Oathbound — Donna Maree Hanson

We have some time before the Ancient Evil can reach into Argenterra. We are not the Ungiven Land yet…Sophy lies trapped within Rufus's jewelled prison. Protected by her oathbond to Oakheart Rufus cannot touch her, but her crystal form is draining Argenterra of the given. Oakheart has to leave Sophy behind because he is bound by his promise to return Gillcress to Princess Aria at Valley Keep.The weakening of the given has repercussions: oaths are fading and darkness has festered in Prince Dellbright's heart. Oakheart fears for Aria and Gillcress, but he must return to the Lower Warrens and free Sophy -- and before the jewel she is trapped within drains the given completely from the land. Accompanied by an adept and the forest folk, he sets out to rescue her. The order from Crystal Mountain Retreat is, if Sophy cannot be freed, she must be destroyed…