The Wall and the Wing: Bk. 1 by Laura Ruby
Strange stories and creepy characters unite in this most weird and wonderful adventure of the year. In a vast and sparkling city where nearly everyone can fly, 12-year-old Gurl is trapped. Orphaned and lonely, she believes she is nothing more than a flightless leadfoot, until one fateful night, when she discovers that she has the power to make herself invisible. But even with this newfound talent, Gurl can't hide from a giant rat man with a taste for cats, a manipulative matron with a penchant for plastic surgery, and a belligerent boy named Bug. Gradually, Gurl learns to control her power and teams up with Bug to figure out who and what she is. Their quest takes them on a wild ride where they confront mind-bending monkeys, an eccentric genius with a head full of grass and a pocket full of kittens and the handsome but lethal Sweetcheeks Grabowski - the gangster, who holds the key to Gurl's past and the world's future!