Holding a lantern whose fuel was nearly exhausted, Ding Sitian strained to read the faint markings left on the cement slab in the dim, bean-sized light: "Water Supply Unit? 3916? What does that mean? Is this a military installation?"

Fatty and I heard her and squatted down to examine the cement. This flat slab of concrete looked deliberately made to seal a vertical shaft, but it hadn't mortared the opening shut; it could be easily opened with a crowbar. Both sides of the slab bore markings—some sort of standardized building material.

Since the Qin Dynasty, there had been regulations requiring artisans to engrave their names on bricks and tiles for supervisory management, but this cement slab looked nothing like an antique. What was a "Water Supply Unit"? Was it military? Is 3916 a unit designation? I wondered if some army had excavated the cave in the center of the tunnel filled with ghost-suppressing stones. I looked at Fatty and Ding Sitian; they were equally puzzled, unable to decipher its purpose.

I told them, "Forget the numbers on this cement for now. The secrets hidden in the Hundred-Eyed Cave are too numerous. Even if the three of us grew an extra head each, six heads combined couldn't figure these things out. Since we can't understand them, let's not waste our energy worrying. This forest is fraught with danger, and running into venomous creatures like centipedes again would be troublesome. But the terrain is complex and hard to navigate, and without our mounts, plus having to carry Old Sheepskin, it's impossible to feel our way out in the dark tonight. We must first find a relatively safe place to wait until dawn before making further plans."

Ding Sitian looked up at the star-dimmed sky, saying to me with deep worry, "I feel like tonight is passing so slowly and dragging on. We don't even have a watch to tell the time, and we don't know what hour it is; how much longer until daybreak?" As she spoke, she extinguished the lantern. A faint starlight filtered through the woods; she intended to save the last bit of lamp oil for emergencies.

I looked up at the sky too. Though the starlight was meager, fortunately, I could still vaguely make out the main stars. I first found the handle of the Big Dipper to confirm our direction. Then I located the Three Stars, which hung horizontally, faintly gleaming, slanted toward the east. In the Northeast region at night, time was calculated by the position of the Three Stars in the sky. By my estimation, it was only around ten o'clock at night. The desolate wilderness darkened early; it had been six or seven hours since sunset, but midnight had not yet arrived.

Fatty also knew how to tell time by the Three Stars. He calculated with his fingers and determined there were at least seven more hours until dawn. Where could they possibly find safety for such a long time? He suggested they return to that earthen pit they were in earlier and just rough it out until morning before finding a way to leave.

But the three of them instantly recalled the hordes of wild rats in the hole, the filthy, damp environment, the large stones used to suppress ghosts, the constant threat of collapse, and the vividly sinister mural of the "Yellow Immortal Auntie." They immediately dismissed the idea. Seeing an old tree nearby growing thick and tall, I decided to climb it to survey the surrounding terrain before making a final decision.

Reaching the base of the tree, I used all four limbs, scrambling up the trunk to the crown. By then, the mist in the woods had dispersed. I stood on a branch, hugging the top of the tree, and looked down. I could no longer clearly see the faces of Ding Sitian and Fatty. I waved to them, ignoring whether they saw it or not, and looked up to survey the surroundings.

But then, dark clouds obscured the moon, leaving only a few cold stars visible. After looking for a long time, I could only see the hazy shadows of nearby trees; I couldn't make out any place to shelter. In the dim darkness, one instinctively tries to open their eyes wider, wanting to see more clearly, but even after straining until my eyes ached, I saw nothing.

Hugging the trunk, I rubbed my eyes with one hand and twisted my neck to look in another direction. Just then, the high clouds drifted, and a chilling, watery moonlight shone through a thin patch. In that moment of hazy moonlight, I discovered that behind me, separated by only a few trees, stood a vague shadow—it looked like a large complex of buildings. Because all the structures were lifeless and dark, they appeared only as a pitch-black silhouette resembling architectural facilities.

When I tried to focus my gaze again, the drifting clouds had once more covered the moon, and the area further away was pitch black; I couldn't even make out a shadowy outline. Given the cement slab with the unit number I found earlier, I wasn't too surprised to spot some buildings nearby, but I truly hadn't expected Zhang Ran to be this close to us.

I considered waiting for the moonlight to leak through again to get a clearer view, but Fatty and Ding Sitian below were worried I might slip and fall, urging me to come down quickly. So I swiftly slid down the tree and explained what I saw in the canopy to Fatty and the others. There seemed to be structures resembling houses over there, but they were dark and silent. If they were indeed buildings, even if abandoned, they should at least have four walls and a roof, and perhaps we could find some food inside, which would be better than freezing and staying in the dark woods. Thus, the three of us unanimously agreed to wait there until daylight.

I pointed out the direction, and the three of us slowly carried Old Sheepskin toward it. As we walked, I noticed someone following behind us, but when I looked back, there was nothing moving. I thought I had misheard and didn't pay much mind, leading them through the knee-deep wild grass in the woods. Ahead of us stood a three-story building.

The exterior of the building was ordinary but possessed an air of foreignness, neither distinctly Western nor Chinese in style. The windows had glass and were remarkably intact; it was clearly a modern structure. Fatty leaned against a window, peering inside for a long time. There was no light whatsoever; nothing could be seen, except that all the window seams were sealed with strips of paper bearing strange Japanese characters and symbols.

Ding Sitian said to me, "This building isn't like a Western villa or a modern Chinese building. In my impression, only the Japanese people would construct buildings in such an odd style. The Soviet revisionists certainly couldn't have built here. Perhaps this was the barracks for that Water Supply Unit?" This area was under Japanese control during the War of Resistance, making it highly likely to be a barracks-type structure. At that time, the Japanese, imitating Europe, were extremely Westernized, believing everything European was superior; even ordinary housing would incorporate some features of Western architecture. If that were the case, this place should have been abandoned for at least twenty years now.

I nodded without speaking, thinking that this area had been occupied by the Japanese devils. Were the bandits of the 'Ni'er Hui' collaborators? Did they offer up whatever they dug up as tribute to the little devils? I wondered what secret this building might hold, but these were just speculations. It was best to wait until morning to figure things out. I called to Fatty to carry Old Sheepskin, and we walked along the base of the wall until we found the entrance.

The building before us looked no different from an ordinary old residential block, only three stories high. From the outside, each floor appeared to have about twenty windows, all tightly shut. The interior was eerily quiet. Fatty remarked, "This place is good. We get in, close the door, and nothing can get in. We can just stay until morning."

We all knew that the centipedes active nearby had the habit of "hiding by day and moving towards scent by night." If we waited until daylight to head out of the woods, we wouldn't have to worry about them. Seeing the building was solid and intact, we felt it was a perfect place to hide. The door wasn't locked, merely ajar. It was a set of double doors, each with a small square glass window, but there was no sign on the door itself.

To bolster everyone's courage, I kicked the door open. Since it hadn't been opened or closed for many years, the hinges were nearly rusted shut, letting out a harsh, grinding sound. Unused for ages, the interior was coated in dust, with cobwebs hanging in the corners. The air wasn't fresh; it carried a faint smell of mold. While it was also a place where gloom had settled for years, it was much better than the damp, fishy stench of the earthen pit.

Fatty and I slung Old Sheepskin's arms over our shoulders and stepped into the corridor. It was too dark inside. Though she hated wasting kerosene, Ding Sitian had to light the lantern for illumination. Walking, we observed the layout of the structure. Inside the main entrance, there was a large mirror that blocked off more than half of the once-wide passageway. In front of the mirror was an iron grate. The grate was not lowered, and its operating lever was on the outside; there was no switch inside, meaning it could only be opened from the exterior, much like a prison. The mechanism of the grate appeared to be air-valve operated, meaning it could function without electricity. Such a device indicated that this building was once a highly secure, confidential facility. The interior walls were whitewashed, and the floor was cement, but the only strange thing was that every internal door was bricked up, except for the corridor itself. There were no rooms with entrances.

The three of us were greatly perplexed. Isn't a building constructed for habitation? From the outside, this building was unremarkable, so why were all the interior doors blocked with bricks? We reached the stairwell and found the stairs had not been blocked with bricks. It seemed the only preserved spaces inside were the hallway and the stairs. The external windows were merely for show.

We couldn't help but stop at the stairwell, unable to proceed further. The fact that this building wasn't a building was utterly bizarre. We even doubted if the Japanese had built it as a barracks. Who would go to the trouble of building a tower with no rooms? It was clearly just a useless block of concrete.

Ding Sitian suddenly said, "That's right, Comrade Lenin, I remember you and Fatty saying that where you did your manual labor, there was a custom. Placing stones in a house can... suppress... suppress ghosts? If every room in this building is filled with bricks, could it be...?"

Fatty and I deliberately mimicked Ding Sitian's hesitant rhythm, replying, "You... you... look how scared you are, you're stuttering. Those are superstitious customs from the Four Olds; how can you take them seriously? Besides, burying stones in a house is to allow people to live in it peacefully. Every room in this building is tightly sealed with bricks; forget people living here, even a thief couldn't get in. Do people live in the hallway? Who sets stones to suppress ghosts like this? It would be easier to just demolish the building."

Ding Sitian said, "Don't mimic me. I'm genuinely worried. Maybe this building shouldn't even be demolished; tearing it down might cause bigger trouble. They had to fill the rooms with bricks..."

I thought Ding Sitian's imagination was running wild. I needed to give her a prophylactic shot. Otherwise, with such a superstitious state of mind, she wouldn't make it through the night. So, I casually pulled out my Little Red Book and said to her, "We advance fearlessly following the Great Red Sun. If any class enemy tries to rise from the dead, we will criticize and denounce them until they are thoroughly discredited."

Fatty interjected, "That's right! Not only criticize and denounce them, but stomp them under a thousand feet so they never rise again... But, to be fair, I also think there's something seriously wrong with this building. It’s built like a concrete coffin."

When I heard even Fatty was unnerved, I realized this building was truly abnormal. Who knew what it was used for? Truthfully, I was getting spooked too, but a person couldn't lose their composure when their framework was shaking; I needed to find a way out for myself. So, gripping the Little Red Book, I said, "Although we are completely unafraid of the arrogant posturing of the imperialists and revisionists, this place has no ventilation whatsoever, all the entrances are blocked, the space is cramped and oppressive—it’s no different from that tunnel full of thieves. I think it’s best if we spend the night outside the main door."

My companions immediately agreed. No one wanted to linger in this concrete block that resembled a sarcophagus. We immediately turned back the way we came and reached the double doors. Seeing the two small windows on the door, I finally realized that perhaps only the windows on the main door were real. Looking from the outside in was pitch black, and looking out from the inside through the glass was equally dark and unclear.

As I reached out to push the door, I heard a "Bang! Bang! Bang!" knocking sound coming from outside the door. The knocking wasn't very loud, but in the silence of the dark building at night, it was extraordinarily startling. I flinched, and the hand that had reached out to push the door retracted. The Hundred-Eyed Cave was rarely visited, and the four of us were together—who could be knocking outside?

However, my subconscious told me this thought was fundamentally wrong. That double door wasn't locked at all; it would open with a light push. If someone wanted to enter, they wouldn't need to knock—unless it wasn't human? Thinking of this, sweat beaded on my forehead. It seemed some things simply had to be believed, regardless of one's will. I involuntarily stepped back a few paces.

The three of us exchanged glances, none daring to make a sound. The knocking outside stopped for a moment, as if waiting for a response. Then, "Bang! Bang! Bang!" three more times, each knock closer than the last, seemingly intended to deliberately torture our already taut nerves. Fatty was also frightened to the core, but given his nature, he gathered his courage, opening his mouth to shout toward the door, "Who is it? Stop knocking, damn it! Nobody's home!"

The sound outside immediately ceased. We strained our ears inside, listening intently to the sounds outside the door. At that moment, even the air seemed to freeze. It was so quiet you could probably hear a strand of hair drop to the floor. But this silence lasted less than three seconds before the "Bang! Bang! Bang!" of heavy striking returned.

My mind jumped. I suddenly recalled an experience on night watch at the lumberyard where a spirit knocked on the door late at night. But that time, it was probably caused by a weasel. Thinking of this instantly dispelled my fear. Blood rushed to my head, and I drew the "Kangxi Treasure Saber," walked to the door, and prepared to kick it open. I was determined to see what the hell was causing this haunting.