It took me a really long time to read this book, partially due to schoolwork and partially because it just wasn't really gripping me. It was entertaining, but not enough so to where I agonized over not being able to sit down and read it. 
 The general idea of the book is good and I like that the historical aspect of the book is one that I've never heard of before: the thirteen treasures of Britain. It's good to see something new out there, as there's only so many times you can rehash the same things over and over again. 
 It's just that the book is kind of hampered by extremism. The book has a lot of sex and violence, possibly in an attempt to differentiate this from Scott's youth oriented Nicholas Flamel series. Now I should say that it's not that I mind sex and violence in books- it's just that this all felt unnecessary and overly done. It's not just "sex and violence", it's "SEX! and VIOLENCE!" with capital letters and exclamation points. While Scott and Freedman do make this part of the plot, it's just done in such an extreme and overly dramatic fashion that it just loses the impact it would have had if everything had been toned back just slightly. (Not that I think they should've been removed, just toned down a smidge.) The NF books are no stranger to violence (although they don't really show sex), so Scott already knows how to blend violence and fiction together well. I'm just puzzled as to why he felt like he needed to give a double shot of it here when a single shot would have been just as effective. 
 Now if the characters had been a little more developed, I probably wouldn't have cared as much about the overdone sex and violence. But they weren't. We're given bare bones about the characters, just enough to keep them from being flimsy but not enough for them to stand out above the rest of the book. Owen and Sarah just end up fading into the background in a sea of more well developed and interesting characters. I know there's more books forthcoming to flesh these characters out, but I'd have liked them to be more intriguing now and for them to stand out above secondary characters that may or may not show up in the next book. (Trying not to spoil the "who lives and who dies" thing for anyone who hasn't read the book.) 
 Overall though, this was a decent read and I like that the book had both an ending as well as an opening for the next volume. I'm slightly curious to read the next book, although I'm not going to rush out to the stores to get it as soon as it releases. I guess that in the end I'm just disappointed because I know that Scott can and has done better in the past. This was good, but Scott will really need to step the game up in the next book. I enjoyed this, but this wasn't exactly the breakout adult novel it needed to be. 
 (For parents: READ THIS BOOK BEFORE GIVING IT TO YOUR KIDS. There's a lot of adult material in this book. There's sex, violence, some violence during sex, references to drugs, references to BDSM, references to rape, and descriptions of violence.) 
 (ARC provided by Amazon Vine)