Shiguang Pavilion, deep in the rain alley, repairs antiques openly but collects obsessions secretly. Shopkeeper Lin Yanqiu guards the shop passed down by his grandfather. The old watch on his left wrist always turns upside down when it touches an object "stained with thoughts", as if to warn of something.
One rainy night, the man in black left behind only a hollow brass lock. Dark red oozed under the rust of the lock body, and there was a sob hidden in the hole, as if someone was sealed in copper. In order to repair the lock, Lin Yanqiu found the broken wall of Gu's house in the Republic of China, dug out the old news about "the disappearance of the Gu family" in the archives fragments, and took over half a jade pendant from the mysterious old lady - when it was put together with his mother's belongings, the inscription "Gu gave to Lin" in the gap revealed the deep connection between the two families.
Grandfather said, "You have to pick up lost time and lock it." But when the pieces of the brass lock were put together, he was shocked to realize: the hollow core was never a lock, but a key. On a rainy night in the 23rd year of the Republic of China, the murder of the Gu family contains the secrets of three generations of the Lin family; the words "An" and "Ning" engraved on the lock are the names of two people, and they are also a cycle of obsession that spans a hundred years.
The old watch turned over more and more quickly, and the drawer of the Shiguang Pavilion opened by itself. In the old photos that surfaced this time, the face of the cheongsam woman was finally clear—it overlapped half of Lin Yanqiu's appearance in the mirror.
