In the quiet town of Birch, Thorne has always believed herself ordinary—a wingless thumbling and baker’s assistant with no place beyond her small, contained life. That illusion shatters the night she unknowingly unleashes forbidden essentia in the presence of General Pox, marking her as something dangerous. Taken to the castle of Vaelvar to be executed for wielding outlawed essentia, she is saved at the last moment by Crown Prince Ashriel, who believes she may be the key to something far greater. But escape does not mean safety. As Thorne is hunted, traded, and imprisoned by those who sense the power within her, it becomes clear she is more valuable—and more dangerous—than anyone anticipated. As the being who hunts her closes in, Thorne must decide whether to become the weapon others seek, or risk unleashing a force known only as Oblivion.