For me, this book really suffered from the 'middle book syndrome'. An awful lot of it felt like it was filler intended to show the growth of the relationships between the chracters, which is okay and necessary but was allowed to run somewhat rampant in this case. 
 I still enjoyed the story and got through it pretty quickly, it's a very fast read. I like Derek's slow evolution from the gu that didn't even spare Chloe much of a second glance to the one determined to protect her at all costs. Contrary to this, I didn't really like Simon, the other romantic interest. He's there and somewhat too friendly and nice during the good / easier times, but he's never there during the bad times. He is, of course, straight back by Chloe's side to comfort her once the danger's gone. I wonder whether the author purposefully wrote Simon as artifically sweet to make sure that her readership preferred Derek?