Um wow (fans face). I really enjoyed this book. Harper and Knox definitely kept things interesting throughout the entire book. I literally couldn't put it down. 
 Harper is a very powerful character. I said it once and i'll say it again, I love a strong female lead who doesn't take crap from anyone. Due to people constantly letting her down Harper put up strong walls around her heart, she brushes everything off her shoulders with humor. And she can be downright hilarious at times. The way she banters back and forth with Knox was really entertaining. Underneath all the humor though is a strong individual with a huge heart. She is constantly surprising Knox as well as the readers with her responses to situations throughout the book. Where you'd think she would be resentful or hateful she shows compassion and forgiveness, which really says a lot about her character. 
 Knox is also a powerful and dominant character. I don't use the word dominant lightly where he is concerned (fans face again). He demands your attention throughout the entire book and lets face it, he's sexy as hell, pun intended ;). 
 I love how the author played out the entire demon aspect. Two people as a whole living in one body fighting for control. I've never read anything like that and getting glimpses of the demons control was really entertaining.