Lin Shen never imagined that the books Cheng Yuanyuan donated to the library concealed a secret spanning years.
A copy of Child Psychology with “In memory of Lin Shen” written on its title page, a warning scrawled between its pages: “The seventh one. Be careful.” And the words “It isn’t real,” blurred by a water stain but still faintly legible.
Seven books, seven visitors, and a warning that never reached its recipient. Following the clues hidden in the old pages, Lin Shen tries to piece together the truth, only to find that every step feels like a move on a chessboard Cheng Yuanyuan laid out long ago. What did the person who donated the books want him to find? And who exactly is “the seventh visitor”?
