The Red Queen (Only part two of The Sending - see below for details)

The post-apocalyptic fantasy series reaches its heartbreaking, world-shaking conclusion
Award-winning Australian author Isobelle Carmody concludes the epic story of Elspeth Gordie, a heroine in the vein of Tamora Pierce's most memorable and empowering protagonists. The final chapter in the eight-book Obernewtyn Chronicles, "The Red Queen" is a YA fantasy novel decades in the making.
After years spent struggling to balance her desires with her responsibilities, Elspeth Gordie has fully embraced her role as the Seeker. Battle-scarred and lovelorn, haunted by memories of her beloved Rushton, Elspeth is not prepared for what she finds at the end of the black road she travels: the Compound, a lost community with a startling secret. As Elspeth strives against her captors, she learns that Rushton and her friends have fallen into the hands of the deadly slavemasters that rule the Red Land. And worst of all, as Elspeth stumbles, the Destroyer creeps ever closer to his goal: awakening the cataclysmically destructive weaponmachines that Elspeth has been charged with stopping. Has all her sacrifice been in vain?
Full of romance, action, and suspense, "The Red Queen" is a worthy finale to such a breathtakingly elaborate series.