Some people really like this book and some people don't as much, but I really did absolutely love this book. It reminded me so much of V.E. Schwab's Vicious and Vengeful, but also of McGuire's Mira Grant pseudonym (of which I've only read Into the Drowning Deep). But it was dark and gritty, but also fun and sci-fi. And sibling-focused development always gets me because I have a really great relationship with my sister. I just loved it.