Charles never thought that the copper pocket watch left by his grandmother before she died would become the key to open time and space. As a restorer of ancient books, she is accustomed to touching history in yellowed pages. However, on a rainy night, she was caught up in the French Concession in Shanghai in 1927 by the dim light of her pocket watch. At that time, the streets were filled with sycamore trees and the trams jingled. She unexpectedly met her young grandmother Shen Manqing.
