Oh, boy, was it good!
Really, I wouldn't classify this as YA... it has a "flavour" of a classical fantasy.
The language was almost lirical and the story very interesting: how could two races, which hate each other and are natural enemies, forge peace? Marrying the heirs, of course! It is not a marriage arranged by the parents but by the heirs themselves! Great idea!
Maybe the YA label was given because the heirs are young, but it is often so in fantasy novels...
We are speaking of shapeshifters here and the races are birds and serpents. Mortal enemies in nature, but as Zane, the heir and then kind of the Serpiente, says:
"Serpents and birds are not meant to live together," he asserted again, "but I personally like to believe that we are more than our animal counterparts."
Danica, at the beginning of the book agrees too:
I could not look into the eyes of a boy terrified of death and shaking from pain and feel hatred. This was a life: serpiente, yes, but still a life; who was I to steal it?
I thoroughly enjoyed this book with its deceptively slow pace, tender budding love story and interesting intrigues. :D