I've jumped in this world as if I, too, where made for this! I loved the monsters, the mysteries and the back story of this outcast family and I really enjoyed discovering all the codes of this organization... the story is fast-paced and I've read it with impatience but... I don't understand the end... if it's not a serie, there's no way you can let the reader with so many open questions (and theories)!!!! 
I give it 4 stars because there are some childish comments here and there I really felt had no place in the story... but overall that was a good read!!