This book has some great characters and a good plot so I am slightly surprised to be giving it three stars but the truth is I didn't enjoy it as much as I had hoped, mainly because it has some annoying flaws.
The main flaw in the later parts of the book is that even when things finally get going the action is interspersed with long sections of very boring and un-necessary dialog. The characters will be frantically escaping some impending threat and then suddenly find they have time for a nice long repetitive chat. This tends to spoil the flow, completely destroys any tensions and slows things down quite a bit so I'm not sure why the author kept doing it.
Its doubly annoying because a lot of the book is quite slow, bordering on boring, so when things do start to happen near the end of the book you are expecting quite a lot and its failure to deliver thus seems doubly annoying.
Whilst I'm on the flaws I also found the main characters behavior pretty inconsistent. He's presented as being highly intelligent yet when it suits the plot behaves like a champion idiot, completely ignoring the bone ring is a good example of this. The result is that the character and his behavior often seems a little contrived for my tastes.
Its still a good book but I've read far better this year so whilst I would recommend it I wouldn't say its a required read.