Jeongsan Reservoir: Master of the Abyss

Three months ago, the disappearance of renowned marine biologist Dr. Han Ji-hoon briefly but intensely captured media attention. He vanished without a trace during a deep-sea survey in Jeongsan Reservoir, an artificial lake in the deep mountains of Gangwon Province, infamous for its abyssal depths. Official reports concluded it was a drowning due to equipment malfunction, but local residents whispered a different story. Then, two weeks ago, an anonymous post appeared on a domestic occult forum. It was a 12-second clip from Dr. Han's recovered ROV footage. The damaged, noise-filled video showed a colossal, ambiguous shadow passing directly beneath the drone, followed by violent disturbance, and then the screen froze. Crucially, in a single frame just before the freeze, an enormous form with black scales of immense size was captured. A giant body, easily 20 meters long, was coiling at an unnatural speed. The clip was dismissed as an elaborate CGI fabrication, yet the footage persistently haunted me. It eerily aligned with chilling local legends about 'Jiriyeon,' an ancient, gigantic river Serpent said to inhabit the deepest parts of Jeongsan Reservoir.

Driven by professional curiosity and a growing unease from the video, I packed specialized acoustic and sonar equipment, along with high-definition underwater cameras, and set out. Jeongsan Reservoir was located in a forgotten, remote part of Korea, a five-hour drive along winding, unpaved roads. As I neared my destination, the air grew heavy and damp, and the silence became oppressive. The reservoir itself was vast, its surface reflecting the ominous, cloudy sky like polished obsidian. There were no bird calls, no insect hum. The only sound was the distant, rhythmic lapping of water against unseen rocks. Near an old, abandoned fishing pier, where Dr. Han's boat was last seen, I found a rusted buoy, its ropes neatly severed, left adrift. The water at the edge of the pier was strangely calm, yet my handheld sonar immediately detected an anomalous, fluctuating depth far below. It was as if the lakebed itself was subtly writhing.

I lowered my modified unmanned submersible into the depths. A few meters down, the water temperature plummeted, becoming icy cold. Above, in my small rubber boat, I felt a subtle drift against the wind caused by a minute current. The silence deepened further, as if even the distant lapping sounds had been swallowed. A subtle, constant pressure change was noticeable in my eardrums, similar to ascending a mountain, but the pressure was going down. The drone's sonar began to fluctuate erratically. Ghostly, colossal forms flashed across the screen. They were far larger than any known fish, yet too fluid to be geological structures. I readjusted and re-checked, but the readings persisted. Then, my directional underwater microphone picked up something chilling: a deep, low vibration resonating from below. Not a natural hum, but a rhythmic thrumming, like a living drumbeat from the Earth's core, subtly vibrating the hull of my boat. The drone's light, piercing the absolute darkness of the abyss, occasionally illuminated massive, indistinct objects, but they vanished before identification. These were not rocks, nor debris, but incredibly vast, curved surfaces.

As the drone operated at 150 meters, a sudden, violent sonar signal erupted. A colossal serpent-like form was directly ahead, then circling. The thrumming vibration intensified, becoming physically painful, bone-rattling. My small boat was abruptly rocked by an unseen force. Not waves, but a deep, violent disturbance directly beneath me. The water around the boat violently swirled, forming impossible small eddies against the natural flow. I struggled against the powerful currents, attempting to retrieve the drone, when suddenly the world tilted sideways. A vast, dark mass, gleaming and slick, surged above the water right next to my boat. Not an animalistic jump, but a controlled, almost deliberate movement. It was impossibly huge. A section of its body, thick as an ancient tree trunk and covered in scales the size of dinner plates, rose silently, incredibly high, then arced back into the water at a terrifying speed. It didn't directly strike my boat but re-submerged with a colossal, mountain-collapsing roar in the distance. The displacement of water instantly capsized my small boat, throwing me into the freezing, churning water. Disoriented, gasping, I felt a horrifying, overwhelming suction from below at my leg—an immense, primal force trying to drag me down. I thrashed and screamed, my fingers scrabbling against the mossy underside of my overturned boat. At that moment, a massive, black eye, gleaming like obsidian, slowly emerged from the abyss. It was impossibly large, devoid of emotion, yet filled with a terrifying, ancient intelligence. It moved not with malicious intent to attack, but with a cold, indifferent efficiency, asserting its domain.

I don't remember how I escaped. Only a desperate crawl to the surface through suffocating pressure, excruciating cold, and lungs bursting with pain. I washed ashore, half-drowned and bruised all over. My left leg screamed with excruciating pain, as if it had suffered hundreds of internal ruptures. All my equipment was gone, swallowed by the reservoir. I crawled, gasping, barely making it back to my car. When I finally got a signal, the authorities, as expected, listened to my disjointed, panicked story with skepticism. They attributed it to hypothermia, shock, and collision with underwater debris. I was told to be thankful I didn't end up like Dr. Han.

I never went back to Jeongsan Reservoir. I never will. But sometimes, when I'm alone in my quiet office, the phantom pain throbs in my leg, and I feel a subtle, resonant vibration deep in my chest. A deep, low thrumming that seems to emanate from impossible depths. And when I look at the medical scans of my fractured tibia and crushed muscles, the doctors still cannot explain the perfectly circular, incredibly deep imprints found on the bone. They dismiss them as odd impact marks. I know. They are the pressure points of a serpent's constriction, a silent, ancient bind, and physical evidence of the terror lurking beneath the calm. And sometimes, in the dead of night, I can almost hear the soft, rhythmic lapping of water against unseen rocks. It promises no peace, only the endless watch of the abyss.