Never Forget the Grudge
In the secret cave, the first thing that caught my eye was the writing that vowed never to forget a grudge—but it seemed Sister Seol and Hwa-eun had noticed something else entirely.
On the stone wall, martial formulas and other inscriptions had been carved.
“This is!?”
“It's the formulas of the Five Poisons Returning to Origin Divine Art. So-ryong!”
“Why would this be here?”
“This is the martial art So-ryong learned?”
Just as Hwa-eun said, these were the formulas of the Five Poisons Returning to Origin Divine Art along with the advice needed to master it. I scanned them with startled eyes, thinking they might help me—until I reached the final line and found something I could scarcely believe.
If you accumulate the five poisons and reach the eleventh stage, sever the necks of the five venomous creatures you have accepted, drink their vital blood, and take ginseng, angelica root, poria… boil them for three days, form them into pills, and consume them. Only then can you surely achieve great success in the Five Poisons Returning to Origin Divine Art.
Are these bastards actually insane!?
The art clearly took the Beast Heart Technique as its root, so the cultivator’s mind would be linked to the venomous creatures—yet the advice was that once you reached the eleventh stage, you should cut the throats of the very beasts whose spirits you shared, drink their blood, boil their bodies like dog-meat liquor, and swallow the pills. They said the Five Poison Sect had been wiped out for treating beasts like trash. These people truly had been monsters.
“Hwa-eun, lend me the lantern for a moment.”
“The lantern?”
I borrowed it from her, pulled out the oil lamp inside, and immediately scorched the inscription until no one would ever be able to read it again. Flame and smoke blackened the characters at once. Back on Hainan Island I had eaten snakes when I was starving, but those had been wild snakes. Raising children whose minds and hearts you shared, then slaughtering them, boiling them, and swallowing them as pills—evil like that had to vanish.
This kind of madness has to disappear. Drinking your daughters’ blood and boiling their bodies to eat them? What kind of abominable martial art is that!
Since I had already mastered the Beast Heart Technique itself, I could search for another path. I felt no regret as I rendered every last character illegible. When I finished, Hwa-eun and Sister Seol patted my shoulders with approving looks.
“Well done, So-ryong.”
“That’s my little brother.”
Only then did they notice the writing I had spotted first. Staring at the characters that looked as though they had been written in blood, both of them gripped their chins with grave expressions.
“Ah… and it seems pretty certain there are survivors of the Five Poison Sect.”
“Right. Hwa-eun, this really does look like it was written in blood…”
It was undeniable proof. Perhaps it was the vow of those left behind on the far side, swearing revenge because they could never return.
“We’ll have to be careful going forward.”
“Yes. And from the looks of this writing, we probably won’t be able to go back unless someone opens it from the other side.”
“True enough…”
After carefully checking the surrounding mechanisms, Hwa-eun spoke with open regret.
“As I thought, there’s no way to open anything from this side. I wish I’d examined the other side more carefully. What a shame.”
She had clearly been curious about how the mechanisms worked; failing to confirm the principle even on the opposite side left her disappointed. We inspected the sealed stone wall and every inch of the surroundings, yet nowhere could we find any trace of a device that would open the door. Just as Hwa-eun said, it felt as though the passage could only be opened from within. Any apparatus that might reveal the operating principle had been thoroughly concealed.
“Then I guess we have no choice but to keep going forward. Judging by the lack of human traces ahead, this place has been abandoned for a long time—but let’s move carefully.”
“Yes, Sister Seol. Shall we?”
At Sister Seol’s words, Hwa-eun and I nodded and started ahead, though Hwa-eun still wore a faintly disappointed face.
We had not taken more than a few steps before we were forced to stop.
What appeared before us was a vertical shaft dropping more than ten meters straight down. I had wondered why precious martial formulas would be carved on the door of a passage; now it made sense. From the far side no one could climb up, so this space was essentially a sealed chamber.
With Yo-hwa and Cho’s help we descended into the pit and prepared to hurry on again—until Hwa-eun, once she stood at the bottom, caught my shoulder.
“So-ryong… this cave feels strange.”
“You’re right. It’s different from any natural cave we’ve seen so far.”
Looking around again, I had to agree. The long tunnel stretching away from the base of the shaft was uncanny. It lacked the natural feel of the paths we had walked until now, yet calling it artificial also felt wrong. Excavation techniques in this era were hardly advanced, yet somehow a perfectly circular tunnel roughly three meters across continued endlessly. The walls were not earth but rock-hard, their surfaces rippled in a single direction—less as if they had been carved and more as if they had been melted.
“It’s like the rock was melted away, isn’t it?”
The strange atmosphere Sister Seol and Hwa-eun described matched what I felt. Yet somewhere in the back of my mind the sight was familiar. I was certain I had seen something like it before. When I tried to place the memory, one I had pushed aside long ago rose hazily to the surface.
I’ve definitely seen this somewhere… Wait—could it be!?
I quickly checked the floor. It felt solid under my palm, yet when I scraped the surface with the short blade I carried, the rock gave way. Stone, yes—but a strangely soft stone.
That was when I remembered exactly where I had seen it.
This place reminded me of the Củ Chi tunnels I had once visited as a tourist while collecting specimens in Vietnam in my previous life.
The guide said Vietnam has a lot of clay mixed with lime, so it’s easy to dig, and once the surface hardens it becomes extremely solid—no supports needed.
The Củ Chi tunnels, the two-hundred-fifty-kilometer network built by the Viet Cong during the Vietnam War, were a famous tourist site. The walls of this cave felt exactly like that lime-mixed clay that had dried rock-hard. The soil itself had triggered the memory. And when I thought about it, Mt. Namna sat right on the border between Yunnan and Vietnam.
I turned to Hwa-eun.
“This looks like it was dug through clay mixed with lime.”
“People dug all of this?”
Sister Seol’s eyes widened at my words, but when I thought about it, martial artists were absolute monsters at hard labor. Their bodies were living cranes; if they had excavated this with trained internal energy, it suddenly made sense. In my previous life hundreds or thousands of Viet Cong had dug the tunnels, but a few dozen martial artists could probably achieve the same efficiency.
“If we’re unlucky, this tunnel might be a lot longer than we think.”
“Longer?”
“If people dug it, how long could it really be?”
Everyone brushed off my warning—until we had walked until we were ready to drop from exhaustion, and only then did they whisper with defeated faces.
[Our ancestors were right. Those Five Poison Sect bastards really were crazy.]
[They’re definitely not normal, Unni.]
We must already have covered dozens of kilometers, and the tunnel still looked ready to hit two hundred.
—Twang.
The spider silk I held from Yo-hwa suddenly sang with a sharp note as it was yanked from behind. Immediately Hwa-eun’s startled voice floated up from the rear of our line.
[Ugh. Unni, why did you stop?]
Hwa-eun had been bringing up the rear; when Sister Seol halted she had walked straight into her back. Then, in the darkness, the quiet voice of our older sister—who had been trudging in silence, worn down by the Five Poison Sect’s insane tunneling—reached us. Even the softest sound bounced along the cave walls and raced ahead, so we kept our voices to the barest whispers.
[Kids… how long have we been in here?]
Hwa-eun’s answer came from my right rear, followed by Sister Seol’s exhausted tone.
[Unni, I’m sure it’s been more than two days.]
[It’s dark and the same path never ends. I feel like I’m going crazy.]
Hwa-eun was right—more than two days had certainly passed. Sister Seol seemed to be hitting mental exhaustion; we needed rest.
I carefully suggested we stop.
[Let’s rest a bit. Get some sleep too.]
[That’s probably for the best.]
[Yes. All right, So-ryong.]
Their agreeing voices came out of the dark. I spoke toward Cho, who had been crawling ahead and now stopped.
[Cho-ya, let’s rest and sleep a little before we go on.]
—Tssrrt!
The reason we had extinguished every light and were following only the silk Yo-hwa had tied to Cho’s body was simple: we had no idea what lay ahead or how far we still had to go. We could not risk light-footwork techniques or loud voices. If a fight waited at the end we needed to conserve energy carefully, and the tunnel might stretch forever—or Five Poison Sect survivors might suddenly appear. So our exploration had been crawling along at an agonizingly slow pace. We had entered boldly, yet now that the tunnel seemed to lead outside we had no choice but to be cautious. We had already seen their blood-written vow of vengeance.
That was why every lantern was out and we advanced slowly, trusting only Cho’s guidance.
—Whoosh.
The sound of a lantern being lit reached us as we sat against the cave wall in the dark. Light bloomed. After so long in pitch blackness even the modest glow of the lantern made our eyes sting as if they might water.
[Ugh, my eyes…]
[Same. We’ve been in the dark too long.]
Once our eyes adjusted to the light we each pulled food from our packs. All Sister Seol, Hwa-eun, and I carried were a little jerky and dried rice cakes. Still, we had to eat.
We chewed while discussing just how much farther this damned cave could possibly go.
[Seriously, how long does this damn tunnel go on?]
[I don’t know, Unni. I wish it would just end already…]
[It would be nice if an exit showed up soon.]
[Ugh, everything else is fine, but I want to eat something different. This stuff is so hard. And more than anything I want grilled meat!]
Sister Seol had clearly grown sick of jerky and dried cakes; she stuffed a piece into her mouth with a miserable face. The Beast Palace ate a lot of hunted game—grilled meat must have been on her mind. I was thoroughly tired of the same rations myself and was nodding along when Hwa-eun, peering in the direction we were heading, tilted her head.
[When we get out let’s eat something delicious, okay? But… doesn’t it smell kind of savory from somewhere?]
[Savory?]
[I’m sure it’s the smell of roasting rabbit…]
At Hwa-eun’s sharp nose Sister Seol flared her own nostrils. A moment later she nodded firmly.
[You’re right! That’s definitely rabbit meat!]
My own nose caught the rich aroma of cooking meat as well. We looked at one another and immediately started moving toward the scent. The smell of roasting meat meant people—and that meant an exit. We were desperate to escape this wretched place, and human traces had finally appeared, so we had to check.
We hurried forward for some time.
A faint light began to show ahead. We instinctively snuffed the lantern we had been carrying and quickened our careful steps.
[From here on we move carefully.]
[Right. Got it.]
[Understood, So-ryong.]
The place we reached, moving with utmost caution, was a dead end with a hole roughly three meters across in the floor. We rushed over and peered carefully downward. Light rose from below along with thin wisps of smoke.
All three of us hung carefully over the edge and looked down.
What met our eyes were six rabbits roasting over a campfire and the people sitting around them.
Hwa-eun checked their faces and her eyes went round.
[Th-those people—how…?]
Wondering why she was so shocked, I looked down myself and immediately understood. We knew those people.
Why the hell are they coming out here?