Dune Messiah - Frank Herbert
I found the first sequel to Dune to be a big letdown. The majority of the book is people just explaining the plot to each other, with most of the characters behaving nothing like they did in the first book. I get that a lot of this is intentional, Paul is frozen by destiny, he is unable to make any choice at all because he is trying to avoid disasters he is foreseeing. The disasters are actually happening though, billions are dying in a jihad.