Starminster: The City of Wings

Take flight to save the secret city in the sky, in the heart-stopping finale to the soaring Starminster trilogy. London Overhead, the secret city hidden in the stars, is the only place where Astrid has ever felt at home. But when the enchantments protecting it mysteriously start to glitch, the safety all of the Librae who live there is threatened. As the grown-ups abandon the city, Astrid refuses to give up her wings and go back to her old life on the ground.
It's up to Astrid and her friends to save their home, but they'll have to unravel the darkest secrets of London Overhead, before time runs out, and the magic is gone forever.