This is a bond of time and space that spans a hundred years. With two ancestral silver pocket watches as keys, it connects the wonderful journey of modern young Lin Ye and "time patch" Shen Yan.
Lin Ye encounters the mysterious Shen Yan in the demolition ruins of Shanghai. He is wearing a moon-white gown and holding a bamboo bookcase. In order to make up for the regrets of the Republic of China between his great-grandfather Shen Shuyan and Su Wan, he travels through the gaps in time and space hidden in the old city. The two travel together, from the Shanghai dock in the 26th year of the Republic of China to the alleys of Nanjing covered with ginkgo trees in late autumn. They witness Su Wan escape the war and reunite with Shen Shuyan. They also help Lin Ye's grandfather fulfill his wish to send a letter, and complete the scattered family memories and cross-generational promises one by one.
However, Shen Yan's existence was originally a "patch" created by time to fill up regrets. When all regrets are fulfilled, he is destined to return to the flow of time. In the end, Shen Yan left behind the book box carrying memories, the parked pocket watch and the unfinished thoughts, and quietly disappeared into the dusk of Suzhou River.
Every late autumn, Linye still stands under the old trees in Nanjing's Ginkgo Alley, watching the golden leaves fall like fragments of time and space. The different eras that Shen Yan walked side by side with, the ticking of clocks, and the fragrance of ginkgo leaves have all become eternal memories hidden in time - some farewells require no words, while some of the companions have already been engraved into the lines of life.
