The Silhouette (Alan Quinn and the Second Lifes)

As far back as Alan Quinn can remember, his family has been on the move. Australia, Brazil, London, Germany; they've never been anywhere for very long. But, when his family settles in the small town of Ashton, Kansas, Alan feels like he can finally call a place home. That is until his father runs away, his mom gives up on the search, and Alan is left to investigate.
Together with new friends, the LeCarre's, a new dog, Peaches, and a new ally, Darius, who seems to know more than he leads on, Alan is brought closer to the answers he seeks, but a species his father only described in the stories he told has been awakened, leaving Alan to discover what is hiding in the shadows: The Silhouettes.