Heart of flames
(Book)

"Veronyka, Tristan, and Sev must stop the advancing empire from destroying the Phoenix Riders"--,Provided by publisher.

The world is balanced on the edge of a knife, and war is almost certain between the empire and the Phoenix Riders. Veronyka finally got her wish to join the Riders, but while she's supposed to be in training, all she really wants to do is fly out to defend the villages of Pyra from the advancing empire. Tristan has been promoted to Master Rider, but he has very different ideas about the best way to protect their people than his father, the commander. Sev has been sent to spy on the empire, but maintaining his cover may force him to fight on the wrong side of the war. And Veronyka's sister, Val, is determined to regain the empire she lost--even if it means inciting the war herself. As tensions reach a boiling point, the characters all find themselves drawn together into a fight that will shape the course of the empire--and determine the future of the Phoenix Riders. Each must decide how far they're willing to go--and what they're willing to lose in the process.