Forest of Firelight by Shari L. Tapscott

Enter the world of The Riven Kingdoms.

After the sudden death of her brother, Princess Amalia is charged with what feels like an impossible task—she must choose the next king. Youthful thoughts of love are pushed aside as she accepts her fate, setting upon a quest throughout the kingdom to find a man worthy of her father’s throne.
Little does Amalia know, someone has already set his sights on her.
Rhys is a man of secrets, and his mission is simple: befriend the princess of Renove. Coax her to trust him, convince her to follow him.
Betray her when it’s time.
All goes according to plan until Rhys meets the princess. Amalia is a disaster. Never has he met someone so drawn to trouble. Never has he met someone so irritatingly likable.
He’s not allowed to fall for her.
She could never entrust him with a crown.
But, unbeknownst to them, their unlikely partnership might be the key to saving their entire world from a darkness that’s slowly creeping from the wounded earth that separates one kingdom from the next.