The two climbed down the rope ladder and brought out their torches.

Sure enough, not far away, they spotted a stone house. The house was squat with a rounded roof and two round windows that looked like a pair of big eyes—it actually looked kind of cute.

Cen An instinctively lowered his voice. “Is anyone inside?”

Su Rui shook his head. “No one. But there seems to be a faint presence nearby—not a mutant beast.”

If not a mutant beast, then perhaps just an ordinary animal? Still, it’s good that there’s no one inside.

Cen An was incredibly curious about this house. Who on earth would live inside a mine shaft? Although that senior from the tenth level also lived here, his place was clearly just a temporary shelter.

But this person had actually built a house.

Protected by Su Rui, he walked up to the stone doorway. On either side of the door stood two equally plump statues, each about knee-high. Cen An held up his torch to examine them closely and finally recognized them—they looked like two little dogs.

Guardian beasts? For some reason, he felt a sudden fondness for the owner of this stone house. To have such a sense of life’s little joys in such a barren place—this person couldn’t be a bad person.

The only question was whether the owner was simply out or had already left for good.

The door itself was made of wood. Su Rui stepped forward and gave it a push; to their surprise, the lock fell right off.

Cen An peered at it. “It’s completely rotted through.”

If even the lock had rotted, it seemed the owner had been gone for quite some time.

The two pushed the door open and stepped inside.

The interior wasn’t large, with no partitions; one could see right through to the far end: a stone table, a stone bench, and a stone bed. In the corner stood a small, makeshift earthen stove and a small pile of unused firewood and dry grass.

The only items that could be considered valuable were probably the three stone chests stacked against the bed, though they had no idea what was inside.

“Look at this,” Su Rui’s voice called out. Cen An looked up to see him standing before the stone table, holding something aloft.

As Cen An stepped closer, he realized it was a thin stone booklet—made of mica sheets of uniform thickness and size, bound together with iron wire, looking remarkably like a notebook.

He couldn’t help but remark, “That’s truly fine craftsmanship.”

Over the years, the iron wire had rusted and snapped. He carefully flipped open a page, and sure enough, characters were engraved upon it.

“Thirty years have now passed since the Cataclysm. My friends have been scattered, my relatives have perished. I have not sought to survive by hiding underground, but have lived alone, feeling profoundly desolate. I have committed all I have seen, heard, thought, and felt to this stone tome—which will not decay for a thousand years nor crumble for ten thousand—to await future generations…”

Cen An took a light breath. “How many years have passed since the Cataclysm?”

Su Rui replied with absolute certainty, “Three hundred years.”

Cen An recalled it being the same; in other words, this was an ancient person who lived three hundred years ago. Given such a long span of time, the owner of this room had likely already passed away.

He sighed and continued reading.

The following pages were filled with the owner’s heartfelt longing for family and friends; the words were so sincere that even Cen An couldn’t help but feel a pang of sadness.

Further on, however, were the owner’s accounts of what he witnessed after the Cataclysm. He wrote, “I have seen with my own eyes ordinary animals mutate into mutant beasts, their bodies suddenly swelling and fangs sprouting.” He also described how land that had once been suitable for farming withered after a blood moon, becoming permanently barren…

This made Cen An feel grateful that he had traveled to a world three hundred years in the future; though barren and dangerous, it was, after all, relatively stable.

The handwriting of the home owner gradually faded—likely due to his failing health—yet his demeanor grew much more serene. In his spare time, he began studying the layout of the mine.

“The world after the cataclysm is truly wondrous. These mines appear randomly, ranging from thirty to a hundred levels deep. Once the ore is harvested, it reappears within fifteen to thirty days. Could this be heaven’s compensation to humanity?”

“…This mine has a total of sixty levels. Due to the interference of spatial forces, the entrance appears at random locations, emerging once every three months—only those destined to enter may do so. Furthermore, between the twentieth and thirtieth levels, there is another exit. This exit also appears randomly: in the morning, the probability is… in the afternoon, the probability is…”

Cen An immediately took note. This differed from what the elder on the tenth level had said; according to the host’s observations, the entrance could appear at any time of day, though the probabilities varied. For instance, the probability of it appearing in the morning was 60%, in the early evening 77%, while the probabilities for the afternoon and late night were 10% and 20%, respectively.

“I’ve been fortunate enough to encounter the exit several times, and only then did I realize that the exit’s spatial stability is unreliable; one must not enter or exit at will. Special materials are required to craft a ‘door’ that anchors the entrance, ensuring safe passage.”

“…After three months, I have devised the formula for the ‘door,’ which is as follows: Spatial Stone x3, Stellar Iron x5, Yellow Earth Pollen x6, Sky Blue Sapphire x4… Silver Ore x20, Copper Ore x50, Iron Ore x100.”

“Additionally, the ‘door’ requires a key to open. The formula for the key is as follows: Void Essence x1, Starlight Ore x1, Gold Ore x10.”

After reading this, Cen An’s hands trembled three times… How to put it? Don’t be fooled by the fact that the key recipe only requires three types of ore—the difficulty of collecting them is no less than that of the ‘Gate’! You must know that the drop rates for Void Essence and Starlight Ore are extremely low; if you’re unlucky, you might not find them even after farming for half a year.

As for the ‘Gate’… Cen An could only give a wry smile. With so many ores—and not just any ores, but a mix of high-grade, mid-grade, and low-grade ores all bundled together—who knows how long it would take to collect them all… Maybe he should just wait until the upper entrance opens in three months?

He shook his head, only to discover there was another page. This page listed Mica, which was only half the size of the ones on the previous page—he really hadn’t noticed it earlier.

“After half a year, I have still failed to gather all the ingredients required for the formula. My time is now nearly up… Should anyone come here, please bury me in the stone pit behind the house; there is no need for a tombstone. The contents of the stone chest are my token of gratitude.”

Cen An gently closed the stone tome and sighed; the homeowner had indeed passed away.

The system, however, couldn’t resist chiming in, popping up a notification: 【Congratulations on obtaining the recipe: Portal of Space】

【Congratulations on obtaining the recipe: Key of Space (requires use with the Portal of Space)】

Cen An raised an eyebrow slightly. So you could collect recipes even after crossing over? That wasn’t bad at all.

He took his time closing the prompts and looked around. Since the owner had passed away, where were the remains?

Su Rui, with his keen senses, heard his question and pointed to the bed. “Right there.”

Cen An peered over and saw, beneath the blankets, a set of remains.

“I’m starting to think this mine shaft isn’t so bad after all.” Cen An pondered for a moment.

The monsters in the mine shaft wouldn’t venture beyond their own level, and with this stone house providing shelter, the former owner’s remains could be kept intact. Out in the open, things wouldn’t have been nearly this peaceful.

Together with Su Rui, he carried the remains outside, where a stone pit had indeed already been dug behind the house.

The two cleared out the pit and laid the former owner to rest inside.

After three hundred years, the homeowner had finally found peace.

Cen An gathered fresh flowers and food and performed a simple memorial service. When he returned to the stone house, he found Su Rui already studying the stone box.

The stone box was as big as a suitcase and looked heavy—it was a wonder he could even lift it, let alone turn it over to examine the bottom.

“What are you doing?” Cen An asked, puzzled.

Su Rui scratched his head. “Looking for the opening. How do you open this stone box?”

Cen An looked at him with concern. No matter what, the opening wouldn’t be at the bottom, would it?

He had Su Rui put the box down, took a look himself, and smiled. “It’s a mechanical lock.” 

He really does know how to open this thing.

He didn’t have many toys as a child, but he had actually played with combination locks before. Back then, their orphanage had been selected by a university to be a designated aid recipient.

Those older university students sent over lots of toys, and the other kids would all scramble for the brightly colored toy cars and dolls.

He was a quiet child; he could entertain himself with a mechanical box that no one else wanted. Over time, that box became his very own toy.

The stone box was too heavy for him to flip over, so he directed Su Rui to toss it back and forth a couple of times. With a click, a crack appeared in the top half of the box.

Su Rui opened the top, and sparkling objects rolled out.

“What is this…” Cen An exclaimed in delight. “Spatial Stones? Yellow Earth Crystals, Coral Jade… Hey, there’s even a sky-blue sapphire?”

The gems scattered across the floor, their colors vivid and dazzling; some even emitted strange vibrations.

It was obvious that the first chest contained the “door” recipes collected by the house’s owner. Although the collection wasn’t complete, it covered most of the ingredients, saving him a great deal of effort.

Besides, he still had plenty of ore in his own backpack!

The two followed the same procedure to open the second chest.

As soon as the chest opened, a pile of gold ore rolled out—it was indeed the recipe for the key. Cen An happily stowed the ore away.

The two didn’t rush to open the third chest; instead, they took the ore they had gathered and began cross-referencing it with the recipes one by one.

The iron ore chest contained 64 pieces, and Cen An had 47 in his backpack—that was more than enough; the copper ore chest held 35 pieces, and he had 37 in his backpack—that was also sufficient; silver ore required 20 pieces, but there were 23 in the chest alone, and he had quite a few in his backpack as well…

As Cen An continued to cross-check, he found that among the basic ores, he was short 12 pieces of quartz and 3 pieces of gold ore.

Among the intermediate ores, he was short 2 pieces of white crystal, 5 pieces of pink crystal, 5 pieces of emerald, 6 pieces of topaz, and 2 pieces of amethyst.

As for advanced ores, Cen An hadn’t encountered them yet, so whatever was in the chest was all he had. Thus, he was short 1 Spatial Stone, 2 Stellar Iron, and had none of the Yellow Earth Core, leaving a total shortage of 6… he was also short 2 Sky Blue Sapphires and 1 Starlight Ore.

Cen An quickly ran through the list in his mind. The basic ores weren’t a big deal; he could collect all the Quartz and Gold Ore by exploring just two mine shafts.

Although there were many intermediate ores, they still had to make their way up to the 30th floor, so they definitely wouldn’t run short in the final 10 floors.

The biggest issue was the high-grade ores. Don’t let the small shortfall fool you—this stuff is purely a matter of luck. If you have it, you have it; if you don’t, you’re screwed…

I wonder if the senior wants to go out. If he does, I could ask him if he has any usable ores on hand…

He ran through the idea in his head, then went to open the third chest.