Millennium Love tells the epic tale of heavenly official Lu Siyuan, who commits a forbidden act to save the fairy Yuyao, incurring heaven's wrath. Condemned to an endless cycle of reincarnation, Lu Siyuan's fate becomes inextricably bound with Yuyao's across countless lifetimes. Despite their connection, a vengeful force named Xuan Qing tirelessly pursues them, determined to punish their defiance of heavenly laws. Across their multiple reincarnations, they are repeatedly drawn together, compelled to confront the profound consequences of defying heaven. While battling the relentless vengeful force of Xuan Qing, they must also protect a powerful, ancient relic. This artifact, intricately tied to their past and their original transgression, holds the key to either their ultimate salvation or the complete unraveling of destiny, forcing them to fight for their love and the very fabric of existence.