I could have easily given this 2 stars, but as a J. K. Rowling fan, I can't give her less than 3. This book starts out strong - very entertaining and it grabs you, but the middle was boring, boring, boring. By page 300, I was so bored, I thought about stopping. Instead I skipped ahead and read the last two chapters, which is where they answer the whodunit question. The ending was partly predictable and part of it made me roll my eyes.
My favorite out of the three novels was The Cuckoo's Calling and the series just went downhill after that. The series has become very formulaic, which leaves me feeling very disappointed. I wish Mrs. Rowling would go back to writing YA Fantasy because that's where her talent shines.