After the heroine Su Wan experienced a "resurrection from the dead" in a bizarre car accident, she discovered that her eyes could see "abnormal residues" that ordinary people could not detect - traces of the murder scene that had been processed, strange obsessions wrapped around objects, and even "death echoes" floating behind the body. As a result, she was recruited by the mysterious department "Seventh Bureau" and became a non-staff "observer". Together with her cold and powerful partner Shen Ye, she dealt with the emerging bizarre incidents involving supernatural forces. In the process of solving cases such as "Ghost Subway Passengers", "The Curse of Internet Celebrity Live Broadcast Room", and "Village with Collective Amnesia", Su Wan's abilities continue to evolve, and the price gradually becomes apparent. She discovers that she is related to the source of these "abnormalities" - a global "limbo tide" that was covered up. Shen Ye's true identity, the purpose behind his silent guardianship, and the truth about Su Wan's own car accident constitute the ultimate suspense that runs through the book and is nested layer by layer.
