In the 25th year of the Republic of China, strange things happened frequently in the Shanghai concession: missing people left strange symbols, and echoes of owners came from the alleys late at night. Behind seemingly unrelated cases, there were secrets that spanned ten years. Su Qingyuan, a private detective who believes that "existence is absurd", does not pursue the truth, but only seeks "why the incident happened." Carrying an old copper ruler and a notebook, she wandered through the bizarre world of Shili Foreign Market, dealing with pretentious policemen, secretive businessmen, and crazy witnesses. Every time a mystery is solved, there is another layer of doubt about "existence" - why do people insist on the truth? Why can obsession control life and death? When she approached the core secret, she realized that she had already been trapped in the whirlpool of absurdity, and the so-called "truth" was just another carefully designed nothingness. There is coldness hidden in the humor, and philosophy wrapped in suspense. Let's see how she finds the meaning of existence in the fog.
