Things have changed for 17-year-old Zoe ever since the dramatic events that brought her together with the mysterious X took place. To save Zoe and her family, X did the unthinkable - he won their freedom by giving himself up to captivity in the Lowlands forever.

But being back in the Lowlands has its advantages. It gives X the chance to discover his past, which could be the key to breaking the Lords' hold on him for good. Little does X know that Zoe has a plan to reunite them ... one that will see her risk her life and bring her perilously close to losing all that she and X are fighting for.

Gripping and full of heart, this epic continuation of Jeff Giles's series, which already has rave reviews from Oscar-winning director Peter Jackson and New York Times bestselling authors Cassandra Clare and James Dashner, will bring readers right to the edge of everything.