I'll be shocked if Louis is the "big bad" for the next season. After all, how else will they be able to bring their next super duper guest star in for the next season?
I'm set for a big reveal, even though I really don't feel like this season deserves it. The great thing about Rita's death is that it was the icing on the cake of a majestic fourth season. This season doesn't really feel like it's earned the right to go out with a bang especially since so much of it has just had that feeling of "going through the motions" and had the feeling it just going to peter out.
I should probably shut up and just enjoy whatever they throw at me if it makes this season even slightly worthwhile