An abused illegitimate daughter of a marquis is sent into a political marriage with a powerful frontier family rumored to rule a land where dragons appear and to possess the ability to control them. Behind the marriage, her father secretly orders her to discover the family’s weakness. As she lives with her cold and guarded husband, she gradually begins to see his awkward kindness and her heart starts to waver. Then, after a certain incident, she learns a dangerous secret that must never be revealed: her husband can transform into a dragon.