I already loved Duncan, from his first appearance in Trudge and thereafter. So my review is admittedly biased.
I want to start with Charlie. Charlie is an awesome character. He cares deeply for his friend (Duncan) and it shows. Chesser throws in a healthy dose of humor into his character which makes him even more likable. Charlie's moral strength cannot be overstated.
Now on to Duncan. His character is so well written, which I already expected from the previous books in the series but you never really know, so it was nice that my expectations were exceeded. Duncan is very relatable, with flaws, demons, empathy, an unbending sense of right and duty, and some really awesome, and occasionally off color, humor.
I really enjoyed reading his backstory and the events that he endured prior to his introduction in Trudge. I will be completely heartbroken - probably even cry - if or when Duncan dies or is killed.
I do admit that I am very curious as to what becomes of Nate (Charlie's cab driver) and kind of hope we see him again.
This book was well worth the purchase and I highly recommend it.
Also, this book can be read prior to Trudge (the first book in the series) without spoilers to the following books. If you aren't already a fan of Chesser or familiar with his work, this book would be a great introduction to his work.