I really don't know how there can be 55 books in this seris and it's still good. I mean, is it world shattering new stuff that revolutionizes the genre? absolutely not. It follows a very known formular, but still, there is suspence in every book so far (at least for me) and the interactions are nice and the secondary characters are interesting, so is Eve, as a really kickass FMC and the storyline is actually decent... really impressive for a 55th book.