Only months after her victory over Oberon and Titania, everything Lydia thought she'd accomplished is unraveling: Faerie is falling into decay, the Fae are restless, and Taylor—the baby sister she sacrificed everything for—has grown up without her.When Taylor tumbles out of the ordinary world and into Faerie, she discovers that Aeon, her imaginary childhood friend, is all too real. He is a powerful Fae, trapped in a maze of vengeance, memory, and madness. His unleashed power threatens to free Oberon and Titania and reignite the war Lydia ended.The sisters, now nearly strangers to one another, must figure out how to keep Aeon from destroying Faerie while safeguarding the mortal world, all without sacrificing the Fae who was once friend to them both.