Attending ex-girlfriend's wedding, arresting the groom's officer on the spot

Standing at the company entrance, Zhang Hui gazed at the bustling street, a sense of disappointment creeping into his heart. A seemingly crucial lead had been abruptly cut short. But he knew that in criminal investigation, every setback was a new beginning, and he and his team had to pick themselves up and find the next breakthrough.

Wang Shuai sat at his desk, the ashtray overflowing with cigarette butts, the cold light from the computer screen reflecting on his weary face. Days of investigations had yielded no results. Frustrated, he scratched his head, his gaze inadvertently sweeping over Li Pengcheng's social media accounts. Among hundreds of posts, a six-month-old post suddenly caught his attention: a picture of a group of people carrying mountaineering gear standing at the foot of a snow-capped mountain, captioned, "Conquered another peak with my 'Deep Mountain Explorers' partners!"

He immediately zoomed in on the image, carefully examining each person's face, and then searched through Li Pengcheng's other related posts. Finally, he found the group icon for "Deep Mountain Explorers" in the comments section. Following this lead, he contacted the cyber police and obtained the group's detailed information through technical means. When the list of twenty-seven members appeared on the screen, Wang Shuai's pupils contracted slightly, as if he had seen a glimmer of hope.

He printed out the list overnight, circling each name heavily in red pen, as if trying to etch them into his heart. At dawn, he rushed into the meeting room with this list, a culmination of countless hours of hard work, slamming it down on the table with a crisp sound. The twenty-seven names stood out sharply in the morning light, like a code waiting to be deciphered, or a signpost guiding the way. Wang Shuai rubbed his bloodshot eyes, his fighting spirit rekindled, and issued commands into the walkie-talkie, thus beginning a tense investigation.

Our first stop was team leader Zhou Ming's outdoor gear shop. Climbing ropes and waterproof jackets were displayed in the glass window, and the walls were covered with photos of the team members on their adventures, with Li Pengcheng standing in the middle, beaming. Zhou Ming paused, wiping the shelves. "Pengcheng is the life of the party in our team. He always helps the girls carry their bags when we go into the mountains." He opened a drawer and pulled out an activity logbook. "Our most recent group activity was about two weeks ago, on the Yunling Ancient Trail. After that, everyone arranged their own itineraries."

When Wang Shuai pulled up the surveillance footage showing Li Pengcheng entering Luoying Valley alone, Zhou Ming's face turned deathly pale: "Luoying Valley is not on our exploration route at all! The terrain there is complex and landslides are common. We have strictly prohibited our team members from going there on their own." He trembled as he found the WeChat group chat history, where the group announcement clearly stated in red: "Entering Luoying Valley is strictly prohibited."

The investigation team split up, searching for clues in every corner of the city. Team member Xiao Chen arrived at programmer Wu Hao's rented apartment, where unfinished code still lingered on the computer screen. "I was writing code at home on the day of the incident; the company's backend has my login records," Wu Hao explained, pulling up a work document with the creation time accurate to the minute. He opened his phone's photo album, filled with videos of his cats he had filmed indoors; the sunset outside the window seemed completely out of sync with the time of Li Pengcheng's murder.

In fitness instructor Lin Yue's studio, Wang Shuai looked at the class schedule she showed him. "There are private training sessions all day on the 23rd, members can testify." She pulled out a surveillance video, showing her instructing a client on strength training, her sweat-soaked sports vest clearly visible in the footage. When asked if she knew about Li Pengcheng's secret investigation, Lin Yue shook her head: "He only said he was preparing a 'big surprise,' but didn't reveal the details."

The most challenging case was that of freelance photographer Chen Yan. His camera bag always contained climbing ropes and a first-aid kit, and his computer was filled with stunning photos of snow-capped mountains and canyons. "I was indeed in the mountains that day, but not in Luoying Valley," he said. He pulled up his camera's GPS track, which showed that he was in Cangyan Mountain, a hundred kilometers away, at the time of the incident. However, Wang Shuai discovered a deliberately hidden video on his memory card—the image was shaky and blurry, with several people arguing in front of the mine shaft, and the background sound was drowned out by a sharp electrical noise.

"What's going on?" Wang Shuai froze the frame. Chen Yan's expression changed drastically: "I accidentally filmed this last week while shooting footage in an abandoned mine. I thought it was just a regular dispute and didn't make a fuss about it." After the technical department processed the noise reduction, the words "Sea Sand. Report" could be heard intermittently in the video, which cheered everyone up.

However, a deeper investigation revealed that the video was taken a week before Li Pengcheng's murder, and the parties involved were in a dispute with a local construction company, which had nothing to do with Li Pengcheng. Meanwhile, other team members reported back: Zhang Wei, a senior executive at a company, was in a meeting, and the entire meeting was documented; Zhao Yu, a college student, was studying in the library, and surveillance cameras captured her entering and leaving; and retired teacher Lao Zhou was practicing Tai Chi in the park, which could be corroborated by elderly people doing morning exercises.

As the alibi of the last member was verified, Wang Shuai stared at the names being crossed off one by one on the whiteboard, a wave of frustration washing over him. Twenty-seven meticulously prepared investigation plans had yielded twenty-seven dead ends. He opened Li Pengcheng's notebook again, filled with detailed notes on outdoor equipment reviews. On the edge of the last page, a string of numbers, "17234," was written in pencil, next to which was a drawing of a rusty pickaxe.

Technician Yang Sen stared at the string of numbers, pondering them repeatedly: "It's not a password, not coordinates, and certainly not a phone number." When he entered the numbers into the scenic area's management system, a long-forgotten record popped up on the page—on February 3, 2017, a landslide occurred in Luoying Valley, trapping four explorers, one of whom was carrying the rescue equipment donated by Li Pengcheng.

“Perhaps this isn’t a number, but a date,” Wang Shuai suddenly said. They immediately pulled up the news report from that year. In the yellowed photos, a young Li Pengcheng stood in the rescue team, his volunteer badge gleaming. The report ended by mentioning that the accident was caused by illegal mining that damaged the mountain structure, and the mine involved was the source of the red soil that Yang Sen had detected on site—Hongda Mining.

Night fell once more over the Criminal Investigation Division. Wang Shuai slammed the files on Hongda Mining onto the table. The photo of Song Jun, the mine owner, gradually overlapped with the outline of the sketch in Li Pengcheng's notebook. The rusty pickaxe seemed to pierce through the fog, pointing to the heart of the case.

The conference room was filled with smoke. Wang Shuai slammed a thick stack of documents onto the conference table, the four large characters "Hongda Mining" on the cover standing out prominently. "Take a look, everyone. We've unearthed quite a bit about Hongda Mining these past few days, but the situation is far more complicated than we imagined." His voice was hoarse from staying up all night.

The team members gathered around, their eyes fixed on the densely packed documents. The data showed that Hongda Mining owned multiple mines near Luoying Valley, and over the past decade, it had been repeatedly warned and penalized by relevant departments for illegal mining and safety accidents. (End of Chapter)