Atwater-Rhodes (In the Forests of the Night) takes a break from vampires to create two warring clans: avians, who are human and bird, and serpiente, who are human and snake. No one remembers how the conflict began, but narrator Danica Shardae, the beautiful but tough avian leader, is tired of the bloodshed that has killed most of her family. She longs to end the war, enough to agree to choose serpiente leader Zane Cobriana as her mate, even though she has always "feared" and "hated" him. Not everyone is on board with this plan; members of both clans are critical, and both Danica and Zane have love interests among their own kind whom they must now abandon. Plus, there's a mysterious assassin among them. While the writing often comes off as overwrought, Atwater-Rhodes creates impressively complex cultures for both the avian and serpiente people. She gives each clan a mythology, distinctive fighting styles and different ways of relating to one another. Avians, for example, are known for their reserve, while the serpiente are passionate people who would never expect their leader to "choose his mate for politics." The trajectory is fairly obvious, but readers are still likely to be caught up in the details of the avian Hawk's Keep and the serpiente palace—and to wonder who is out to destroy the "fragile peace." Ages 12-up. (July)