Rumor has it that there is a fairy mountain on the sea, named Penglai, where immortals can refine elixirs and obtain immortality. However, thousands of years have passed and no one has ever actually seen or found Penglai. Later generations only thought it was just a myth. There are guests coming from the sea, and the place they come from is Penglai.
It was five hundred years ago when Yu Dong came back to the world. At that time, it was still the Qing Dynasty. Men wore pigtails and women bound their feet. She stayed in the world for two hundred years, experiencing the late Ming and early Qing Dynasties. Until she was tired of the quarrels in the world, she returned to Penglai and slept for more than two hundred years.
When she woke up again, it was the sea that woke her up. There was a lot of resentment in the sea. The sea couldn't bear it anymore so it woke her up and asked her to go to the human world to find out the origin of the resentment and eliminate it. All things in the world have spirits, and Yu Dong is the entruster. When all things are in need, they will entrust her with help. But she was too weak to wake her up easily. Now for some reason, resentment flowed into the sea, and the creatures in the sea were overwhelmed, so the sea woke her up.
As soon as Yu Dong woke up, the world was changing rapidly and earth-shaking changes occurred. Yu Dong observed various languages and living customs of human beings through the water mirror for several days. Unable to bear the urging of the sea, Yu Dong hurriedly left for the human world.