As soon as Lin Ye took over the ancient books department of the Municipal Library, he bumped into Shen Zhao, a criminal policeman who was investigating an old case. The ancient book restorer died in the reading area with a strange bookmark that read "Borrowing means death" pressed on his chest.
The special ink marks on the fingertips of the deceased were exactly the same as the evidence in the unsolved case three years ago. Lin Ye relied on his sensitivity to ancient book editions and discovered that the bookmark paper came from the original copy of the Republic of China that was stolen in the library; Shen Zhao deduced from the traces on the scene that the murderer was well aware of the surveillance blind spots after the library was closed.
As a second body emerges, more bookmarked "death notices" surface. Encrypted annotations in old books, strange scratches in restricted areas, and past events deliberately concealed by administrators drag the two into a conspiracy that spans several years. When clues pointed to the secrets in the unique collection of books, they were shocked to realize that they had become the murderer's "next readers".
