Synopsis: The Holy Grail of Eris

House Grail defies the typical behavior of nobles who resort to deceit, manipulation, and extortion to gain power. They steadfastly adhere to the principles of truth and integrity, and even the youngest daughter, Constance Grail, upholds these values by striving to do what is right and help those in need. However, these principles offer no comfort to Constance when she learns of her fiancé's infidelity with another woman. Adding insult to injury, his lover falsely accuses Constance of wrongdoing, and she finds herself alone in her defense—except for the ghost of Scarlet Castiel, seeking revenge for her wrongful execution ten years earlier. Scarlet possesses Constance and implores her to help avenge those who wronged her, despite not knowing who framed her. Although Constance wants to stand by her principles, the cost of her assistance may be too high.