Chapter 20: Where Does It Lead? |
The sharp ring of the phone shattered the silence of the study.
Shen Mo pressed the answer key. The voice of the city bureau's criminal investigation squad leader came through, tinged with a suppressed urgency.
In the past three months, there had been five cases of falling from a height. The deceased were unrelated, the only commonality being that they all died in the stairwells of old-style company dormitories.
More precisely, they died on the "thirteenth step" counting from the top.
The results of the on-site investigation were almost bizarre: no signs of a struggle, and the shoe prints of the deceased showed no deviation, as if they were just walking downstairs normally but fell out of thin air.
The autopsy reports pointed to an even more puzzling detail. At the moment of the fall, the muscles of all the deceased were in a state of extreme relaxation, as if they had not realized the danger was coming at all.
These buildings where the incidents occurred were all built in the 1980s and belonged to the same batch of "South City Housing Project."
Shen Mo's fingertips swiped across the tablet, pulling up the case files.
The most crucial piece of information jumped out: all the staircases involved used treads supplied by the same building materials factory.
The survey data next to the photos showed that the standard height of each step should be 17 centimeters, but at every crime scene, the measured height of the thirteenth step was generally lower, averaging only 14.3 centimeters.
However, on the original architectural drawings, all the data was precise, with no record of any construction errors.
A tiny structural difference, five lives. This was no coincidence.
Shen Mo drove to one of the dormitory buildings where the incident occurred, which had not yet been unsealed.
The old corridor was filled with a damp, musty smell. The voice-activated lights flickered dimly.
He avoided all the residents and, at two in the morning, the time when he was least likely to be disturbed, he stood alone in front of the staircase that led to death.
He took out a portable laser rangefinder and a high-precision humidity sensor from his investigation kit, fixed them on the wall opposite the thirteenth step, and began continuous monitoring.
Time passed, minute by minute. The corridor was dead silent.
Three hours later, when the reading on the hygrometer slowly climbed to 85%, a sudden change occurred.
On the screen of the laser rangefinder, the reading representing the position of the step's surface began to fluctuate slightly.
Shen Mo's pupils contracted. He saw that after the wooden tread had absorbed enough moisture, its surface showed a faint swelling, imperceptible to the naked eye.
But that was not the key.
The key was that, at almost the same moment, a supporting structure beneath the step underwent an instantaneous deformation that lasted only 0.8 seconds.
In that 0.8 seconds, the thirteenth step suddenly sank a full 13 centimeters.
A perfect "misstep trap."
When a person walks down the stairs at a normal rhythm, their foot expects to land on a solid step but instead steps into a deep hole that appears out of thin air.
The huge height difference is enough to make a person lose their balance instantly. Before the brain can even react, the body has already fallen backward in a completely relaxed state, the back of the head hitting the hard concrete steps below.
Shen Mo put on gloves, took out a special sampling knife, and carefully scraped some wood shavings from the side of the step.
Under the high magnification of a portable microscope, some extremely fine metal powders, shining with a dull luster, were clearly visible in the gaps of the wood fibers.
He immediately performed a rapid component analysis. The result made his heart sink.
Technetium-99, that rare man-made radioactive element, was identical to the residue he had previously detected on the mysterious cufflink and the ancient stone tablet.
The clue, once again, pointed to the huge mystery hidden in the city's shadows.
That night, a letter with no name and no postmark appeared silently in the crack of his apartment door.
The envelope was sealed with a long-obsolete bone glue and exuded a faint fishy smell.
The letter paper was ancient-style bamboo fiber paper, its texture coarse and tough.
There were no words in the letter, only a severely yellowed black-and-white photograph.
In the photo, three men in old-style work clothes were moving wooden planks in a dim warehouse. On the mottled wall behind them, someone had scrawled five words in thick charcoal: "The thirteenth step leads to the abyss."
Shen Mo turned the photo over. On the back was another line of elegant but forceful handwritten small characters: "They didn't finish the walk, so the stairs won't stop either."
He immediately called Su Wanying, briefly explained the situation, and asked her to use her authority to help find the archives of the building materials company related to the "South City Housing Project" from the 1980s.
The next morning, Su Wanying's call came, her voice tinged with gravity. "I found one, a wood processing factory called 'Hongyuan Wood Structure.' It specialized in providing prefabricated staircase components for the housing project, but it went bankrupt in 1985. As for 'the abyss'... I asked a few retired old construction workers. That was the nickname the workers privately gave to the factory's 'thirteenth-step inspection platform' back then."
Shen Mo rushed to the city archives without stopping.
In a dusty construction log, he found the key record.
"Hongyuan Wood Structure" had undertaken the staircase projects for all the buildings where the incidents occurred in 1983. The log clearly stated that the fir wood used was precisely the "M8313" batch that had been severely dampened due to a warehouse leak.
A thought stirred in his mind. He then applied to check the death records of that year.
On October 7, 1983, on the acceptance day of the first batch of installed staircases, three inspection workers fell from a height and died while testing the stairs.
The official conclusion was "accidental misstep after drinking," and the families received no compensation.
Three workers. The ones in the photo were them.
At the end of the death record, there was another name—Chen Jianguo, the fourth worker in the same group. He was the sole survivor, having suffered partial memory loss due to a severe concussion.
Based on the information in the file, Shen Mo found him in a nursing home in a distant suburb.
The old man was no longer as robust as he used to be. He just sat blankly in a wheelchair, clutching a crayon, repeatedly drawing a distorted "13" symbol on a white piece of paper, muttering indistinctly, "The step... sank... sank... We shouted, no one listened... no one listened..."
That night, Shen Mo and Su Wanying, following an old map, found the original site of "Hongyuan Wood Structure."
It had long since become an abandoned auto repair shop, the air thick with the lingering smell of engine oil and rust.
In the depths of the factory's underground warehouse, they found a forgotten, un-dismantled section of an old staircase.
That was the "abyss" of yesteryear—the thirteen-step inspection platform.
The thirteenth tread was already rotten and broken, teetering on the verge of collapse.
Su Wanying took out a wet cloth from her backpack and carefully wiped the underside of the rotten wooden board.
As the dirt was wiped away, three long-blurred fingerprints and half a line of almost illegible charcoal writing stubbornly appeared: "We are here... remember us."
Shen Mo's gaze sharpened.
He took out a matchbox-sized stress sensor and gently attached it to the wooden board's support structure.
Just as he was about to connect the data cable, the device's screen suddenly lit up, emitting a sharp alarm.
Without any external load, the rotten step had sunk a full 13 centimeters on its own, paused in the air for 0.8 seconds, and then silently returned to its original position.
Su Wanying covered her mouth in astonishment.
But Shen Mo stared intently at the data curve on the screen, which had plummeted and then instantly rebounded. His voice was low and hoarse. "It's not a malfunction... it's a memory. This memory, soaked in despair and anger, has been permanently recorded by the Technetium-99 and this damp wood. It's replaying."
As soon as his voice fell, the concrete ceiling above them began to seep water droplets without any warning. One drop, two drops... gathering into a stream, dripping onto the ground at their feet.
The sound was crisp and rhythmic, as if right above their heads, an invisible person in heavy boots was slowly walking down from a height, step by step.
Exactly thirteen sounds.
The sound disappeared, and the underground warehouse returned to a dead silence.
But a greater storm was raging in Shen Mo's mind.
That sound was not a hallucination, but the echo of some kind of energy.
He suddenly remembered the paper in the nursing home, the one Chen Jianguo had filled with "13"s.
The old man had not just drawn the number. Next to each "13," there seemed to be an extremely sloppy symbol that he had overlooked.
And in that dusty construction log, in the record for October 7, 1983, besides the official conclusion, in the blank margin of the page, there also seemed to be a meaningless mark drawn in pencil.
Those two symbols, which he had dismissed as unconscious doodles, now, in his mind, began to slowly overlap.
(End of Chapter)