McCurdy, Janelle: Mia and the Lightcasters

Mia always dreamed of being an umbra tamer until she met the wild creature on the Nightmare Plains. Since that day, she prefers to stay safe within the walls of Nubis. Safe, that is, until a surprise attack. With her parents captured, Mia's only hope is to travel to the City of Light to find help. But with only her little brother, two friends and one solitary tamed umbra, the journey feels impossible. Mia not only has to overcome her fears, she also has to learn to harness her umbra taming abilities if they are to complete the quest in time.