I tried to read this once before, when it was first published.  I honestly don't remember why I didn't finish it, I only read a few chapters before I stopped.  I do have this horrible occurrence of all my library holds coming to me in one huge chunk of literary amazingness, so I'm betting I just ran out of time on this one.
I'm so glad I gave it a second chance!  The first few chapters honestly don't really match the rest of the novel.  Isaiah is introduced and almost immediately there is the whole bad guy plots kidnapping, bad guy kidnaps, main character saves the day with a grenade launcher thing going on. I thought this would set the tempo for the rest of the book, but it honestly slows down from there.  Maybe that's why I put it down before, I thought is was going to be all over the top action and no real plot.  Boy was I wrong!
I enjoyed how Isaiah's and Dodson's back story was peppered throughout the book.  It makes a difference, knowing how they came to be in the life they are in.  How the two met and how they are tied together. 
The actual mystery was interesting, Isaiah had it figured out pretty fast, but the why definitely took longer than the how.  And the who.  
I finished the book, and immediately downloaded the sequel.  IQ wasn't perfect, but it was different and intriguing enough to keep me interested and invested in the characters.  I'd recommend this to anyone who likes a good mystery, a character that you haven't already met a million times and a setting that isn't usually offered in mainstream books.