In this fantastical tale of demonic battles and courtly intrigue, the onmyoji known as the 'Heretic' faces a destiny that could forever change both human and demon realms! The emperor commands Fuzuki to look into the unsettling disappearances of young women near Mount Goun. With Hakuro sidelined by injuries, Fuzuki heads off with Ranmaru in tow to investigate the area where the kidnappings occurred. They're directed to a supposedly abandoned manor deep in the mountains, where they come face-to-face with a deadly demon impervious to Fuzuki's onmyoji arts. Can the Heretic survive a fight he seems doomed to lose from the start?