My physical condition is the worst among the people here. I really shouldn’t be moving at all, and my third uncle knows this, yet he still asked me to go down. Clearly, he wouldn’t have me doing any heavy labor; I believe he has his reasons. However, the smell from the drainage ditch makes me not want to go down at all.

But there’s no way out; everyone is looking at me, both curious about what’s below and aware that the guy in dark glasses has left me no room to refuse. I have no choice but to let him guide me as I descend through the crack.

Perhaps it’s a psychological factor that intensified my illusion, but as soon as I got down, I immediately smelled a strong odor of urine, so intense that it made it hard for me to breathe. Moreover, this channel wasn’t as easy to navigate as I had imagined; the angle was very steep. Watching my third uncle descend so smoothly, I realized he must have been using all his strength. I slipped a little, and immediately a lot of filthy mud mixed with urine and moss stuck to me. I couldn’t help but frown.

The guy in dark glasses above laughed and said, “Sorry, buddy, but urine is good for the skin.”

“Damn it, it’s a good thing you didn’t let them crap down here,” I cursed.

He chuckled, and the people above, hearing this, thought something had happened. The rope paused for a moment, and he quickly signaled for them to continue lowering it.

Soon, everything around me was pitch black. It was so narrow that I couldn’t even lift my head. Besides the flashlight from the guy in dark glasses, I couldn’t see anything. Fortunately, I was going down; climbing back up would have been even more exhausting.

I looked at him still wearing his dark glasses and couldn’t help but ask, “Can you see with those things on?”

He smiled at me and said, “It’s clearer with them on than off.”

I didn’t understand what he meant, but since he didn’t want to explain, I didn’t ask further.

As we continued down, we quickly reached the opening of the sandy crack I had seen earlier. Shining the light in, I immediately discovered a hidden world inside. It was a gap that could only fit one person at a time, with their chest pressed against the back of the person behind them. Once inside, I realized that although the gap was very narrow, it was extremely deep, with developments both above and below. It looked as if a massive mountain had been split in half, and I felt like I was crawling into a knife’s edge.

What surprised me was that the walls of the gap were lined with small niches resembling Buddhist shrines found in caves. Each niche was a depression carved out of the sandy wall, and every one of them contained a clump of dry mud, stuck in place with filthy mud and intertwined with the surrounding roots. The mud was cracked, resembling dried soap.

Looking around, I saw these depressions everywhere. Wherever the flashlight illuminated the deeper parts of the gap, there were more of them.

We squeezed into the gap, and I touched the sandy soil inside, finding it as hard as stone. This must be the sedimentary soil of the sand, very damp and rich in moisture. As I pushed deeper inside, I suddenly found myself next to the edge of a mud cocoon. I wanted to touch it, but the guy in dark glasses shouted at me not to, saying, “Be careful, don’t touch those mud cocoons.”

“What’s inside these cocoons?” I asked.

“Dead bodies.” He shone the light on one of them, which was a cracked clay cocoon. Inside, white bones were exposed. “This is a flexed burial; this might be the most primitive well shaft built by the ancestors at the time. There are no stones, just some mud-filled cracks in the mountain, which were later used as burial sites.”

“A burial site? In a place like this?” I was puzzled.

“Building such a project would have certainly caused many deaths. These might be slaves captured from other countries who died here. It’s impossible to transport them out for burial, so they were buried on the spot. There are quite a few near the Great Wall,” said the man with the black glasses. “We’ve arrived.”

I looked down; the crack didn’t reach the bottom, but on one side of the crack, the stone wall continued to split, revealing a gap with flashlight beams flashing. Clearly, my third uncle was inside.

The man with the black glasses signaled upwards, and the rope stopped. We carefully climbed down, and my third uncle reached out to pull me inside.

This crack was extremely narrow and, most critically, very low, barely half a person’s height. I had to crouch to get in. My feet were in agony, and as soon as I entered, I collapsed on the ground. Soon after, the man with the black glasses also crouched in.

Looking around, I found that both sides of the crack were filled with tiny tree roots and mud cocooned in dry mud, arranged in a depression on either side, with the sound of flowing water echoing from beneath the ruins. Looking further in, I realized this crack connected to another stone well shaft. Clearly, the earthquake had caused the sandy soil layer to crack, linking two well shafts that were quite far apart; we had taken a shortcut.

Inside the well shaft, it was a mess, with cracks everywhere. It was evident that when the ruins collapsed, countless such cracks were formed.

I asked my third uncle, “Why did you want me to come down?”

“I wanted to show you something,” he said, motioning for me to follow him. We crouched and moved a few steps in the low crack, and he pointed his flashlight at the sandy wall behind a tree root.

At first, I couldn’t see what was there because the tree roots were all stuck to the sandy wall. As I got closer, I finally saw that someone had carved a line of letters on it, seemingly a few English letters. I was startled and grabbed my third uncle’s hand to shine the light accurately, carefully distinguishing the letters, and I exclaimed, “Oh!”

My third uncle said, “Look at this. Isn’t it the same mark left by your brother in Changbai Mountain?”

I nodded quickly; this was indeed the mark carved by the Mysterious Oil Bottle in Changbai Mountain. I suddenly cursed in my heart: could it be that the Mysterious Oil Bottle had just been here?

“How did you find this?” I asked my third uncle.

He wiped the mud off his face and said, “Don’t worry about that. Can you be sure this is your brother’s handwriting and not someone else’s similar mark?”

I didn’t understand his meaning but nodded to indicate I could be sure. He immediately waved to the man with the black glasses, “Blind man, tell the people above to come down. We’ve found the entrance.”

The man with the black glasses responded, went out, and signaled to those above.

I asked my third uncle what was going on, and he said, “Take a good look at this mark. Can you feel any difference compared to the one carved in Changbai Mountain?”

“Different?” I couldn’t grasp my third uncle’s meaning at first. I leaned in to look and suddenly noticed that this mark had a grayish color.

The mark is engraved on the sandy soil, which is not suitable for carving anything because, although hard, it is very brittle. If you apply too little force, you won’t leave any trace; if you apply too much, the whole piece of sand may crack. This mark is somewhat complex, and it’s clear that a lot of care was taken while carving it. The gray color is a sign of the sand’s oxidation over the years. The gray tone of the mark blends almost perfectly with the surrounding sand, indicating that this mark has evidently been here for quite some time.

“That’s not right,” I said in confusion. “Is this an old mark? Let me take another look—”

Uncle San said, “There’s no need to look again. Since it’s handwriting, it can’t be wrong. This is his carving, but it wasn’t made in the last few days; it was left here the last time he came.”