The young girl Li Xiaoyu accidentally enters the world of mythical beasts in the Forbidden City because of a mysterious gem, and embarks on a fantasy growth adventure of inheritance and protection. In order to find the truth about the disappearance of the former owner of the gem, Ding Yuxing, and the clue of "a ray of light", Li Xiaoyu and "Master" Yang Yongle went back seven years ago and found that all the clues were hidden in the ever-changing Mo Naihe puzzle. In the new season, the kiss beast accidentally turned into an ordinary human being, and in the novel exploration and frequent jokes in the human world, he also started a mystery-solving journey with Li Xiaoyu and Yang Yongle. With the help of new friends such as the mythical beast seahorse and the "famous detective" little lion, everyone finally solved the mystery. When the mystery was revealed, a conspiracy that had been carefully planned for six hundred years also surfaced. The mythical beast from ancient times is about to start the trial of the human world...