I just started watching the new season (after another binge of the previous 3) and a lot of the characters current situations and disposition (even that of the current state of Neptune) all seem to follow after the books themselves. Like the fallout between Veronica and Weevil (who were in a friendly place in Season 3 and the movies). He mentioned taking a payout behind the Mars' backs over the corrupt cop thing which is directly from the books. I guess since the books picked up after the movies that's why the new series follows after the books? But what if the new viewers never read the books? A lot of the connections are (so far) not explained.