Iris, heiress of the wealthy Houghton family, suffers a brutal family massacre at the hands of Kai, her adopted brother turned ruthless mafia lord consumed by generational hatred. He imprisons her to avenge his mother’s unjust death, pushing her to suicide—yet they both reincarnate repeatedly, trapped in a four-life vicious cycle. In every rebirth, Iris struggles to save her family and flee Kai’s control, unaware he retains all past memories. His cruel vengeance hides a desperate, age-old love sprouted from a fleeting childhood glance. After endless agony, deadly fights and burning disasters, they end their cursed loop beneath Iceland’s auroras. Kai sacrifices himself to free Iris, who spends her remaining years alone, haunted by their bittersweet, tragic eternal entanglement.