The Midsummer Captives Firethorn Chronicles, Book 2.

A sorcerer's fortress. A lost heir. A determined princess. Gwen, second of the twelve princesses of Ituria, has given up on happy endings. After a neighboring kingdom's heir stole her heart and then disappeared four years ago, she buried her heartache and vowed to serve her sisters. Her most recent mission: to arrange a match with her sister Hazel and the lost heir's youngest brother. When her traveling party is ambushed, her flight from danger l...