Working overtime late at night, Shen Jinwan received an ancient book without words.
A line of red words appeared on the cover: When you return home after midnight, if the lights are three long and two short, take seven steps back and close your eyes for thirty seconds.
She did as she was told and saw blood stains on her original position.
The ancient book says: You have become a recorder. There is a "night watchman" on each floor of this building. The little girl on the fourth floor has been dead for twenty-five years, the actor on the sixth floor never opens the door, and the bloody hand on the fifth floor lives next door to you.
Shen Jinwan thought they were the most dangerous ones.
Until a new rule emerges from the ancient books: Don't trust anyone, including yourself.