One of the things that happens in Book 10 is the Kariad are revealed.
I had originally envisioned the Kariad as renegade Aurelians, who had rejected their culture’s goal of subjugating and exterminating humanity and who were instead trying to help. Unfortunately, their well-intentioned interventions invariably fail.
I am thinking about decoupling the Kariad from the Aurelians, and portraying them more in the manner of a Star Trek: TOS type of super-powerful alien intelligence (“You are to us, as an amoeba is to you,” that sort of thing.)
We’ll see where it goes.
I also have to think of a funky way for them to talk.
Aside from that, Book 10 is going to be a mélange of economics, Shakespeare, and pornography. I know those are the key plot elements, but the actual plot is still taking shape. It may end up sort of like Book 5, where there isn’t really a plot, just a lot of stuff that happens.