This is a better turn for the series, getting away from corporate or spy shit and giving us an old-style drug problem to work through. :) 
 I knew it was coming from the end of the previous book, but to see all the horrible issues of the soldier potion for zombies turn her into a self-serving self-destructive zombie who had Just started getting her life together was a very pleasant move. It was going too easy for Angel. The personal agency stuff needed a big kick in the ass, and I'm so happy it happened this way. 
 Zombie life is interesting enough on its own. :) 
 Total brain candy. Literally. Yummy Brains. :)