This book has everything I could have wanted in a police procedural mystery: a likeable and flawed detective with a family mystery in his past, a good partner, and a nemesis in the department as well as a terrifying and creepy killer. In fact, Hayder goes above and beyond in the killer department. Way above and beyond. 
 There were many a point in this book that I was cringing, but each gruesome detail is totally worth it and, although it's grotesque and horrifying, the violence never feels gratuitous. The mystery is solid and just perfectly twisty enough, and Hayder's writing style is descriptive without being flowery and straight to the point without being too clipped. I'm really excited to read more of her work.