Full review to come. But I have three things to say: 
 (a) The real rating is 3.5. Goodreads, you need to bestow upon us the ability to use half-stars. Just update already. Sheesh. 
 (b) The first quarter and last quarter of this book deserve five stars, but I can't ignore the wedge in the middle that left me stone cold. Seriously - the beginning hooked me, and I was so rapt by the heart-pounding pace of the last few chapters that I was literally talking to to the book. It was the hundred and fifty pages in the middle that bored me to death. 
 (c) The acknowledgements made me tear up. Granted, I am in a place in my life where literally anything will push me to tears (the other day I watched Salt and cried when August Diehl got shot) but this was for real. You gotta read the bit about Rick Yancey's dog. I was bawling. 
 Brb, cringing.