Officer Sun told me this case dated back exactly ten years. Back then, he was just a captain in the criminal investigation team—his rise owed much to my grandfather's help.
My grandfather had a strange temper and rarely intervened, but when he did, he always cracked the case.
It was a starless night. He was delivering some documents to a local police station when a middle-aged man staggered in, clutching a plastic bag. His face was flushed, like a drunkard's. Upon entering, he shouted that someone was trying to kill him—then collapsed to the floor.
Sun initially thought it was just a drunk, but checking his breath revealed he was already dead.
Opening the plastic bag, they found a human heart inside.
The victim showed no wounds and appeared as if asleep, with no signs of abuse or poisoning. His car was parked outside the station, the engine still warm, and only his fingerprints were found inside. In other words, he had driven himself to report a case—and died there.
The victim was identified as a judge in the city.
The department took the case seriously, dispatching the best detectives and forensic experts to form a special task force. But after days of investigation, no clues emerged—not even the cause of death.
The team was full of experts, but arguments broke out frequently. Everyone was unwilling to yield, each pursuing their own lines of inquiry. The investigation was chaotic, lacking leadership.
Sun was the least influential member of the group. When he suggested calling my grandfather out of retirement, the experts laughed him off, mocking that it would be better to summon a Taoist priest than a washed-up coroner.
Then the second case happened. The victim was a female wealthy entrepreneur who had returned from overseas.
Like the first victim, police found a heavy plastic bag near her corpse—inside was her own heart.
The investigation stalled completely. Desperate, Sun brought the files to my grandfather, who agreed to help. But when they arrived at the forensic department, the bodies had already been dissected.
The autopsy was brutal—only one fact stood out: the hearts in the bags were the victims' own, removed without damaging the body surface.
My grandfather immediately said he couldn't handle the case, because of a strict condition he imposed on the police—no one was allowed to touch the bodies before he took over.
Sun begged hard and convinced him to stay. My grandfather insisted on visiting the second victim's home.
The house had been searched multiple times. Apart from footprints and fingerprints left by the police, there was nothing. The killer's hallmark was cleanliness.
Motive, method, evidence—all too clean. No clue was left behind.
Yet, my grandfather was no ordinary man. He drew the curtains, then ignited bundles of mugwort smoldering in the dim room—a traditional wuzuo ritual to reveal hidden traces. Slowly, eight crimson characters seeped through the plaster like fresh blood:
"River North's Severed Blade, Punish Evil, Promote Good."
This was likely the killer's self-given title. The phrase "Punish Evil, Promote Good" meant to eliminate wickedness and uphold virtue for the common people.
Sun hurried back to the station and pulled up the victims' records. The judge had taken bribes and framed a pair of righteous men as murderers; the female entrepreneur had inflated cancer drug prices, exploiting patients for profit.
The killer judged them guilty, self-proclaiming 'righteous punishment.'
Then came the third murder. The victim was a university professor, notorious for his immoral behavior—he had exploited his female research students and even used videos to blackmail them.
He died during an academic conference, in front of many journalists.
The media blew the story up. Online, some people started to idolize this 'people's avenger,' accusing the police of mixing good and evil. The task force faced huge public pressure.
Yes, society had many injustices and many villains who exploited loopholes. But law and order must prevail. No one had the right to wield such terror in the name of justice.
My grandfather demanded an immediate autopsy. Despite opposition, Sun allowed him into the morgue alone.
My grandfather locked himself inside for a full day and night. Sun guarded outside, allowing no interruptions.
Once, while Sun was away, a trainee forensic doctor accidentally opened the door and saw a shocking sight: my grandfather and the corpse both wearing ritual masks—a wuzuo ritual to commune with the dead. He had suspended the body with ropes, reenacting the crime scene.
After that long day, my grandfather burst out laughing.
Sun asked what he had found.
He admitted the case defeated him. He couldn't solve the mystery of how the hearts were extracted alive.
But he did gain some insight.
"The corpse told me: the killer is 1.8 meters tall, slim build, triangular eyes, blade-sharp brows, high nose bridge."
Sun trusted my grandfather's expertise. He immediately mobilized all available police forces to conduct a carpet search of H City for anyone matching this description.
Though they didn't find the killer, they found a key witness.
His name was Zhang Bao, a former gang member who had served three years for killing someone. He claimed to have seen a man matching that description lurking near his home. Fearful for his life, he requested police protection.
My grandfather reviewed Zhang Bao's testimony, then compared it with the three case files.
He marked several strange symbols on the map of H City and ordered Sun to search the designated streets immediately.
When asked how he deduced the locations, my grandfather only urged haste.
The police knocked door to door. Sure enough, a landlord reported renting to a man who looked exactly like the description.
The landlord showed a rental contract signed in a distinctive left-slanting script.
Sun was ecstatic. He dispatched two officers to retrieve the contract, while the others searched the suspect's residence.
Inside, they found numerous clippings—photos of the three victims and Zhang Bao, whose face was slashed by a dagger, all pinned to the wall.
This was enough to confirm the tenant as the infamous River North's Severed Blade.