** spoiler alert ** 
 I so rarely give books five stars, but it was SO RIDONKULOUSLY GOOD. 
 Now if I may attempt to return to some kind of form and explain what I loved about this book. I won't bore anyone with rehash. Read the summary if you want to know what the book is about. 
 How about characters? Cleave has a way of letting you in on each character's past that is not unlike peeling an onion. Layer by layer, he reveals the inner workings until you're deeper inside than you realize. In a few chapters, we feel like we know Tate, Adrian, Emma, even Cooper. We're supposed to kind of hate Tate, the way Schroeder does, but also respect him for his knack for solving cases. Adrian is a pitiable character, one I could feel sorry for... is he just confused and maybe not really very bright? Or just evil? You know how Buttons says, there's a difference between crazy and mean? I don't know which one Adrian is. Maybe a little of both. Even the invisible character of Melissa X from The Cleaner is exposed and we learn more about who she is and why she kills men in uniform. This is a story line that I hope Cleave continues. Cooper was a surprising character that I first liked and felt sorry for, then felt cheated, disappointed and angry once the innocent persona of the professor was peeled back and we saw him for what he truly is. A rare moment of surprise for me. 
 How about twists? This book is a winding mountain road. So much evil, so little time to write about it, and how each story line is intricately weaved into another (even one from a previous book, which... YAY!)is literary genius to me. I like to guess at what the outcome will be, and be happily surprised when I am wrong. 
 How about pacing? Pretty sure I almost had a heart attack. Collecting Cooper is written from two POV's. This story could not have been told the right way had we not been able to read both Tate and Cooper's thoughts. The book covers just a few days, however there is near nonstop action, through which we alternately follow Adrian trying to build or complete his 'collection' and Tate trying to find Emma Green, Cooper Riley and by default, Adrian. 
 I often wonder what happens in the mind of a writer of grisly tales of evil, abuse, hate, mental illness, cavalier responses to torture and murder. I admit now that I don't really want to know. I just want Paul Cleave to keep it coming. 
 Loved loved loved this book, in case that wasn't obvious.