Downstairs, to avoid frightening the couple—Hoa Ngoc Anh and Thai Tieu—Da Dang Ha intentionally withheld information, keeping them in the dark about the object the police were searching for. Instead, he told the couple that the police were looking for a murder weapon hidden by the killer 100 meters away from the crime scene.
Suddenly, Phan Thap Hoa rushed downstairs in a panic to report. His voice stammered after witnessing a horrific sight he would likely never forget:
"Inspector Da! Found... It's been found!"
Immediately afterward, the box was brought to the police station for investigation.
The victim's head had not yet entered the decomposition stage, so it remained intact. The blood on a section of the victim's neck had been wiped clean, covered by two layers of plastic food wrap, with a bottom liner meticulously placed to ensure no blood leaked out.
According to the forensic experts, there were clear bruises caused by impact during transport. Along with them were several faint marks, likely left by the killer's fingers. The diagnosis pointed to a middle-aged man with calloused fingers, aged between 35 and 45.
During the investigation of people in the surrounding area, from 3:00 PM to 4:00 PM, the rural roads were deserted; only eight people had gone out. None of them were suspicious, nor had they entered the couple's house or carried a cardboard box on the road.
Da Dang Ha hypothesized: it was very likely the killer did not transport the box directly but concealed it using another means of transportation.
With this information, Da Dang Ha began to cordone off the area surrounding the crime scene, starting with Ke Tuyen district, followed by Thanh Tuyen.
There were a total of 53 people in the commune between the ages of 35 and 45. Among them, seven were acquaintances of Hoa Ngoc Anh and Thai Tieu, and three had relationships with both Doan Kieu and the couple.
All the clues quickly helped Da Dang Ha narrow down the scope of the search, but a lingering doubt remained in his heart. He wasn't sure what it was, but as a man who worked by logic rather than intuition, he quickly brushed it aside and returned to the case.
Only three suspects remained. Tonight, he would temporarily detain them for interrogation.
At 23:58, as the minute hand neared the 12 on the clock, the telephone suddenly rang at the Gia Uyen Provincial Police Station while Da Dang Ha was busy interrogating the three suspects. A female officer picked up the phone and said:
"Hello, Gia Uyen Provincial Police Department for Crime Investigation and Prevention speaking."
On the other end, the low voice of a middle-aged man rang out just like before. However, in contrast to his previous composure, the female officer was now terrified, her hands trembling as she held the receiver. On the other end, the voice said deliberately:
"Near Bach Giang, at the moment where day and night intertwine, the angel shall fall asleep in an iron box, and her smile will sink into the white mist of sin."
As soon as the words were spoken, the line went dead, leaving a trail of terror behind. Remembering the gruesome words from a few days ago, the female officer turned pale and rushed to find Da Dang Ha, who had just finished the interrogation. She said:
"Inspector! Him! The killer just sent a message!"
Upon hearing "killer" and "message," he looked in astonishment at the three suspects who had just been interrogated and were preparing to leave under the escort of three officers.
That killer was definitely not in Ke Tuyen district, but in Thanh Tuyen—the hometown of the recently slaughtered victim.
But this time, the killer had increased the difficulty of the game. He no longer announced a specific time, giving only a timeframe: "the moment where day and night intertwine." But which day would the crime occur?
"White mist," "Bach Giang"? Although Bach Giang (Thach Ha district) was a river known for its fog, during this season—especially at the "moment where day and night intertwine"—there were no days with fog on the Bach Giang.
Or had the killer made a mistake?
Impossible. This killer meticulously mapped out his plans before every crime; he couldn't make such a foolish error.
He looked up at the clock; it was already 2:00 AM. More than two hours had passed since he began contemplating the next crime scene.
Did "white mist" simply mean fog?
As the dim light flickered on the crowded highway in Gia Uyen, a black car sped down the road, overtaking rows of other vehicles.
Screech! The car quickly pulled up in front of the Gia Uyen Provincial Crime Prevention Police Station.
A 23-year-old man stepped out of the car. He had short, bright yellow hair, wore gold-rimmed glasses, sucked on a lollipop, and was dressed in a black T-shirt and long black pants, with a bright yellow jacket over the top.
He was Lang Dinh—despite his youth, he was one of the top cyber investigators in Nam Duong.
With his hands in his pockets, he walked inside with a leisurely posture, treating the public office as if it were his own home.
The door opened. When Da Dang Ha saw Lang Dinh, he was somewhat surprised; he hadn't expected this arrogant man to agree to his request so easily.
Recalling two hours ago, while still sitting in a daze over the case, Da Dang Ha had thought long and hard and decided to invite Lang Dinh to join the investigation.
.....
At that time, he had called Lang Dinh hoping for help, but the attitude on the other end of the line was quite indifferent, as if he didn't care about the case at all.
"Is it that killer's case? He's just a psychopath who likes to show off. Just let him kill one more person and he'll show his true colors."
Da Dang Ha sighed worriedly and said:
"But I feel he isn't like the typical killers we usually catch. Moreover, Gia Uyen is usually a place where crime is scarce; now that this cold-blooded killer has emerged, it will surely cause a shock throughout the province."
Lang Dinh sat in his room, listening to the phone while spinning his chair, and said:
"Is that all? Fine. If he causes such a stir, those 'little rats' won't dare to run wild either."
Lang Dinh fell silent for a moment, thinking, then smiled and said:
"As for the cooperation, let's see what kind of mood I'm in first."
...
Seeing Da Dang Ha's worried expression, a flicker of amusement appeared on Lang Dinh's face. He walked over and held out a hand in a common social greeting:
"Hello, Inspector Da. I am Lang Dinh, here to lend you a hand."
Putting aside the reflections on their previous conversation, Da Dang Ha immediately brought out a recording of the call and evidence suggesting the culprit might be from Thanh Tuyen district.
Lang Dinh glanced over the summary, especially the killer's second challenge. "Angel"?
Da Dang Ha rubbed his temples and said:
"Perhaps the previous victim was killed by him accidentally and it had nothing to do with 'justice' like he claimed. If even you can't solve this, I'll have to ask that guy..."
"No need!"
Lang Dinh interrupted Da Dang Ha immediately. In Lang Dinh's eyes, that mysterious person was the wall he had to overcome.
"As a policeman, don't keep relying on a psychology kid like him!"
Lang Dinh knew well that the mysterious individual would never refuse any case, because his sole purpose was to bring the darkness into the light.
Although he never revealed his identity and could only be spoken to through regular phone calls, as long as he personally intervened, that case was extremely serious, and the culprit would certainly face the death penalty.