Question: The characters in the opera The Visitors are escaping the Black Death by sheltering in a villa outside what city
Sentence (from "The Visitors (opera)"): The libretto (like those for "Pagliacci" and "Ariadne auf Naxos") uses the device of a play within a play to reflect and intensify the relationships between the protagonists, who in this case are loosely based on characters in "The Decameron".
Relevant evidence: Yes