Falcon Quinn and the Black Mirror by Jennifer Finney Boylan

Falcon is an oddball kid that doesn't really fit in. One day he gets on a bus and it takes him to a magical island where everyone is a monster. It's a school for monsters and Falcon will soon discover things he never knew before. Filled with mystery, humor and suspense.

Two big 12 year old thumbs up!
Ideal for kids 12+