Shadowsinger: The Final Novel of The Spellsong Cycle L. E. Modesitt Jr.

Secca, foster daughter of the Soprano Sorceress, and now her successor as Sorceress Protector of Defalk, must deal carefully with her willful master and wield her power to save his kingdom from the armies, fleets and master sorcerers of the Maitre of Sturinn. Faced with seemingly insurmountable odds, she is forced to test her own powers over and over again, while teaching her new husband and her inexperienced apprentice the skills they will need to aid her in creating spells powerful enough to shake the foundations of the world.