The magical world of Artimé is gone and the Unwanteds are looking to Alex Stowe for answers, but while his twin brother Aaron continues to build his army in Quill, a very dangerous common enemy is revealed.

In a society that purges thirteen-year-olds who are creative, identical twins Aaron and Alex are separated, one to attend University while the other, supposedly Eliminated, finds himself in a wondrous place where youths hone their abilities and learn magic.

As the Wanteds, Unwanteds, and Necessaries struggle to adjust to changes in their society, Mr. Today begins training fourteen-year-old Alex to replace him as Artime's leader one day while Alex's disgraced twin, Aaron, connives to take over Quill.

When they are separated at sea, mouse siblings Clarice and Charles Sebastian, who were taught to be careful, must now need to be bold if they are to survive-- and keep their promise to find one another again.

As the greatest army ever assembled in the seven islands flies to the land of the dragons, everyone's mind is haunted by the same thought: Thisbe Stowe betrayed them all. Thisbe struggles to regain the trust of her brother Aaron and the people of Artimé after one crucial mistake forces her to abandon her intricate plan against the Revinir. Aaron is devastated by Thisbe's actions and refuses to hear her explanation, feeling a sense of responsibility...

"Magical twins Fifer and Thisbe Stowe have spent their entire lives wishing for an adventure. When a dragon shows up claiming that his family is being kept as slaves in their homeland, the twins sneak off to the land of the dragons to help them"--

"Devastated by loss and hampered by war, Fifer struggles to regroup and continue the search for her twin. Meanwhile Thisbe, pounded by images of Grimere's dark history, contemplates her abandonment and considers leaving Rohan behind in a risky move that could take her home... or to her death--

Leaving Dev to face the Revinir alone, Thisbe leads a group to Artimé to help Fifer, Aaron, and his allies combat the reckless new head mage, Frieda Stubbs.