Campaign Seeds...

What if the Holy City told of in Revelation is something physical that comes to earth and exists here after the End?  What if it has a subterranean part!?  What if that's the place bad things are kept imprisoned?!

What about a real-world Neverending Story?  What if there is a dimension where mankind's fictional literary creations really live?  Nightmarish and gonzo....  Entire fictional worlds would exist as different layers of the plane.

What if the Ghost Hunters were actually dead.... as in GHOSTS.  But had no clue.