Claudia Gray 
Sorceress 

The triumphant conclusion to New York Times bestselling author Claudia Grays dazzling Spellcaster series.To save the lives of countless people in Captives Sound, Nadia swore herself to the One Beneathto black magic. Her plan, and the towns only hope, is for Nadia to learn enough sorcery to strike back against the forces of evil. But now that shes separated from her friends, her family, and her Steadfast, Mateo, Nadia is more vulnerable than ever to the growing darkness.The final battle lines are drawn, surprising alliances are made, and true love is tested in the action-packed conclusion to the breathtaking Spellcaster series.