After struggling for what felt like ages, falling countless times, and nearly being swept away by the gale, the shadows of the Yardang formations finally came into sight, and the wind immediately lessened.

Stepping a few paces further, I spotted what looked like a figure standing beneath a massive boulder, waving something resembling a silk scarf, with the beam of a flashlight dancing ahead.

I pulled out my phone to signal back, and moments later, several dark figures rushed toward me.

Three men approached; seeing I was nearly collapsing from exhaustion, one immediately hoisted me onto his back while the other two supported me as they hurried toward the Yardang cluster.

We reached a giant, wind-eroded archway where * rushed forward, snatched off my scarf, and asked, "Are you alright! The sandstorm hit so suddenly. We were coming to meet you, but the wind was too fierce; we lost two men!"

Against the deafening roar of the wind, I barely caught his words. I’d meant to curse, but hearing about the two lost men cooled my temper. I spat the sand from my mouth and shouted, "What now? Where are the others?"

gestured toward the depths of the Devil City and said, "Boss Wu took Da Xiong and the others inside. They haven't been heard from since yesterday. We're going in to find them now."

I nodded, re-wrapped my scarf, and pointed ahead.

Since I had been there before, and with Da Xiong and Liang Qian absent, I reluctantly took the lead.

Upon entering the Devil City, the strange noises became louder, but the sand and flying stones dropped significantly. Only the sky remained terrifyingly dark, with occasional rocks crashing down from the Yardang peaks above, like heavy rain.

braced against the falling stones and handed me a helmet equipped with a headlamp for mining. I flicked it on, placed it atop my head, and walked on, the sharp pitter-patter echoing above me.

As we walked, I heard a familiar voice calling out from behind us: "Gentlemen, why won't you listen to me? This sandstorm will rage for three days and three nights. We must turn back now, or we'll be trapped and buried alive in the Devil City!"

I looked back. It was the guide, Old Ni. His face was devoid of color; his taqiyah had clearly been blown off by the wind, and his messy, oily hair was whipping around like seaweed in the gale.

He made a gesture of prayer while tugging at *’s sleeve.

ignored him completely, his mouth and nose obscured by a black scarf, leaving his expression unreadable to me.

I knew in my heart it was too late to retreat; even if we wanted to make it back to Ruoqiang, we had to wait here until the worst of the storm subsided.

But I quickly dismissed the thought of sheltering, as * tugged at my coat and pointed ahead.

What I saw made me gasp: the path before us was rising sharply. The already tall Yardang formations had been buried two or three meters deep by the sand. The further we moved, the higher the dunes piled up. If the wind continued like this, this entire Yardang cluster would soon be completely submerged underground.

Seeing this, everyone understood: if we wanted to survive the day, our only option was to take shelter in the underground cavern, which, being naturally subterranean, had structurally sound buildings despite years of erosion—a perfect refuge.

Silence fell over the group; even Old Ni stopped talking. We pushed forward against the wind, struggling onward.

Walking on the soft sand layer was treacherous; every step sank to the thigh, flooding our boots with grit, making progress agonizingly slow.

After about half an hour, the sound of the wind ahead intensified, and the strange noises reached a deafening volume.

Then, through my goggles, I saw * at the front waving his flashlight, signaling us to halt.

I slowly approached him, and the others gathered behind me. Only then did we realize we were mere meters from the massive sinkhole entrance. Ancient machinery around the opening was already half-swallowed by yellow sand, and the violent storm was funneling roaring torrents of sand into the cavity, creating a deep, rumbling echo like a gateway to hell.

turned his military signal flashlight to its highest setting and shone it into the hole, but the stark white beam vanished quickly, as if poured into the sea, swallowed by the distant darkness.

Frowning, * pulled a nylon rope from his backpack, handed one end to me, and pointed toward the nearest heavy-duty excavator.

Understanding his meaning, I walked over, hooked the rope onto the excavator’s wheel hub, pulled hard to ensure it was secure, and gave * a thumbs-up.

looked at the others, made a downward pressing gesture with his right palm—meaning he would go first to check things out—and signaled us to stay put.

He then tossed the rope into the abyss-like opening, donned leather gloves, grabbed the line, braced his feet against the tunnel wall, and began to descend slowly.

Those of us left at the opening dared not venture too close, as the freshly accumulated sand layer was unstable, and one slip could send us plunging into the chasm.

Being a seasoned tomb raider, * signaled with his light toward the surface every minute, indicating he was safe.

After four such signals, I suddenly saw the rope go slack. My heart froze, fearing an accident, but quickly his flashlight beam reappeared, drawing large circles toward the sky.

This signal meant it was safe below. We all sighed in relief, realizing * must have found solid footing and released the rope.

We then began to descend one by one.

I was the last to climb down. From a distance, I saw everyone standing on a ledge that jutted out from the cavern wall. The platform had a slight incline, but due to the oppressive darkness, its dimensions were impossible to judge.

When I reached the bottom, the feel beneath my feet indicated a rock-hewn platform, suspended at least twenty meters above the floor—clearly man-made.

led the way, keeping his flashlight beam ahead, until we reached the edge of the stone platform. We crowded up behind him as he shone his light downward, but the beam was instantly devoured by the profound darkness, just like water flowing into the ocean.

paused for a moment, glanced at me, and said expressionlessly, "It's deep..."

I nodded, pulled down the scarf covering my face, spat twice, and said, "Let’s try a flare."

murmured assent, retrieved a flare gun from his pack, loaded it, and fired a shot straight into the depths of the abyss.

The searing white light instantly burst forth from the pitch-black void, illuminating everything around us.

The dazzling orb descended rapidly, allowing me to see clearly that where we stood was not a simple platform, but a spiraling rock pathway clinging to the cavern wall, winding endlessly downward. Above us, fragments of older rock roads remained, suggesting this path once led directly to the surface, but years of weathering and burial had destroyed the upper section.

watched the light spot shrink and told me, "That’s right. Look at the wheel tracks left on these roads. It’s clear this must have been the channel the Tsarist Russians used to transport the excavated rock and soil with large locomotives."

I agreed; this was certainly good news. At least we wouldn't have to rappel down an unknown depth.

But watching the flare continue its fall, I grew increasingly astonished. Even a magnesium flare, lasting less than a minute, should have plummeted hundreds, perhaps a thousand meters in freefall. Yet, the light had not vanished from view before it was still descending.

Witnessing this, the expressions of those around me varied—some were stunned, others fearful, but some of the younger grave robbers looked distinctly excited.

I, too, felt a complex surge of emotion. To excavate a hole tens of meters wide and a thousand meters deep, even with modern machinery, represented an engineering feat comparable to building the Egyptian pyramids. This was undoubtedly another human marvel, yet this spectacular wonder was infused with a strange, eerie mystery.