This is the second novel from the writer made famous by Gone Girl. It is another dark whodunnit thriller with lots of horrible murders. Having read her other two, I thought that I knew who the murderer was straight away (hint: I had assumed the worst), but I was wrong. It was cleverer and more complicated than that, but I did guess who did it eventually. Flynn gives you just enough clues to work it out before she tells you, and I quite like that.
This is set in the USA Midwest, again. Our protagonist is a woman with mental health issues, again, and the murders are horrifying and involve children, again. So, it is safe to say that Flynn likes to keep to a theme. She also likes her female characters to have a shocking evil streak, which I also quite like. The story is a grim and sad one, there is closure at the end, but there was never going to be a happy ending.