn’t do anything to each other.
Costumes symbolize