The Pulse Beneath the City
Late at night in the Jongro Redevelopment Area, the pulse beneath the city throbbed unseen. Yu-jin closed the car door behind her and slowly scanned the surroundings. Nothing stood out. The very fact that nothing stood out only confirmed this place was useful to someone: the long abandonment since construction halted, a blind spot in surveillance, the severed underground routes of the mutants. She turned immediately toward Ha Yul.
"Remember the signal pattern the lab mentioned? What we need to confirm today isn't simply the path the mutants have taken, but where that path actually leads. The first mutant emerged from here, and the underground movement route started here as well. So the answer that never showed up no matter how thoroughly we tore apart the surface is likely waiting below."
Ha Yul nodded. She glanced briefly at the darkness beyond the building slated for demolition, then lowered her gaze to the concrete underfoot and the temporary covers. Yu-jin signaled the two agents to follow and the four of them moved toward one side of the building. During daylight it looked like an insignificant utility entrance hidden behind safety fences and piles of equipment.
An old iron cover remained there. Its surface was thick with rust, and several bolts appeared to have been loosened then forcibly reinserted at crooked angles. To all appearances it was a long-sealed utility passage. Ha Yul crouched and pressed her hand against the edge of the cover.
"It's here," she said, then lifted it with steady power. The heavy iron plate rose, releasing the cold air trapped inside that surged upward, carrying the mingled smells of old concrete and pipe moisture. When the flashlight beam dropped downward, a worn staircase continued into the dark. Power cables and disused pipes tangled along the walls, with patches of peeled finishing material and long-dried water stains.
It was a structure that had existed before the city expanded further, with new buildings erected atop it, later deleted from maps only while the space itself remained. That was exactly what it looked like. Ha Yul descended first. Each step made the old metal staircase ring with a low clang that echoed far into the underground passage. Yu-jin followed close behind, and the two Moorim Agency agents came down with measured distance between them.
The faint city noise from above receded quickly as they descended. After several floors, only the flashlight beams and the sound of soles pressing dust remained. The underground passage was wider than expected. It was not a simple maintenance track but a scale that suggested real personnel had once moved through it, managing multiple utility rooms. Spaces erased from maps never truly disappear. Their purpose simply changes.
Ha Yul stopped at the entrance and sniffed the air. Old dust and moisture, concrete powder, the faint lingering trace of disinfectant. That last scent was recent enough to feel out of place underground. It hinted that someone was conducting work down here. Instead of explaining at length, she shot Yu-jin a look that told her to have the agent bring out the equipment.
The agent activated the portable scanner received from the lab. The data Se-a had handed over was the residual signal pattern captured from the recovered blood crystal. Se-a had judged it was most likely a trace of external connection, so today's search focused on following the extension of that signal rather than visible bloodstains or footprints.
A few seconds later, a weak response appeared on one side of the screen.
"We've got a response. It's faint, but it continues without interruption. This direction. It seems to curve along the passage rather than run straight, bending midway but never fully disappearing."
The agent's voice was calm yet tight with tension. The scanner screen jittered slightly and the values weren't perfectly steady, but they clearly held direction. Yu-jin checked the equipment once more, then lifted her gaze along that path.
"We continue. Minimize noise as much as possible. Call out the moment you spot any trace. We won't charge in relying solely on the readings. If someone is using this route, we'll meet them. We cannot hand them the first strike."
At her words the four moved again. The deeper they went, the more traces appeared. At first it was merely gaps in the dust, but after several minutes drag marks showed on the floor. They did not look like heavy objects being pulled; rather, they suggested mutants whose legs no longer worked properly or who had lost balance, brushing parts of their bodies along the ground. Recent scratches marked the walls as well. Fresh lines cut across old concrete powder, and in several places the gouges were unusually deep, as if sharp claws or nails had scraped past.
This path had clearly seen recent use. Ha Yul swept her light across the wall and spoke quietly.
"Movement traces of mutants. Some leaned against the wall, others dragged along the floor. But..." She paused and lowered the beam. "That's not all."
Yu-jin saw it too. Footprints left in the dust. Not the twisted marks of mutants, but unmistakably human. There were soles resembling work boots and lighter sneaker prints. Signs that at least one person, perhaps two or more, had regularly traveled this route. This was no accidental hiding place for mutants; it was a path used by both humans and mutants together.
Yu-jin crouched briefly to study the spacing and direction of the prints. "This suggests separate retrieval or management personnel. Either they lacked time to erase the traces or they never expected anyone to come this far."
Whether humans had led the mutants or the mutants had moved ahead could not be determined from the marks alone, but someone had transported something here and repeated the process successfully for some time. The passage narrowed, then widened again. At the end of that section the four finally faced a single metal door. It looked like a utility room entrance. Paint peeled from it, old corrosion stained the frame, and faint numbers resembling building management codes remained on the surface.
Yet as they drew closer the anomaly became obvious. There was no dust around the door. That would have been impossible for a door abandoned for years. Ha Yul grasped the handle. Beneath the cold metal she felt the unmistakable signs of use. This door had been opened and closed many times recently. She turned the handle slowly. It was not locked. The metal hinges opened with a dry rasp, and air different from the outer passage flowed out. Disinfectant and the warm scent of electronic equipment mingled thinly.
The space inside was smaller than expected. Too crude to call a proper laboratory, yet too well-equipped to be a simple hideout. Temporary power units, power strips, and forced external wiring marked the walls. Several small monitors and data terminals had been installed. A metal table stood at the center, surrounded by basic medical tools, collection instruments, sealed cases, and scattered gauze and syringe packaging that looked hastily cleared away after use. It felt like a place where someone had stripped everything to the minimum functions needed to repeat a specific task.
On the table lay several red-tinted crystal fragments and recording devices. Yu-jin spoke in a low voice.
"They made it here."
"No. This isn't where they're made. It's different from the equipment we saw in the redevelopment building," Ha Yul said after surveying the room. "This looks like a test site. A space to verify how long the signal actually lasts, whether the mutants follow the designated route properly, what happens when the response values cut off. If I had to name it... an observation post."
Yu-jin's gaze sharpened at those words. One of the agents, gloved, powered on a monitor. After several flickers an outdated interface appeared. It displayed mutant movement logs, signal strength records, and response deviations by time period. As the agent scrolled through the file list his hand suddenly stopped. Yu-jin stepped forward immediately.
The code notation. The data bundling method. The identifier attached to the filenames. She had seen this format before, in technical documents from partner companies and equipment acquisition records.
"Ga-ram Bio." Her voice dropped lower than usual. The involvement of a corporation was not surprising. Operating a facility like this required considerable funds.
At that moment the other agent, examining the file transfer logs, spoke.
"This is... strange."
Yu-jin asked at once. "What do you mean by strange? You're saying it's more than just a trace of using corporate equipment?"
The agent pointed at the screen. "It's not only that they brought and used the equipment. There are data transmission records as well. ...There are signs of bypassing, but the final destination is the internal network of Ga-ram Bio. Someone inside the company is receiving it."
Ha Yul examined the wall-mounted equipment again. Someone was moving mutants beneath the city and sending the data to the corporation. Yet the site used makeshift setups instead of expensive gear, the records were precise while the recording space itself was crude. It meant someone was using the corporate system while operating outside the company's official facilities.
"It's still too early to conclude the corporation is behind this," Ha Yul said quietly. "We have traces of corporate equipment and traces flowing to the corporation, but nothing that reveals who is directing it. On the contrary, it's too obviously left behind. As if someone is deliberately making it look like the corporation's work."
Yu-jin gave a slight nod of agreement. "Exactly. That's what makes it more troublesome. We must determine whether the corporation is leading this or if there's a mastermind manipulating the company from behind."
At that same moment the information reached Ga-ram Bio as well. Ga-ram stood in her private office on the upper floors of the company laboratory. The emergency report from the Jongro Redevelopment Area was simple: estimated location of blood crystal entity test site discovered, underground observation space secured, data transmission record confirmed, final destination Ga-ram Bio internal network. The report's format was dry, but its contents were anything but.
Ga-ram remained silent for several seconds. The employee before her felt oppressive weight even though it was not directed at him; he kept his mouth firmly shut and waited.
"Have I ever approved this? Re-examine the project, budget allocation, external sample collection, everything. Check whether anything connected to this exists among the items I approved or delegated."
The employee shook his head at once. "Nothing has gone through your approval line, CEO. Within the range we've confirmed it does not match any official project code, and the internal network access rights exceed those of a standard partner account. Someone among the executive staff is using internal company privileges."
Ga-ram slowly leaned back in her chair. Someone was collecting blood crystal data without her approval, in a form connected to tests that moved mutants beneath the city. If an external force had stolen internal rights, it was a security breach. If an insider was operating independently, it was far more serious. It would mean the true owner of this company was not Ga-ram but someone else.
"How interesting." A smile hovered where interest and displeasure clung together across a thin membrane. Ga-ram tapped the report once with her fingertip and added, "It seems we have someone inside our company. And quite a bold one, to deceive me. Good. At least now we know more clearly what we must look for, don't we?"
She issued several more instructions at once. Do not launch a formal audit. Disguise the copying of internal server access records as an external security inspection and proceed quietly. Separately gather every internal account that accessed Jongro-related keywords and all records of nighttime network bypasses. And deliberately refrain from a full blockade so they could see who would panic and move first. Ga-ram knew well that when the opponent was hiding, waiting yielded far more information than squeezing them dry.
Two shadows existed beneath the city. One was the corporate shadow that sought to control mutation. At least on the surface, Ga-ram Bio spoke of management and control, application and regulation. The other was the shadow of someone who was deceiving even that corporation, borrowing its name or gnawing at its interior while continuing quieter, more persistent experiments in the urban underground. Whether this was internal rebellion, external erosion, or both remained unknown. What was certain was that the true depth of the Jongro Redevelopment Area incident far exceeded anyone's imagination.
Seoul continued to turn with its lights blazing, and people lived their usual lives above ground. Yet beneath it all, along invisible veins, something pulsed and flowed.