Sherwood Smith 
Sartor 

In this sequel to The Spy Princess, Lilah, newly made a princess, teams up with Atan, the hidden princess of the oldest country in the world, Sartor, to free the kingdom from a century of enchantment. Capture, escape, a forest beyond time, ancient beings, civilizations secreted in caves, and a deadly enemy await the girls. Atan knows that if she survives, the challenges facing a fifteen-year-old queen are only beginning.