The path now became smooth and easy to traverse. We walked on for two hours without encountering anything strange. Then, after passing through a long and narrow enclosure, we climbed atop a terrifically large boulder and shined our lights ahead. Rather than once more illuminating a swatch of total darkness, our flashlight beams instead lit upon the sheer face of a gigantic rock wall.
We stood there gaping for quite some time before we realized what this meant. It was the end of the cave. After we swept our flashlight beams across the wall, it became evident that this was a giant chunk of tectonic limestone. It had been formed hundreds of millions of years ago, when two walls were suddenly forced together by accumulated pressure within the rock strata, creating a single massive rock face. The cave went no deeper. It had naturally sealed itself shut and we had reached the end.
From the pool at the top of the cave we had traveled some four or five kilometers to get here. As far as underground rivers were concerned, this one was rather short. It is much more common to see them stretch for ten to twenty kilometers. Given the amount of water flowing through the cave, we never would have expected it to end so abruptly. All of us prospectors began to talk at once. We felt that for the cave to conclude here was a structural impossibility. Based on the textbook examples as well as on our own experience, this underground river should have extended much farther. The great quantity of water it carried would have to be flushed somewhere, most likely into a lake hidden deep beneath the rock. The main thing we kept talking about was how the river had rushed when it reached the stone-filled shoals, how it had been too deep to see the bottom. It’s not like the amount of water in the river had been lessening the deeper we got. And once that much water arrived here, it would necessarily keep flowing downward beneath the rock. There had to be a descending channel of water somewhere around here, but from where we stood, the cave really did seem to come to an end. Even after looking for some time, we could find no concealed entrance or tunnel.
We were at a complete loss, so we took a short break to assess our situation. Among us, Pei Qing had the most experience with cave exploration. He had worked in Yunnan, where the landscape is riddled with caves and waterways. Normally, he said, the force of the river would have created a small waterfall here. Over time, the water would then cause the rock around it to collapse, blocking off the rest of the cave. The path ahead still existed, he said. It was just hidden beneath our feet.
Wang Sichuan and I both disagreed. If this were the case, then how had the Japanese been able to proceed deeper into the cave?
“We must have taken the wrong branch in the river,” said Wang Sichuan. “One of the other groups is on the right path. But,” he continued, “isn’t this just what we needed? Now we have every reason to head back the way we came.”
I waved off this suggestion. Even if one were to ignore all the signs of long-term Japanese occupation here, the simple presence of the woman having come from this direction was enough to prove that, somewhere around here, there had to be a path that led deeper into the cave.
“Fine,” said Wang Sichuan, “let’s do it like this: We’ll all stop talking, stop making any noise, and just look and listen. If there really is a massive crevice hidden somewhere under the rock, the sound of water rushing through it should be relatively loud.”
Having no alternative, we split up and moved around the cave. Lying with our ears to the ground, we held our breath. Little by little, the faint sound of running water became audible. In all honesty, though, if I was able to detect any difference in the sound from one place to another, it seemed random. As I moved about the cave to better gauge the location of the river, the sound itself changed, now becoming louder, now becoming softer. With great care I attempted to track the sound across dozens of feet of cave floor, but without any luck. Sighing to myself, I yelled to everyone that we might as well give it up. One of the soldiers suddenly jumped to his feet and motioned for us to be silent.
Had he found the hidden channel? We tiptoed over, knelt down, and began to listen. We waited a moment, then, rather than the sound of water rushing beneath the rock, we heard something indescribable, almost like the noise of fingernails scratching against stone. We listened in silence for some time, but were unable to discern just what the sound was. We knew only that this noise, like thorns dragging against a chalkboard, was agonizing. It felt like claws being scraped against our hearts, provoking a terrible itch. All we wanted was to scratch it with all our might.
I’m not sure who was first to begin digging, but in a moment we had all joined in and were tearing the stones from the floor of the cave, first big ones, then the small ones. After having lifted several of the rocks, I realized that something was amiss. They were all far too easy to move. Of the shattered stones that lay nearby, some were large and some were small, but they always had much larger stones beneath them. Somehow, though, not a single one of the rocks from this spot was large enough to prevent us from tunneling deeper. What did it mean? In my curiosity I couldn’t help but increase my pace. This ferocity infected the rest of the group, and we began to work faster and faster. Then, with an audible clang, I knocked against something other than rock.
Everyone paused, stopped what they were doing, and looked over at me. A rust-covered sheet of iron lay beneath the stone I had just pulled from the pit. We stared at it for a moment, our expressions baffled. Then everyone gathered around me, ripping the hole wider. We soon uncovered a massive iron door, fifteen feet long by fifteen feet wide. Mottled green paint peeled from its exterior. The faded outlines of Japanese characters were just barely visible. “Plan 53” was all we could make out. Once the majority of the door had been uncovered, we put our ears to its surface and listened silently. The scratching sound had disappeared and from within the door not a noise could be heard.
CHAPTER 17
The Iron Door
It was a double door made of variously sized sheets of iron welded together. The door was astonishingly thick, with rivets as big as a thumb and overlaid with countless layers of cement and liquid steel. It was set inside a grooved iron frame and was sturdy enough that when we stood atop it, the door neither rocked nor flexed an inch. The two doors would open in unison from the center, where there were three huge torque-operated door handles. They had been welded immobile. Even the tiniest seams between the doors had been welded shut. No matter how hard we pulled, they failed to move at all.
The deputy squad leader gave the soldier at his side a certain inscrutable look, and the latter climbed onto the door and pressed down on it with all his weight. “It’s blastproof,” he said in a quiet voice. “There’s a false layer within the iron sheeting filled with mechanical springs and cotton batting.”
“Seems when the Japs left they had already decided not to return,” whispered Wang Sichuan. We all nodded.