I've read where this is a lot of people's favorite of the 3 books currently, and I can understand why.  For me, this setting was everything! The Moors was eerie and dark and just what you expect from every horror movie ever.  I think it's easily my favorite portal world so far (though I think I'd love The Halls of the Dead just as much if we ever get to see that world fully).

I loved the characters and their relationships with each other.  They're so flawed, and the Moors are completely unforgiving when it comes to mistakes.