Tell and Wren face a wraitha sorcerer gone roguein this third and final book in the Children of the Black Glass middle grade fantasy series thats Howls Moving Castle meets Christopher Paolini!Wren, a captive in the evil sorcerer Deserts house, learns Desert has grown even more terrifyingshes melded herself into a human body to become a wraith. Yet, even though she now wields more power, more strength, and more magic than ever before, Deserts still not satisfiednot until she consumes Wrens too. Tell, separated from his sister for the first time in his life, will stop at nothing to save Wren, and while he lacks magic himself, he discovers one of their friends has mystical sorcerer powers and is as determined as Tell is to save Wrenthe girl who once saved him. It will take quick wits, mountain training, and sorcerer allies old and new to vanquish Desert once and for all. Failure would mean losing the city of Halfwayand each other.