What is the importance of The Avalon in the novel, Wondrous Strange?

The Avalon is the theater in Hoboken where Kelley works. It is also a place in a Midsummer Night's Dream. Since everything in the play has a real location in the Otherworld and other Fae-owned locations, the Avalon is also an island that is reachable from the Tavern on the Green. Sonny shows this location to Kelley, telling her that it is the "wall" that separates the two worlds so that they can always communicate through it like the characters in the play talk through the wall.