When she was young, Karenzia lost her parents and was taken in as an adopted daughter by the Count Giese family, where she endured years of mistreatment. One day, Karenzia is sent to marry an elderly duke in place of her stepsister. However, at the secluded mountain estate where the duke supposedly resides, she instead encounters a melancholic young man. To her shock, a dagger is lodged in his abdomen! The duke, cursed with immortality, pleads with Karenzia—the only one who can see the sword—to remove it for him. Yet, he warns her that pulling the sword will end his life. To protect the newfound place she’s finally come to call home, Karenzia proposes a contract marriage to him, but...