Twelve years ago, a serial murder left a mysterious "∞" symbol. Twelve years later, the same symbol appears again - this time, etched on the chest of a retired detective.
A murder occurred in the "Old Object Alley" in the old town of Linjiang City. The deceased was retired criminal policeman Lin Jianguo. The circumstances of his death were exactly the same as the unsolved "Serial Symbol Murder Case" twelve years ago. The strange symbol was also engraved on his chest - only this time, the symbol was only half-engraved.
When Chen Mo, a detective from the serious crime team, received the report, he didn't know that this would be the longest battle in his life. Twelve years ago, his sister Chen Xi was the last missing person in that old case, and she is still alive and dead. Lin Jianguo was the only person who helped him back then.
Forensic doctor Su Wan discovered a surprising detail at the scene: the incomplete symbol was stopped by the murderer on his own initiative. What does she want to convey? Warn? Signal? Or - "It's not over yet"?
As the investigation deepened, Chen Mo discovered that Lin Jianguo had been secretly investigating old cases after his retirement and left him an encrypted USB drive. The USB flash drive contains Chen Xi's last diary before his disappearance, and a name pointing to Gao Jingming, a well-known entrepreneur in Linjiang City.
On one side is the pressure from superiors, the ambiguity of colleagues, and the interruption of clues; on the other side is my sister's diary, Lin Jianguo's last wish, and the looming truth behind the incomplete symbol.
What Chen Mo didn't know was that this twelve-year chase had just begun. And each of those symbols engraved on the chest of the deceased is a path to the truth——
It is also the entrance to the abyss.
Justice may be late, but the truth is never absent.
