What do you think the Phantom of the Opera sequel would be about?

There actually is a sequel, that Andrew Lloyd Webber is making into a musical that's opening on the West End in London in 2009. It's based on the book, "The Phantom of Manhattan", it's about what happens to Erik (the phantom) and what happens to Christine, and what happens about "them". I read it, it truly is magnificent. Note, this is the sequel to the stage version, NOT the original book, The Phantom of the Opera.