Related to that though, the build-up to the Hunter/Mulder/Scully section was amazingly well-written, I felt. Ideas of multiple universes, and of those universes bleeding over into each other is very intriguing to me...

Yes, I'm with you here. And somehow the concept seems to fit very well into the X-Files universe. Maybe it's that whole post-modern concept of never being sure what really happened? It seems only a short jump into the other ways that things could have happened.