I really liked the overall idea of this book, but the execution left a lot to be desired. I loved the tie-in to Norse mythology established in the beginning of the novel. We learn about raven history, their connection to humans, and their love of riddles. We also learn about the magical torc and how it tempted the raven Huginn with immortal life if he would eat the flesh of his human amicus, making him the first of the evil valravens.
We then come to the present day where our protagonist, Gabriel, lives with his Aunt Jaz. Gabriel is more or less an orphan, his mother died when he was young and his father has been missing for the past several years. Shortly before his twelfth birthday, Gabriel's aunt gives him journals that belonged to his father and he learns about how his father became the amicus of a raven. Eventually Gabriel's own skill with riddles allows him to become the amicus of the raven Paladin and the two learn to communicate and even join together in one body. These two, together with Gabriel's friends Pamela, Abby, and Somes, search for the lost torc in order to rescue Gabriel's father. To save him the group must journey to Aviopolis, an underground city inhabited by birds and currently ruled by Gabriel's uncle Corax who has become an evil half-human, half-valraven.
I'm sure middle-grade readers will love this book. It's full of magic and riddles and moves along at a great pace. While the plot is interesting and inventive, I think the characters fall a little short. Gabriel doesn't have much personality and his character development is minimal. Pamela is similarly shallow, and although Abby and Somes have are a bit more unique, they are still very one dimensional. The adult characters aren't any better and even though it seems unimportant, I still can't understand why Aunt Jaz just allows Trudy (Pamela's mother) to march in take control of the house. For some reason that detail really bothered me, and we don't learn enough about either character to explain it. This was still a fun novel and I wouldn't hesitate to recommend it to younger readers.