"The Music of the Spheres" is a series set in the combined universes of "Batman Begins" and "Superman Returns." It posits a situation where Superman and Batman are the only costumed heroes in the world, meeting for the first time. A few key notes:
--The series begins very shortly after "Superman Returns" (technically, the first meeting takes place in the middle of the movie) and very shortly after the as-yet-unknown events of the second Batman movie. Batman has been active for about three or four months now. --The series takes "Batman Begins" as its departure point. "The Dark Knight" was released after the series started, so those events don't happen as they do in the movies (in the case of Harvey Dent, they're quite different).