In early April, the annual "Yunzhou Go Master Invitational Tournament" kicked off at the city's Cultural Arts Center, attracting top players from all over the country. The tournament not only garnered attention from the Go community but also drew interest from corporate executives and investors, as the sponsor behind it was the rapidly rising tech company, "Wanchuan Intelligence."
However, just as the tournament entered its second round, a sudden death occurred.
At the player's table, a man dressed in a dark Zhongshan suit suddenly clutched his chest while making a move, his face turning pale. His body swayed and collapsed onto the chessboard. People around him panicked, and by the time emergency responders arrived, his heartbeat had stopped.
The deceased was Feng Qishan, a five-dan Go player, 36 years old. He was introverted but known for his aggressive playing style, making him a rising star in the Go community in recent years.
The police immediately sealed off the scene, and Su Wanqing, as a forensic consultant, was urgently called in to assist with the investigation.
After an initial inspection of the body, Su Wanqing noticed that Feng Qishan's lips were slightly cyanotic, and his fingertips were twitching slightly. These signs indicated that the cause of death was likely acute neurotoxin poisoning.
"There are no obvious injection points, no external wounds," she frowned and said, "The toxin most likely entered his body through his mouth or skin mucous membranes."
The only objects he had consistently touched at the scene were the chessboard and the pieces.
After extracting samples from the items at the scene, the forensic team quickly detected botulinum toxin derivatives on several black pieces. This was an extremely difficult-to-detect and potent poison that could cause heart and lung failure within a short time.
"The toxin was only found on the few black pieces he had handled, and these pieces were distributed only at today's tournament," Su Wanqing analyzed. "This indicates that the toxin was introduced at the scene and was targeted specifically at him."
Lu Chenzhou quickly retrieved surveillance footage and traced the scene, recreating a timeline of the event. While each player's pieces were distributed by the referee at the beginning of the tournament, he noticed that before the match began, Feng Qishan had briefly talked with a player at the neighboring table, and there had been an instance where he mistakenly picked up the wrong chess set.
That player was Lin Yuwen, 27 years old, a local Go Association's promising young talent. He had a refined appearance and a steady playing style. It was noteworthy that Lin Yuwen was the tournament favorite, and Feng Qishan had just been randomly drawn as his opponent the day before.
Su Wanqing and Lu Chenzhou, with doubts in mind, went to Lin Yuwen's residence for a routine inquiry. However, they found Lin Yuwen alone in his study, visibly nervous, with his fingers nervously rubbing a Go piece.
When questioned by the police, Lin Yuwen initially stammered and claimed that he was "unaware" of anything, saying he had only "discussed some game strategies with Feng Qishan." However, when Su Wanqing presented the toxin detection report, his face changed drastically, and he nearly broke down.
"I didn't kill him…" Lin Yuwen whispered repeatedly. "But he threatened me. If I didn't withdraw from the competition, he would release a video."
The police traced the source of the video, discovering that Feng Qishan had secretly recorded footage before the match—during an internal training game, Lin Yuwen had used a tiny wireless earphone and received remote assistance to "make moves." If this cheating behavior were made public, it would ruin his career.
"Feng Qishan was an honest man," Lin Yuwen mumbled, his head lowered. "He said he couldn't tolerate such things in the professional Go community… But it was just one mistake…"
After reviewing the evidence, the police confirmed that Feng Qishan had indeed submitted a tip-off to the tournament committee through an anonymous email just a few days before, including the video, but due to insufficient evidence, the tip-off was still in the "review" stage.
As the investigation reached a standstill, an important lead came from a tournament volunteer. She recalled that before the match started, Lin Yuwen had asked to "borrow the restroom" but had lingered outside the referee equipment room for several minutes. That room was where the chess sets were temporarily stored, and only staff members had the key.
"If he had obtained the key beforehand, he could have tampered with Feng Qishan's chess set when no one was looking," Lu Chenzhou said calmly. "The key point is—who helped him open the door?"
The police quickly followed the lead and discovered a staff member, Zhu Min, who was a high school classmate of Lin Yuwen. She had previously assisted him in the Go club. Surveillance footage showed her leaving her post briefly, during which time the chess set was swapped.
Zhu Min eventually admitted that Lin Yuwen had confided in her, saying "someone was threatening him" and asked her to help him "secretly change a few pieces," claiming it was part of a "psychological strategy to confuse his opponent."
"I thought he was just being clever… I never imagined it would lead to a death…" Zhu Min wept with regret.
At this point, the truth behind the case was revealed. Lin Yuwen was formally arrested on charges of intentional poisoning resulting in death. Although he repeatedly claimed that "killing was not his intention," the design of the deadly chess pieces and the precise use of the toxin proved that this was not a spur-of-the-moment decision, but a premeditated plan.
Standing in the empty chess hall, looking at the chessboard that had been taken away, Su Wanqing couldn't help but sigh softly, "One wrong move, and the whole game is lost."
Lu Chenzhou looked at her and said, "Some people, unable to afford to lose a single game, want to cheat to win their entire life."
Beyond the chessboard, there was a far more ruthless game being played.