Yun Heng was a loose cultivator in ancient times. He once committed a major sin against the Immortal Sect and was exiled for thousands of years. His soul was left in the mortal world. However, the boundaries between immortals and mortals are gradually lost, spiritual energy is turbid, and gods wither. Yunheng lives in the market, hiding in the hustle and bustle of the city, selling calligraphy for a living. The world is chasing profit, and all old friends have faded away. Only he uses a piece of broken talisman to watch the final clear day of heaven and earth. However, fate is unpredictable. One night of nightmare, evil spirits appear in the world, and ancient decrees descend from the sky, ordering him to reorganize the immortal way and save the world. Yun Heng originally had no intention of embarking on the path to immortality, but an orphan girl in the mortal world aroused a wish that had been unfulfilled for a hundred years in his heart. Should we choose to be independent from the world and let the world destroy itself, or should we rekindle the glimmer of immortality in the ruined world of mortals? When cultivating immortality is no longer about ascension, but about protection - Yun Heng writes a legend that is both ancient and new among the urban fireworks.