I'm going to avoid as many spoilers as possible but the general idea of this is that it's 90% filler. Act I and III are the only ones that deal with the core of the story and then the game ends abruptly. Act II is hunting down random members of a secret order that aren't even remotely interesting. Maybe one or two, but the rest are busy work. It's a shame because it's a setting we've wanted for a long time and it's by far my least favorite entry in the series.
