A thousand years ago, Princess Serafina of the ancient city of Vera fell in love with the knight Cassian. On the day the city fell, Cassian died fighting alone to cover the retreat, and Serafina was forcibly sealed in a secret passage by Drake, the Royal Guard, forever separated from him. Serafina died filled with resentment, her vengeful spirit lingering, nearly succumbing to demonic possession. To prevent her soul from dissipating, the spirit world sealed her hatred and memories, making her a "ferryman of souls"—guiding lingering spirits to let go of their obsessions and move towards reincarnation. Drake was punished by being made a guardian for a thousand years, secretly watching over them; Cassian's obsession voluntarily descended to the seventh level of the spirit world, using golden light to suppress Serafina's hatred. A thousand years later, Serafina opened the "Blackwood Agency" in Brooklyn. She rescued the dying detective Lucas, took in the psychic nurse Emily and the spiritual scholar Professor Finch, forming a team to deal with "lingering spirits." They successively helped the game developer who died suddenly, the vengeful spirit Violet trapped in the Fog Bridge, and James Chen, who had waited sixty years for a letter that hadn't been sent. With each case, Sera's sealed memories gradually awakened. She discovered that she didn't hate Cassian, but rather her own powerlessness. Drake finally confessed: Cassian had never betrayed her, but had protected her for a thousand years in the seventh layer. To find the truth and reunite with Cassian, Sera led her team to collect three tokens and venture into the seventh layer of the spirit world. She traversed the sea of memories, letting go of her thousand-year-old hatred, defeated the prison guards formed from her hatred, and finally met Cassian. The two formally parted; Cassian was reincarnated, and Sera regained her complete soul. The agency was upgraded to "The Pavilion of Rebirth - Human Office." However, a new threat descended—the Entropy Disciple Yu Nu manipulated a fragment of the Vera Jade, summoning the "Entropy Lord," who possessed Cassian's aura. A cold, golden vertical pupil opened in the void, whispering: "Serafina...you've finally remembered me."
