The scuba tanks offered limited capacity, allowing no room for delay beneath the surface. Seeing that both Ming Shu and I agreed to proceed deeper into the abyss, Irley Yang made a gesture indicating extreme caution. The three of us connected ourselves using the dive line, activated every available illumination device on our person, and descended together into the pitch-black chasm amidst the stream of white bubbles venting from our helmet valves.

We sank along the rock face. Irley Yang casually drew her dive knife and scraped away a thick layer of greyish-white sediment, revealing the surface of rough, massive stone underneath, undulating in a manner suggesting ancient stelae. I couldn't resist reaching out to trace those aged markings. Just as I prepared to continue the descent, I suddenly felt a violent tremor emanate from the rock face itself.

The moment my hand brushed against the stone wall, which felt like an undersea ruin, I sensed an abnormal vibration. A jolt of alarm shot through me; Not again, I thought, I forgot to check the almanac before this dive. Why did I have to run into an undersea earthquake? If we stayed in the trench, we could be buried alive. There was no time for hesitation now—two ducks plus one duck, we had to scramble back to the surface immediately.

I was about to signal Irley Yang and Ming Shu to retreat when I saw Irley Yang suddenly raise her square hand, making a "Be careful" gesture. I paused for a fraction of a second before realization dawned: the wall's shaking wasn't an earthquake. Something within the trench was moving. The downward current suddenly intensified. It seemed whatever was disturbing the wall was directly above us. Under such uncertain circumstances, ascending rashly was out of the question. Irley Yang guided Ming Shu and me, using the surge current to take cover behind a collapsed stone pillar on the seabed.

This trench wasn't as deep as we had imagined. Because of the complex and dark underwater currents, the terrain below was obscured when viewed from above with searchlights. However, once we descended and employed our high-intensity "Poseidon's Radiance" fluorite bulb equipment at the trench floor, the light beam revealed every detail within a radius of several tens of meters with stark clarity. The three of us crouched behind the stone, sweeping our two searchlights around, keenly observing the surroundings.

Glancing quickly under the searchlight beam, I discovered the trench was not naturally formed. The rows of rough-hewn stone pillars indicated that this was once a vast and magnificent complex of structures, submerged by some world-shattering catastrophe. The upper levels of the architecture were buried under layers of sea sand and silt, forming a brittle, hardened crust over the ages. The reason this trench was exposed wasn't due to a sunken ship, as there was no trace of any modern vessel nearby. Beside us lay only the decaying frame and keel of an ancient wooden ship, corroded beyond recognition—this was clearly a wreck from an era long past. The gap we had just descended through was most likely caused by the collapse of a few pillars near where we were hiding.

The Coral Spiral was long from east to west and narrow from north to south. The dense underwater forests were mostly concentrated on the eastern side of the depressed terrain, while the ground gradually rose to the west, where, during low tide, black phantom islands would surface. The trench we were diving in lay exactly between the coral forest and the phantom islands. During the initial reconnaissance using the diving bell, I had noticed many dark, gaping holes and ravines in the seabed around here; now I realized those might be the remains of the ancient city of Guixu, its scale astonishing.

Lost in these thoughts, I was slightly distracted when I felt Irley Yang gently nudge my left arm. The object above us also began to descend. I instinctively raised my speargun, preparing for a fight. Ming Shu shook his hands repeatedly, signaling that force was not the way to go. There must be some massive sea beast hidden in this trough, and it might not have spotted us yet. The best course was to immediately extinguish all our light sources to avoid revealing our position. Once it swam away, we could try to sneak back up quietly.

Irley Yang agreed with Ming Shu’s plan. We quickly turned off our main lights. Besides the "Poseidon's Radiance" searchlight and the clip-on headlamps we wore, our metal diving helmets each had two micro-light lamps. These micro-lights were pressure-activated, automatically turning on below thirty meters depth and impossible to switch off manually. They illuminated a range of about half a meter in front of us in the dark, high-pressure environment, also allowing nearby companions to see our faces, easing psychological stress. Compared to the powerful searchlights, these helmet lights were completely negligible; precisely because the light was so faint, leaving them on posed no risk of exposing our position.

With the light sources extinguished, the seabed plunged into absolute darkness, accompanied by a deathly silence. Thinking about the cataclysm that befell Guixu City—how everyone, man, woman, old, young, dog, chicken, cat, and poultry were likely fed to the fish—and how the local fishermen of the South Sea dared not utter the character for "pearl" when gathering oysters, supposedly because ghostly fiends guarded the oyster pearls beneath the waves—were those fiends the restless souls of the ancient city? Considering this, in the ruins of the dark seabed, a genuine chill ran down my spine. I quickly urged myself not to dwell on such morbid thoughts.

Yet, the unique deep-sea environment, combined with the pressure of over a hundred meters of water, imposed an ineffable psychological burden. An inexplicable sense of panic lingered. Knowing Irley Yang was close by helped me conquer this unsettling emotion. However, when I felt the nearby current suddenly fluctuate, realizing some large creature was passing right beside us, a fresh wave of tension seized me. I wondered if this was a common psychological manifestation of the deep sea that almost every deep-sea diver experienced. I secretly cursed myself for being useless—I could face bayonet fighting without batting an eye, but here, at the bottom of the sea, I was becoming so cowardly. I absolutely could not let Irley Yang or Ming Shu see it, or I wouldn't have the face to return to the ship.

Though I was tense, Ming Shu was even more so. He convulsed as if stung by a jellyfish, and a stream of bubbles erupted from his diving helmet. Both Irley Yang and I were startled by him, but we immediately understood what had shocked the old man. Seeing him about to pull off his helmet, I inwardly cursed that old Hong Kong farmer for having another episode, and quickly reached out to hold him down, turning his body around. In the faint light, I saw the cause: an octopus, appearing from nowhere, had tightly clamped its tentacles onto the faceplate of Ming Shu’s diving helmet. It wasn't particularly large—its body was about the size of two adult fists combined—and its skin was pale, covered in purplish-brown spots. It stared with two dull, grey eyes, wriggling them across Ming Shu's face.

Ming Shu's vision was completely blocked. Not realizing it was an octopus, he thought he had been swallowed whole by some sea beast, seeing only writhing intestines before his eyes. Despite having sailed countless ships and navigated the seas, he was instantly terrified and panicked. Fearing he might tear off his breathing tube, I quickly clamped down firmly on his hands. Irley Yang delicately used her dive knife from behind to gently pry open the octopus's arms, peeling it off Ming Shu's helmet. Her movements were so gentle that the octopus didn't perceive any threat and never shot out any ink.