Born as an illegitimate daughter of a marquis, Astrid grows up abused and treated as nothing more than a disposable pawn. One day she is sent off in a political marriage to the Valrick family, rulers of a remote frontier where dragons appear—and rumored to possess the power to command those dragons. Behind the scenes, however, her father gives her a secret order: “Find the Valricks’ weakness and use it.” As she begins her new life with her wary, emotionally distant husband Cassian, Astrid gradually glimpses the clumsy kindness beneath his cold exterior, and her heart starts to waver. Then, due to an unexpected incident, she discovers a truth that must never be revealed to anyone: Cassian himself can transform into a dragon. Knowing both his secret and her own role as a “sacrificial pawn,” Astrid must choose what to protect—her father’s schemes, or the husband she is coming to love.