I thought it was a pretty brave choice, narratively speaking, to set the whole book up as a search for Slado, and then just completely drop that thread and spend a big chunk of the end of the book exploring the demons and their unexpected sophistication. I think it worked and I didn't think about it much at the time, but in retrospect, that's a move that could have come off as just completely losing the plot thread.

The hints of some kind of lost technology from the first two books (routine bioform clearance etc) is a kind of intriguing, but that plays less of a role in this book. I like that slow burn multi-book storytelling, but I was kind of hoping that that thread of the series would be explored more. This is presumably something that will come back into focus in the later books. Again, it feels like a brave move to more or less drop progressing that strand of the story for a whole novel. I think it worked, because the mystery of the demons is a pretty strong story itself.