Gears

When she was 11, Persephone D. Brass's parents were taken by the mysterious Gearcopters, never to be seen again. When she is taken in by a mechanical professor, she thinks her life could finally be normal again; dealing with friendship, schoolwork, and the professor's strict rules, and the underlying fear of what lies beyond the walls of her quaint town, the threat of the Gearcopters hanging over the citizen's heads.
Everything is normal.
Until the Gearcopters come for her, too...