On the mysterious Rokkenjima island, Shannon serves the enigmatic head of the Ushiromiya family, Kinzou. Despite knowing the impossibility of it, she harbors feelings for George, Kinzou's grandson. When the Millennial Witch, Beatrice, offers to help Shannon and George's forbidden love by breaking a ritual mirror, Shannon's world shifts. As their relationship blossoms, Kanon, another servant, grapples with his own emotions and unexpected affection from Jessica, Kinzou's granddaughter. Amidst the annual family gathering and a treasure hunt orchestrated by Beatrice, the fragile bonds of love are tested as dark secrets and hidden motives unravel. In a deadly game for power and legacy, the servants must navigate treacherous waters to shield their beloved ones amidst the looming threat of tragedy.