Under Chang'an City, there is an underground river that only exists in "Shui Jing Zhu".
Legend has it that whenever the moon reaches its peak, the boatman will appear amidst the sound of bells and drums and take you to see a city that does not belong to this era.
Shen Guiyi was originally an ordinary restorer of ancient books in Guitu, until one day, when she was repairing "Ch'ang'an Chronicle", she was attracted by a line of small cinnabar characters that she had never seen before.
At night, she was attracted by the sound of bells and saw a "dry well" with water and a sudden appearance of boats and punters. When she came to her senses, she saw the majestic Suzaku Gate above her head. Walking beside her were monks from the Northern Wei Dynasty with wide robes and long sleeves, vendors from the Northern Song Dynasty selling "Bingxue Leng Yuanzi", and a strange woman holding an oil-paper umbrella who claimed to be from Ba County in the Republic of China.
And the man standing on the tower, dressed in mysterious clothes, looking at her quietly, was the defender of this lost city.
He guarded this city for a thousand years, just waiting for someone who could repair the mountains and rivers.
"Miss Shen," he called Shen Guiyi, his voice like snow falling on the bell and drum towers, "this city is sick, just like the mountains and rivers."
"And the book in your hand is Yao Yin."
