Eighteen-year-old Kayden Branimir, princess of Freca, has trained as a warrior and assassin to protect herself from her kingdom's enemies. If her foes discover Kayden's rare form of magic, they will use her as a weapon to conquer kingdoms. But when she receives a cryptic letter from her supposedly dead twin brother claiming he is in Leodia (rival territory), Kayden will do anything to escape the safety of her kingdom and find him before it is too late. Her chance to leave Freca comes as a mission: hunt down and kill the Leodian war generals. To keep her identity a secret, Kayden uses her alias Nila Stone. Nineteen-year-old Zara Tait, a Leodian spy, wants nothing more than to stand up to her queen and leave her service, but she knows she'll wind up dead if she tries. Then her dreams come true when the Leodian queen offers Zara release from her duties if she completes one last assignment: track down Nila Stone and find out her real identity. With time running out, Kayden needs to find her brother and assassinate the generals before her presence in Leodia raises suspicion. Or worse--before someone discovers her magic. Meanwhile, Zara has grown closer with Kayden. A little too close. As Zara unearths Nila's true identity, she must decide between her freedom and the girl she hadn't meant to fall for. But when the Leodian queen catches on to Zara's wavering loyalty, she threatens to kill everyone Zara loves if she fails this assignment. One choice will lead to the deaths of everyone Zara knew; one will bring destruction to entire kingdoms.