The abandoned construction site lay in the southern part of the city.
The area was overgrown with weeds, with an empty parking lot nearby and two bus stops 200 meters away.
A real estate company had contracted the land six years ago to develop a project, but when the company's capital chain broke, construction was forced to stop. The project had remained on hold ever since.
The building structure was incomplete, with exposed steel bars, giving it the look of a hazardous and decaying site.
It was raining lightly, the ground wet, mud sticking to shoes. No one came to such a place.
But today, a man stood at the gate, holding a black umbrella.
He wore a black mask, exaggerated black-rimmed glasses, and a black suit. A suitcase dangled from his hand as he walked inside.
Squelch.
Arthur stepped on broken bricks, the sound of his steps muffled by the mud. He moved with precision, carefully navigating the uneven ground.
One step.
Two steps.
Three steps.
Without turning back, he bent down and picked up a severed steel bar. From his suitcase, he pulled out a hammer.
His eyes were focused, his breathing steady, and his movements fluid. It was clear that he knew the construction site intimately—better than any ordinary engineer. He even had more expertise in destabilizing the structure than professionals.
After all, Arthur had spent thousands of hours here in the world of deduction, testing every wall, every pillar, until he discovered the three weakest points in the building's structure.
A playful glint appeared in Arthur's eyes. He picked up the steel bar like a nail and took out a tape measure from his pocket.
Squat down.
He pressed his toes against the tape measure, then stood and pulled it upwards, marking a spot at 1.62 meters.
Arthur took the small steel bar, placed it at the marked position, and raised the hammer.
Bang!
The steel bar drove into the structure.
Bang! Bang! Bang!
His hands were remarkably steady. If any old construction worker had seen him, they'd have been surprised.
A person without experience handling a hammer would often miss their target, possibly hitting their own hand instead. But Arthur's skill came from the countless times he'd practiced this exact move in the deduction system, down to the power and angle required for precision.
The next blow landed perfectly.
"Almost there," Arthur muttered to himself.
He pulled out the steel bar, then measured the depth of the depression. "12.3 centimeters."
"Two centimeters to go."
His eyes deepened as he took a breath. The final two centimeters were critical.
Too deep, and the collapse would occur too soon. Too shallow, and it might not happen at all.
Arthur swallowed, focused, and a touch of nervousness set in, even after so much practice.
Even in the world of deduction, he felt the tension each time, but the results had always been successful.
With that confidence, he lifted the hammer and continued. He knew that one person alone couldn't demolish a building, especially with such precision.
What he aimed to do was change the force distribution subtly, causing the building to collapse under its own weight. This involved extremely complex calculations of stress and load-bearing principles.
Bang!
This time, the hammer's sound was different.
Arthur quickly measured the depth again—it was exactly the same as his countless tests: 12.3 centimeters.
If he hit it again, he'd lack the strength to control the collapse properly.
He exhaled, looking down at his black suitcase. "Four seconds of full force," he whispered.
He took out his phone, opening the timer app, and watched the seconds tick by.
Next, he retrieved a power drill from the suitcase.
Only this tool could truly damage the steel structure.
Bzzzzt—
The drill buzzed, its bit spinning rapidly.
Arthur's eyes sharpened as he inserted the drill into the gap he had just created, stomping on it for extra leverage.
Tick. Tick. Tick. Tick.
Four seconds passed on the timer before he stopped.
Sweat trickled down his forehead as he strained with exertion and tension.
He paused to catch his breath before inserting the broken steel bar again, a smile forming at the corners of his mouth.
This part was key to his entire plan—a clever, artistic touch he took pride in.
Arthur then climbed to the top of the site, still holding his umbrella.
He gazed calmly at the piles of sand left behind. These piles had been transported during the initial construction phase but were abandoned before they could be used.
Two large piles of sand also sat below the building.
Some local elementary school kids used the sand piles for fun after school, jumping from above and landing on them as a cushion, playing games of bravery.
Arthur's plan was to relocate the two upper piles of sand to the unfinished side of the building, where no cement had been poured. That side was the weakest point of the entire structure.
It was tough, grueling work.
Arthur measured distances, calculating the force needed to bring the building down. The farther from the center of the support point, the greater the force he could generate with the same weight.
"Three meters."
"Three point four meters."
"Five point two meters to the left."
Arthur marked the distances, grabbed a shovel, and started moving the sand.
Wet sand was heavy, and the rain wasn't helping.
One hour passed.
Two hours.
Three hours.
Finally, after four hours, Arthur took a break. It was now 10 p.m.
Leaning against the structure, exhausted, he lit a cigarette, smiling as he looked over his work.
Both piles of sand had been moved. By tomorrow afternoon, more rain would wash away any traces of his efforts, leaving no clear evidence behind.
But a perfect accident wasn't just about causing a collapse.
The target needed to die in just the right way—by coincidence. That required meticulous planning and small actions Arthur had fine-tuned over countless deductions.
He measured more distances on the ground.
"Three inches."
"Move out—need something to cushion it."
He placed a brick to cushion the rebar, moving it to the exact position he had calculated.
Satisfied, Arthur smoked the cigarette with contentment and initiated the final test in the system.
[Start the deduction!]
In an instant, the world froze. Even the raindrops halted midair.
Time had completely stopped.
On his left was a video screen, while text commentary appeared on his right.
[Text commentary: You have officially begun the deduction!]
[Text commentary: You completed the site setup and submitted the delivery address after returning home...]
[...]
[Text commentary: Two of the three Dark Net assassins died on the spot. One was hospitalized with severe injuries and a broken leg, while Ms. Yan was hit on the head and became comatose.]
[The deduction is over!]
Arthur smiled, taking a long drag from his cigarette.
He whispered, almost playfully, "Now... let the show begin."