Valente, Dominique. Starfell #4

Starfell is on the edge of disaster. The fight against Silas, the wizard determined to steal all magic for himself, is far from over, but how can Willow make a difference when her powers have been taken? With the help of her friends, the young witch sets off to the treacherous Mountains of Nach. There, she hopes to find the Craegun, a powerful beast believed to restore anything that has been lost, for a heavy price. The mission is fraught with danger, but there's no turning back or the magic of Willow's world will be lost forever