"Wait till they find out that I was never really me." So says Frey in the opening chapter of this eagerly anticipated sequel to Westerfeld's Impostors (2018). Frey, twin sister to Rafi, as well as her secret body double, is set to marry Col, a former warlord, ostensibly to bring peace to their nations. Their true plan, though, is to murder Frey and Rafi's father, a warlord in his own right. He demands that the betrothed quietly and secretly invade the city of Paz, whose people avoid problems with a happy-making app, and where the real Rafi is hiding by posing as Frey. The sisters play as each other until they can meet again, and a startling ending leaves an opening for a third entry in this futuristic techie tale. Readers of Westerfeld's Uglies series will thrill at the return to that beloved sf world, and this high-concept series, brimming with secret romance, will have wide appeal.HIGH-DEMAND BACKSTORY: Reader eager to return to the world of Westerfeld's best-selling Uglies series will be hungry for this ke sure you have Impostors, too.

Frey will do anything to find her twin sister as their father works to conquer more unsuspecting cities.After once again assuming the role of her sister, Rafi, Frey toils in her father's tower, easily fooling him and playing up the drama of her engagement to Col Palafox for the feeds. But she's a prisoner; both she and Col wear bomb collars that will explode if they attempt escape. Meanwhile, Rafi has taken on the mantle of Frey, working with rebels in the wild who are demanding their father's punishment. But their father has plans: He's set his focus on the destruction of the city of Paz, the last place Rafi was seen. But once Frey and Col set out on their mission, it becomes clear that Rafi doesn't want to be found. Even so, Frey will do anything to locate her, though she'll have to confront the fact that maybe she doesn't know her sister at all, and she certainly doesn't know herself. Propelled by intricate worldbuilding and heart-pounding action, there's never a dull moment. Frey's journey to self-discovery takes the forefront, and it's hard-won, thoughtful, and complex. Readers will jones for the next installment, eager to witness their heroine take on more thrilling adventures. As before, race is not defined in this European-inflected fantasy world. A nonbinary character has a larger presence in this book.Page-turning action made even more engrossing by a rare emotional core. (Science fiction. 12-18)