I have been in a bit of a reading slump so a fun thriller was exactly what I needed to clear my brain a bit. Cas' math skill reminded me a bit of my favorite skill in the video game Disco Elysium (visual calculus) and I loved the dynamic the author crafted between our protagonist and the other. While the book could have used a bit more depth, I am super optimistic about the next few books being just as entertaining and maybe even scratching my Cas-makes-friends-and-interacts-with-people-who-she-isn't-going-to-kill itch.