What I liked about this book was that it was told from the perspective if the "chosen one" ended up being killed, and another had to take his/her place. Mo is the substitute for her friend Verity, who happened to be The Vessel (aka the chosen one) to keep all the magic in check. Only she died, and someone had to replace her ASAP. It kind of reminded me if Harry died, and Neville taking his place (thanks, DHP2 for giving me inspiration!).
Other than that though, the book was rather....lame.The writing was okay, but nothing to really ooh about. The heroine was pretty wimpy throughout most of the book, and near end actually grew some backbone - character development! Even so, I was confused as to who she got two romantic interests when all she died was whine and complain, with her other positive assets being merely told than shown. Her two relationships consisted of her bickering, with hardly any substance at all. I also thought the world building was weak - I didn't really understand what was going on about the Arcs and the way the magic worked.