It is only when John Doe explains his work that we see how truly slick the slide into madness can be. And to director David Fincher's credit he never feels the need to make it all better for us in the end.
It looks like Nathan Fillion might be playing a superhero afterall. After being considered for roles in Green Lantern, and Captain America,Fillion (most remembered as Malcolm Reynolds in the cult-hit Firefly) is reportedly in final negotiations to play Dr. Hank Pym in the new Avengers film. It hasn't been stated whether Pym would be Ant-man in the film, or just a S.H.I.E.L.D. scientist, but we're holding out hope.