So I've started reading Night Watch by Terry Pratchett, and this one seems so much more somber in tone than the other handful of books I've read so far. Yes, there's still humor, but it seems less light-hearted. Then again, I've just started and haven't read much.
So, anyway, I thought I'd ask other Discworld readers - do you notice a difference in tone with the various books? Also - has Terry Pratchett ever done a run-down of events both personal and societal that influenced the tone of his writing? I'm sure there's a Discworld reference book of some sort?