Xu Qian returned to the Xu Family estate with clenched fists, every step heavier than the last. The moment she crossed the courtyard, the sounds of angry voices echoed from the main hall. Servants hurried about with lowered heads, afraid to meet anyone's eyes. The atmosphere was suffocating.
Her father was furious.
She didn't even need to ask why.
Everything had changed because of one man.
Mu Che.
Ever since his return, Xuanwu City had been turned upside down.
The balance that had endured for generations had collapsed almost overnight.
The Ten Noble Families no longer dictated the city's future. The Zhu Family had suffered devastating losses, their authority shattered. Tian Heng's once-formidable underground network had been dismantled piece by piece until nothing remained but scattered remnants. Every move intended to weaken the Jin Family had instead strengthened it.
Now the Jin Family stood at the center of Xuanwu City.
No...
They had become the center of the entire political landscape.
With the Lunar Blossom Sect relocating to their territory, alliances expanding in every direction, and even the Qiang State reaching out diplomatically, their influence had surpassed anything the Xu Family had imagined possible.
Even the Xu Family—the strongest of the original noble houses—could no longer confidently claim superiority.
Xu Qian bit her lower lip.
She hated admitting it.
She still remembered the day she had tried to steal Mu Che's hair dye formula, believing she had outsmarted a mere merchant.
Instead...
He had played her from the very beginning.
Every step she took had unfolded exactly as he had intended.
Then he married into the Jin Family.
Overnight, touching him had become politically impossible.
When news of his death reached the city, she had secretly celebrated.
Not openly.
Just enough to satisfy the resentment buried in her heart.
She had believed fate had finally corrected itself.
Then...
He came back.
Not merely alive.
But as a cultivator.
A man whose return had shaken the entire city.
The Zhu Family's army had been defeated.
Their ancient generator destroyed.
Even their ancestor had failed.
The Shu Family's assassination attempt had ended in disaster.
The Jin Family's influence continued growing with every passing day as refugees, merchants, and cultivators alike flocked to their banner.
At this rate...
No one would ever dare call the Jin Family weak again.
Across the city, another man wore an equally grim expression.
Zhang Jin sat alone inside his study, his hands slowly tightening into fists.
He had underestimated Mu Che.
Repeatedly.
Once, Mu Che had merely been a talented merchant.
Then a capable inventor.
Now...
He possessed both influence and personal strength.
The most dangerous combination imaginable.
Killing him openly was impossible.
Scheming against him had become nearly impossible.
Even approaching him now meant dealing with the Jin Family's growing network of allies.
Zhang Jin slowly closed his eyes.
The reason he had pursued Xu Qian had never been love.
Marriage to the Xu Family would have united two great houses, creating enough influence to rival the Jin Family.
At least...
That had been the plan.
Now it was meaningless.
Even a combined Xu and Zhang Family would struggle to stand against the political and military weight gathering around Mu Che.
His father's warning resurfaced in his mind.
"The Xu Family has outlived its usefulness."
"Before the invasion begins..."
"We leave Xuanwu City."
The Wu Clan was losing patience.
The coming conflict would no longer be fought through politics alone.
Zhang Jin lowered his gaze.
The decision had already been made.
His family would survive.
Whatever the cost.
A cold thought crossed his mind.
Xu Qian...
You played your part.
But this...
This is no longer about ambition.
It's about survival.
Outside, the city continued its daily bustle, unaware that while one family rose to unprecedented heights, another was already preparing to abandon everything before the storm looming beyond Xuanwu City's walls finally arrived.
=============
Yun Che arrived at the source of the signal, landing lightly as his gaze swept across the surroundings. The air was still, almost too still, as if something beneath the surface was waiting.
Before he could take another step—
He stopped.
Then turned.
"Why are you following me?"
Mulan froze for a brief moment, caught.
"I…" she hesitated, her voice softer than usual. "You were going somewhere… I thought I could at least make sure you're safe."
Yun Che raised an eyebrow, clearly unconvinced. "Really?"
Mulan frowned slightly, her cheeks faintly flushing.
"I can't help it, okay?" she said, a bit more defensively. "Seeing you go off by yourself like that…"
She looked away for a second. "It just… doesn't sit right with me."
Yun Che crossed his arms, studying her. "I'm really strong, you know."
"I know," she replied immediately.
A pause. "…Still."
For a moment, neither of them spoke.
Then Yun Che sighed. "Fine."
He turned back toward the signal.
"Stay close. If something happens, don't act on your own."
Mulan nodded quickly, relief flickering across her face.
And just like that—
She followed him.
Not from the shadows anymore.
"Where are you going by yourself?" Mulan asked as she followed a step behind him, her eyes scanning the quiet coastline.
"I picked up something here," Yun Che replied, his gaze sweeping across the terrain. "Might as well check it out."
Even as he spoke, something about the location bothered him. The signal had led him dangerously close to the invasion zone the Wu Clan was preparing. The sea was just ahead, its waves crashing softly against the rocks. It was too exposed. Too deliberate.
Why here?
He slowed. "Hm… nothing…"
Then his eyes narrowed. "Wait…"
He focused.
The crimson hue of his Sharingan flickered to life, and his vision sharpened. Layers of perception peeled back as he activated Eagle Vision, scanning beyond the surface—beyond what ordinary sight could perceive.
"Let's see what you're hiding…"
Moments passed.
Then—
"Jackpot."
He moved toward a jagged rock formation near the shoreline and crouched slightly.
"There it is…" Embedded within the stone was a hollow indentation.
Not natural.
Deliberate.
The hollow indentation of the Fire Booster Key.
He eyes the hollow indentation and Mulan.
Again and again.
No, could it be?
Mulan stepped closer. "Did you find something?"
Yun Che smirked faintly. "Yeah."
He glanced at her. "Turns out, you following me… was actually useful."
She blinked. "Eh?"
"You still have the new Fire Booster Keystone I gave you?" he asked.
"Yes," she nodded, quickly retrieving it. It was the new Fire Booster keystone alongside the new Fire Booster gauntlet on her right arm. The version that Yun Che made for her after she blew the one Mu Che made.
Without another word, Yun Che took the keystone and pressed it into the hollow.
A perfect fit.
For a split second—
Nothing happened.
Then—
A low, mechanical rumble echoed beneath them.
The rock formation shifted.
Stone parted.
And what revealed itself…
Did not belong to this world.
A smooth, metallic panel emerged from within the stone, completely out of place among the ancient surroundings.
At its center—
A numeric keypad.
Clean. Precise.
Digits glowing faintly.
0 to 9.
English numerals.
"What in the… a numerical numpad?" Yun Che muttered, staring at the metallic panel now embedded within the rock.
"Numerical…?" Mulan echoed, clearly confused as she leaned closer.
"Yes, it's—" Yun Che began, about to explain.
Then he stopped. His expression shifted as multiple presences approaching fast.
"Ara… took you long enough."
Yun Che turned around.
Retsu stood there, smiling gently.
Mio beside her, arms crossed with a faint grin.
Behind them—
Everyone else.
Little Fairy. Chu Yueli. Qingyue. Cang Yue. Xue Ling. Lin Yueru.
Even Xue Yin.
Yun Che stared.
Then slowly facepalmed. "I said… come find me if I take too long."
Retsu tilted her head slightly, her smile unchanged. "Yes… we did."
"It's only been ten minutes," Yun Che replied, his voice flat.
"Originally, yes," Mio added casually. "But since Mulan followed you…"
Her grin widened. "We figured we might as well do the same."
Yun Che's eye twitched slightly as he looked at the entire group.
"All of you?"
No one denied it.
Qingyue stepped forward, her expression calm, almost unreadable.
"Yes," she said plainly. "Wives shouldn't leave their husband alone for too long especially with another woman with him."
A pause.
Yun Che sighed as Qingyue's jealousy wasn't exaggerated on the system's database.
"…I'm surrounded."
"Yuu-sama, this is…"
The voice came from ahead of him.
Yun Che blinked—then looked down.
Nemu was already there beside the keypad.
Examining it.
"…Nemu?" he said, momentarily caught off guard. "Since when did you—"
He stopped midway, then exhaled. "…Right. Of course."
Nemu tilted her head slightly, still focused on the device.
"Yuu-sama… since when did english numerical keypads exist in this world?"
Yun Che crossed his arms, his gaze fixed on the metallic panel.
"I was about to ask the same thing." A brief pause. "English numerals too…"
That alone narrowed the possibilities.
Severely.
That could mean one thing as there's only one person on this world could speak and write in English.
Mu Che himself.
It means this place is probably his hideout which needed Mulan's keystone to unlock.
Nemu traced the edges of the keypad lightly without touching the buttons.
"This requires a password," she said calmly. "The structure suggests it is a locked access mechanism."
Her eyes flickered slightly.
"I believe this rock formation is merely a concealment layer."
"A gateway," she added.
"To something hidden." Yun Che nodded slowly. "And if that's the case…"
His eyes sharpened.
"Then there's only one person this could belong to since he is the only one understood English in this world before we came along."
"Mu Che," Nemu finished.
The group fell into brief silence.
Mio stepped forward, cracking her knuckles slightly. "Can't we just smash it?"
Yun Che shook his head immediately.
"No."
He looked at the keypad again, his expression serious now. "If Mu Che built this… then he didn't do it carelessly."
His tone lowered. "There's definitely a security system behind it."
He glanced at Mio. "If we force it…"
A brief pause. "Whatever's behind this door…"
"…might get buried before we even see it."
"Eh?" Mio blinked, clearly unsatisfied with the answer.
Retsu folded her arms lightly, her gaze resting on the keypad. "Hmm… then how are we supposed to figure out the password?"
Nemu glanced toward Yun Che. "Have you tried using Eagle Vision, Yuu-sama?"
Yun Che nodded and activated it again. The world shifted in his perception, faint traces revealing themselves across the keypad. After a moment, he exhaled.
"Yeah… I can see which numbers were pressed."
He straightened slightly.
"1, 5, 9, 4, 3."
The group leaned in.
"But that doesn't solve it," he continued. "There are thousands of possible combinations. Repeated digits are also possible, and most passcodes are six digits."
He shook his head. "This only gives us part of the puzzle."
A brief silence followed.
Then—
Yun Che paused. "…Wait."
His eyes shifted. "Mulan."
She blinked. "Yes?"
"When you were with him… did he ever mention any numbers? Anything unusual? Words, phrases, habits?"
Mulan frowned slightly. "Why does that matter?"
Yun Che crossed his arms, thinking aloud. "Mu Che knew you wouldn't understand certain things. But that doesn't mean he wasn't leaving clues."
He glanced at the keypad again. "He might not have been speaking to you directly… but through you."
The others went quiet.
"Like the English instructions on the Domain Expansion manual he gave you," Yun Che added as Mu Che somehow knew someone that understand English will come to the Jin Province.
Mainly him.
"There's a manual?" Xue Yin asked, surprised as she didn't know Domain Expansion has a manual. The legendary domain technique lost in time.
"Yeah," Yun Che replied briefly. "We'll deal with that later."
He turned back to Mulan. "Think carefully."
Mulan closed her eyes.
Memories surfaced—small things, insignificant at the time.
The way Mu Che spoke.
The things he repeated.
The habits she never questioned.
After a few seconds, her eyes opened.
"I… don't know if this matters," she said slowly.
Yun Che didn't interrupt. "He used to make this dish a lot."
"A dish?" Retsu asked.
Mulan nodded. "He called it… 'pie.'"
The word hung in the air.
Yun Che froze.
"Pie?" he repeated.
"Yes," Mulan said. "He made it with fruits. It was his favorite."
She hesitated slightly. "I liked it too…"
A brief pause. "…It's an English word, right?"
"Yes… it's a dish," Yun Che said, still processing. "But why bring up pie all of a sudden?"
Mulan shifted slightly, uncertain. "I don't know… it's just something he always did. He kept making it. Serving it. He even said it was his favorite."
Qingyue tilted her head. "What is a pie?"
Yun Che blinked once, then answered almost automatically.
"A pie is a baked dish made with a pastry crust. It can be filled with fruits, custard, nuts… even meat. It can be sweet or savory, served hot or cold…"
He paused mid-sentence.
"…Why am I explaining pie right now?"
A soft chuckle followed.
"Ara… we can try it later," Retsu said with a gentle smile, clearly intrigued. "Please teach us how to make this 'pie.'"
Mio nodded beside her, unusually focused on the idea. "Sounds interesting."
Yun Che stared at them both.
"…We are standing in front of a hidden mechanism possibly tied to Mu Che's secrets," he said flatly. "And you two are thinking about dessert?"
Neither denied it.
Yun Che let out a long sigh, rubbing the back of his head as the tension momentarily gave way to something almost mundane. "Okay… okay… we can make pies tomorrow—" he began, half-resigned to Retsu and Mio's sudden interest.
Then he stopped.
Mid-sentence.
His expression froze, eyes narrowing as a thought struck him with sudden clarity.
"Yuu-kun…?" Retsu called softly, noticing the shift.
Yun Che didn't answer immediately. His gaze slowly drifted back to the keypad, mind racing as the pieces began to align.
"Wait… wait…" he muttered under his breath. "Pie…"
A pause.
Then—
"Not pie…" His eyes sharpened. "…Pi."
The realization settled in.
"It all makes sense," he said, stepping forward. "The numbers… the pattern… he wasn't talking about food."
Retsu blinked, clearly lost. "We don't understand…"
"Nemu," Yun Che called, his tone turning precise. "Not pie as in the dish."
He pointed toward the keypad. "Pi. The constant."
Nemu's eyes flickered with understanding, though she remained composed. "But Pi is an infinite sequence," she said.
"Exactly," Yun Che replied immediately. "Which means he only expects a fragment."
He stepped closer, gaze locked onto the keypad.
"The first six digits."
There was no hesitation.
"Three. One. Four. One. Five. Nine."
"Input 314159."
Nemu nodded once and moved forward. Her fingers hovered briefly over the keypad before pressing each number with precise, deliberate motion.
For a moment—
Nothing happened.
Then the ground beneath them trembled.
A deep rumble echoed outward as cracks spread across the rock formation, splitting it apart from within. The stone façade that had concealed the mechanism began to collapse, fragments breaking away and falling to the ground.
What lay beneath it—
Was not of this world.
A smooth metallic surface emerged, flawless and cold, untouched by time. At its center stood a sealed door, its edges glowing faintly as hidden mechanisms activated.
With a low, controlled hiss—
The door opened.
"Wow..."
Nemu's voice echoed softly through the metallic corridor as she stood beside Yun Che. The hidden facility stretched far beyond the entrance, its smooth alloy walls untouched by rust despite having been buried beneath the mountain for who knew how many years. White ceiling lights flickered intermittently as emergency power continued to function, bathing the passageway in a pale glow.
Yun Che swept his gaze across the corridor before turning toward the group with a grin.
"Since we're all here..." he said, gesturing deeper into the facility. "Up for a little exploration?"
"Might as well," Retsu replied with a small shrug as she casually fell in behind him.
One by one, the others followed. Mio and Nemu walked close behind Yun Che, their eyes constantly examining the unfamiliar technology surrounding them. Cang Yue and Qingyue admired the strange architecture, while Little Fairy and Chu Yueli remained alert, instinctively keeping watch despite not understanding what they were seeing.
Behind them came Xue Ling and Xue Yin, with Mulan quietly bringing up the rear.
Every step carried them deeper into a world that simply did not belong on the Profound Sky Continent.
"How long has it been since anyone came here...?" Yun Che murmured.
Almost instinctively, he activated Eagle Vision.
The world shifted.
Colors dulled.
Important details began to stand out.
Then...
His pupils narrowed.
A trail.
Faint.
Almost invisible beneath years of dust.
Dried blood.
It wound its way along the corridor before disappearing around a distant corner.
Yun Che's expression hardened for the briefest moment.
His eyes slowly drifted toward Mulan.
She walked calmly beside him, completely unaware of what he had found.
He said nothing.
For now.
If the blood belonged to Mu Che...
Then whatever had happened inside this facility had not ended peacefully.
"...This place really is out of this world," Mulan said softly as she looked around in amazement. "Could this be..."
Yun Che nodded.
"I'd say this was Mu Che's laboratory."
Mulan unconsciously stiffened.
The place where Mu Che had spent countless hours creating inventions...
The place he had never spoken much about...
Now lay abandoned before her.
The group continued deeper until the corridor widened into a vast chamber.
Rows of enormous cylindrical containers stood upright along both walls, each one housed inside reinforced steel compartments stretching toward the ceiling.
Yun Che stopped abruptly.
"...Wait."
His gaze swept across the room.
"Nemu..."
She had already stepped forward.
Her fingers brushed against the metal casing as she examined the structure, tracing welded seams, maintenance hatches, and reinforced locking mechanisms. The more she observed, the more serious her expression became.
A moment later, she slowly turned around.
Her eyes had widened.
"...There's no mistake."
She took a slow breath.
"These aren't storage cylinders."
Her voice became firm.
"They're missile silos."
Silence fell over the chamber.
"...Missiles?" Cang Yue repeated blankly.
Yun Che stared up at the towering launch tubes, his expression turning increasingly complicated.
"They're vertically launched..." he muttered. "Reinforced blast chambers... launch rails..."
He slowly exhaled.
"So he wasn't just experimenting with firearms..."
His eyes swept across the dozens of empty silos.
"He was developing missiles."
The realization settled over everyone.
Until now, they had assumed Mu Che had simply possessed knowledge from a technologically advanced civilization.
This discovery changed everything.
Yun Che folded his arms.
"At this point..."
He let out a dry laugh.
"...I think we can safely assume Mu Che came from the modern world."
No one disagreed.
There was simply no other explanation.
No native of the Profound Sky Continent could have conceived of missile launch systems, reinforced silos, and advanced metallurgy centuries beyond the continent's understanding.
Mulan slowly turned in place, her fingertips brushing against the cold metal of one of the massive launch tubes. The chamber was silent, save for the faint hum of machinery that had somehow survived the passage of time.
Her shoulders gradually slumped.
"...Why?"
Her voice was barely above a whisper.
"Why didn't he tell me about this place?"
She looked around at the immense underground facility, every corridor revealing another secret she had never known existed.
"...Did he never trust me?"
The question lingered in the air.
Yun Che remained silent for a few moments before answering.
"I think..." he began carefully, "Mu Che came from a world similar to mine."
Everyone turned toward him.
"He was the only other person I've encountered who understood English. That alone tells me we shared a common origin—or at least a similar civilization."
He glanced around the laboratory.
"Looking at this place..."
"...I'm even more convinced."
Mulan lowered her gaze.
"But... why keep it from me?"
Yun Che sighed softly.
"Mulan."
She looked up.
"You've seen what he built."
He gestured toward the towering missile silos.
"This wasn't the work of an ordinary inventor."
"This is the work of a genius."
His eyes swept across the facility.
"An intellect decades—perhaps centuries—ahead of this world's technology."
He paused before continuing.
"Now imagine someone like that."
"Thrown into an unfamiliar world."
"No modern tools."
"No factories."
"No engineers."
"No one who even understood the language and concepts he carried."
"He woke up with knowledge that no one around him could comprehend."
Mulan quietly listened.
"He also had a weak body," Yun Che continued. "He couldn't rely on overwhelming cultivation to protect himself. His greatest weapon was his mind."
Yun Che met her eyes.
"You and he were married because your interests aligned."
"It was a political and practical arrangement."
He didn't say it harshly.
Only honestly.
"At that point... could he truly trust you with secrets like these?"
Mulan's lips parted slightly.
"And even if he had..."
Yun Che's tone softened.
"...would you have believed him?"
Silence.
"If he had told you he came from another world..."
"...that these weapons were designed using knowledge thousands of years beyond this continent..."
"...that he intended to build machines capable of changing warfare forever..."
He gave a faint, self-deprecating smile.
"Would you have accepted it?"
Mulan's thoughts raced back to the person she had been then.
She had respected Mu Che.
She had admired his inventions.
But...
Would she have believed such an impossible story?
Would she have accepted that her husband wasn't simply gifted...
But possessed knowledge from another world?
She slowly lowered her head.
"...I..."
No answer came.
Because deep inside...
She already knew it.
She probably wouldn't have believed him.
Not completely.
Yun Che looked back toward the abandoned laboratory.
"I don't think this was about him not trusting you."
His voice was quiet.
"I think..."
"...he had no one he could burden with the truth."
He understood that loneliness better than anyone present.
There were some truths so extraordinary that speaking them aloud only invited disbelief, suspicion, or fear.
Some burdens became easier to carry alone.
The words struck Mulan harder than any accusation could have.
She looked once more at the abandoned laboratory.
For the first time, she didn't see a hidden place her husband had kept from her.
She saw the lonely refuge of a man who had carried a world of knowledge that no one around him could truly share.
The group continued deeper into the underground complex, passing row after row of towering missile silos. Each one was identical to the last, reinforced with thick steel blast doors and maintenance platforms that spiraled around their interiors. They were unmistakably designed to house weapons of enormous destructive power.
Yun Che's expression grew increasingly serious with every step.
The scale of the facility was staggering.
No ordinary workshop.
No hidden laboratory.
This was an underground missile complex.
His mind quickly pieced together everything he had learned over the past few days.
According to Jin Zhuo, Mu Che had repeatedly outwitted the great families that had sought to suppress the Jin Family. Through business deals, inventions, and carefully laid traps, he had extracted enormous sums of money from them—millions in gold that had seemingly vanished without anyone discovering where they had gone.
Now...
Yun Che believed he had his answer.
"So this is where it all went..."
He looked around the cavernous facility.
"He built this."
Retsu glanced at the endless launch tubes.
"...By himself?"
"Or with hired workers who never understood what they were building," Yun Che replied. "Compartmentalise the construction. One group excavates. Another pours concrete which a mixture of what he created. Another fabricates steel components. Nobody sees the entire project."
He nodded to himself.
"Only Mu Che knew what the finished product was supposed to become."
His thoughts drifted to the map of Xuanwu City's coastline.
Then everything clicked.
His eyes widened.
"...The beach."
Everyone looked toward him.
"This laboratory is not far from the beach."
His voice became grave.
"The exact coastline where the Wu Clan plans to launch their invasion."
Silence settled over the group.
"He wasn't building this for conquest..."
Yun Che looked toward the empty missile silos.
"He was preparing for the invasion."
Not one missile.
Not two.
An entire battery.
Enough to rain destruction upon an invading fleet before it could even reach the shore.
"...He planned this years in advance," Yun Che murmured.
They continued onward until the corridor opened into another chamber.
Unlike the previous rooms, this one resembled an enormous workshop.
Metal benches lined both sides of the room.
Precision tools lay scattered where someone had left them in a hurry.
At the center rested a large cylindrical object suspended by support frames.
It was incomplete.
The nose cone had yet to be attached, and portions of the guidance housing remained open, exposing intricate mechanical components inside.
Nemu immediately approached it.
"...May I?"
Yun Che nodded.
She carefully examined the object without touching anything unnecessarily. Her eyes traced the welds, stabilising fins, internal fuel compartments, and partially assembled propulsion section.
Several minutes passed.
Finally, she stepped back.
"It was never completed."
She looked at Yun Che.
"Or..."
"...its creator never had the chance to finish it."
No one spoke.
Around the workshop lay dozens of rolled paper scrolls.
Unlike cultivation manuals, each one contained carefully drawn diagrams, measurements, and calculations.
Yun Che picked one up.
English.
Every page.
Neat technical handwriting covered the parchment alongside engineering sketches.
Nemu accepted another scroll and quietly began reading.
"...These are blueprints."
She carefully unrolled another.
"And this one..."
Her expression became increasingly astonished.
"...Rocket propulsion."
Another scroll.
"Fuel mixture calculations."
Another.
"Stabilisation fins."
Another.
"Warhead assembly..."
She slowly lowered the document.
"It really is a missile."
Yun Che unfolded one of the larger blueprints across a nearby workbench.
Cross-sectional diagrams filled the page, detailing every internal component with painstaking precision.
"This isn't some crude explosive," he said quietly.
"It's a guided rocket."
He studied the warhead section.
"...Judging from the payload..."
He frowned.
"This thing could level an entire building."
The room fell deathly silent.
Nemu nodded.
"Potentially more."
She pointed to several handwritten calculations.
"The fragmentation radius alone would devastate a large area."
She paused before adding,
"Against cultivators below the Sky Profound Realm..."
She looked around the room.
"...Hundreds could be killed in a single strike."
No one said a word.
The implications were terrifying.
Mu Che hadn't been building weapons for personal protection.
He had been designing weapons capable of changing the very nature of warfare on the Profound Sky Continent.
Yun Che slowly rolled up the blueprint.
His gaze drifted once more toward the unfinished missile resting silently in its assembly cradle.
"...He was so close."
Whether he had run out of time...
Or whether something had interrupted him...
No one knew.
But standing inside the abandoned laboratory, surrounded by unfinished machines and scattered blueprints, they could almost picture the lone engineer working tirelessly through countless nights—driven by the desperate hope that, when the invasion finally came, these weapons would be ready to defend the city he had chosen to call home.
Yun Che carefully spread one of the larger blueprints across the workbench while Nemu stood beside him, comparing the handwritten calculations with the half-finished missile suspended in the assembly cradle.
Neither of them spoke for several minutes.
Finally, Nemu broke the silence.
"...Yuu-sama."
He nodded.
"I know."
The two exchanged a glance before arriving at the same conclusion.
"This isn't just any missile," Nemu said quietly. "Mu Che was attempting to recreate a V-2 rocket."
"The German ballistic rocket developed during the Second World War," Yun Che added. "One of the most advanced rocket systems of its era."
She pointed at the propulsion section.
"The liquid-fuel propulsion system..."
Then the guidance assembly.
"The gyroscopic stabilisation..."
Finally, the overall airframe.
"The dimensions are almost identical."
Yun Che folded his arms.
Around them, the rest of the group wandered through the enormous laboratory, their curiosity growing with every discovery.
Strange machines lined the walls.
Metal cabinets held unfamiliar tools.
Workbenches were covered with precision instruments unlike anything produced on the Profound Sky Continent.
Everything seemed impossibly advanced.
Nemu looked up from the blueprint.
"Please don't touch anything."
Her tone became noticeably firmer.
"Most of these components are beyond this world's technology."
She glanced toward the unfinished missile.
"If you accidentally tamper with the wrong mechanism..."
"...the payload alone could destroy this entire laboratory."
The warning immediately froze everyone in place.
No one moved another step.
Even the normally curious Mio quietly folded her hands behind her back.
Yun Che, meanwhile, continued counting the launch silos they had passed.
"...One..."
"...Two..."
His expression gradually became more serious.
"...Thirteen."
He slowly exhaled.
"Thirteen completed missiles."
His eyes shifted toward the unfinished rocket before them.
"And this..."
He rested a hand lightly on the assembly frame.
"...would have been the fourteenth."
Only this one remained unfinished.
Whether Mu Che had run out of time or been forced to abandon his work, no one could say.
Xue Yin slowly looked around the vast underground complex.
"I thought seeing your VTOL was already unbelievable."
Xue Ling nodded absentmindedly.
"...Compared to this..."
"...that almost seems ordinary."
The laboratory itself was an engineering marvel.
Fresh air continuously circulated through concealed ventilation ducts.
The temperature remained cool despite being buried beneath layers of earth.
There wasn't even a trace of stale air.
Nemu wandered toward a nearby control room.
Several minutes later—
"...Yuu-sama."
Her voice carried unmistakable surprise.
He walked over.
Behind a reinforced glass partition sat rows of electrical equipment.
Battery banks.
Power regulators.
Control panels.
Outside another observation window, sunlight poured into an angled shaft leading toward the surface.
Nemu examined the readouts.
"...Profound Energy?"
She looked genuinely impressed.
"The entire facility is powered by profound energy."
She pointed toward the battery arrays.
"And these batteries store excess electricity."
She looked around once more.
"...The lights..."
"...The ventilation..."
"...Everything is still operating after all this time."
Yun Che slowly shook his head.
His own technology largely existed because of the System.
Blueprints.
Fabrication.
Nanomachines.
Without it, many of his creations would have taken years to develop.
Mu Che...
Had no such advantage.
Or...
Did he?
The thought surfaced almost immediately.
"...Unless..."
Yun Che narrowed his eyes.
"...He had something similar."
Some form of assistance.
Another System.
An AI.
A mysterious inheritance.
Or perhaps...
Nothing at all.
Perhaps Mu Che had truly accomplished everything through his own intellect.
The possibility was somehow even more frightening.
"...Sugoi..."
Mio whispered in genuine admiration.
Her eyes wandered from machine to machine.
"He's amazing."
Retsu gave a slow nod.
"He may have lacked cultivation talent..."
She looked around the laboratory.
"...But he created all of this."
There was unmistakable respect in her voice.
Not for his strength.
But for his determination.
Against all odds, one man with a frail body had carved out an underground fortress of science beneath the very noses of every great family in Xuanwu City.
Mulan remained silent.
Her gaze lingered on the unfinished missile.
Unlike the others, she wasn't overwhelmed by the technology.
Her thoughts remained elsewhere.
She couldn't help wondering how many nights Mu Che had spent alone in this laboratory.
How many burdens he had carried without ever speaking of them.
A small part of her still ached.
Not because she believed he had intentionally excluded her...
But because she realised there had been an entire side of his life she had never known existed.
Nearby, Cang Yue and Lin Yueru quietly explored the laboratory together, carefully peering into open workstations and cabinets without daring to touch anything. Every shelf contained neatly labelled containers, precision tools, and unfamiliar metal parts arranged with almost obsessive organisation. Nothing appeared hastily abandoned; it looked as though its owner had intended to return the following day.
Lin Yueru slowly picked up a pair of protective goggles resting on a workbench before immediately setting them back down.
"...Wow."
She let out a helpless laugh.
"I thought I'd already seen everything after travelling with all of you."
Her gaze swept across the seemingly endless laboratory.
"Flying machines... firearms... drones..."
She pointed towards the missile resting in the assembly cradle.
"...Now this."
"I don't even know what to be surprised by anymore."
Cang Yue smiled faintly.
"Neither do I."
She gently ran her fingers across the polished metal workbench.
Her eyes became distant with remembrance.
"I thought no one could possibly create something more unbelievable."
She looked around the enormous underground complex.
"But seeing this..."
She slowly shook her head.
"His world truly is far beyond ours."
Her voice held no jealousy.
Only admiration.
"To us, profound energy can accomplish miracles."
She looked towards the ceiling where ventilation quietly circulated fresh air.
"But in his world..."
"...knowledge became their miracle."
Lin Yueru nodded.
Cang Yue smiled.
"Perhaps that's why Che'er always said that knowledge itself is a form of power."
The two women continued walking.
Every few metres another mystery awaited them.
One room contained dozens of precision measuring instruments whose purpose they couldn't even guess.
Another held shelves filled with carefully machined metal gears of every imaginable size.
One chamber appeared dedicated entirely to chemical storage, each container bearing warning labels written in English.
Neither dared step inside.
Elsewhere, Qingyue stood before the unfinished missile.
Her eyes slowly travelled along its sleek metallic body before shifting towards Yun Che and Nemu.
The contrast was striking.
Everyone else had entered this laboratory with expressions of shock and disbelief.
Yet Yun Che and Nemu...
They behaved as though they were simply inspecting another engineering workshop.
They asked logical questions.
Examined construction methods.
Identified propulsion systems.
Discussed manufacturing techniques.
Instead of being overwhelmed...
They understood it.
Qingyue lowered her gaze.
I'm considered a genius within the sect...
But standing here...
She looked back at the pair.
Compared to them...
I feel like a child listening to masters discuss subjects beyond my comprehension.
Knowledge.
Not cultivation.
That was the gap separating them.
Nearby, Little Fairy slowly circled one of the enormous missile silos.
She reached out but stopped herself before touching the cold steel.
"...How many secrets did Mu Che hide?"
Even someone as composed as she couldn't hide the astonishment in her voice.
Chu Yueli quietly nodded.
"I always thought his greatest talent was inventing useful tools."
She looked around the immense facility.
"I never imagined..."
"...this was what he had truly been working on."
She let out a slow breath.
"If this place had remained hidden for another decade..."
"I don't even know what he might have created."
Back inside the workshop, Nemu had already become completely absorbed in the blueprints.
One scroll after another was spread neatly across the central table.
She compared handwritten calculations with the unfinished missile, occasionally making notes in a small notebook she had retrieved from her pocket.
"...Interesting."
Yun Che walked over.
"What did you find?"
Nemu pointed at several diagrams.
"The design faithfully follows the German V-2."
She traced the propulsion section.
"The engine is surprisingly accurate."
Then she pointed towards the guidance assembly.
"But..."
She frowned.
"It also inherits the V-2's greatest weakness."
Yun Che nodded almost immediately.
"No terminal guidance."
"Hai."
Nemu continued.
"Once launched, the missile follows a pre-calculated ballistic trajectory."
She lightly tapped the blueprint.
"It cannot actively correct itself toward a moving target."
"So if the enemy fleet changes course..."
"...accuracy drops significantly."
She turned another page.
"Against cities..."
"...acceptable."
"Against moving ships..."
"Far less effective."
Yun Che folded his arms.
"Which means Mu Che either accepted that limitation..."
"...or intended to solve it later."
Nemu's eyes brightened.
"I believe the latter."
She pointed towards an unfinished section of the blueprint.
"There are blank spaces here."
Several annotations simply ended midway through a sentence.
Entire diagrams had been outlined but never completed.
"He was redesigning the guidance system."
Her finger moved to another sheet covered with equations.
"Possibly planning to add active course correction."
Yun Che looked over the calculations.
"...Gyroscopic refinement..."
"...Control surfaces..."
"...Signal processing..."
A small smile appeared on his face.
"He'd already identified the problem."
Nemu nodded.
"And if given enough time..."
"I believe he would have solved it."
She looked around the workshop.
"I can finish what he started."
Everyone turned towards her.
Nemu spoke with quiet confidence.
"With modern control algorithms, improved inertial navigation, and a guidance package..."
She glanced at Yun Che.
"...we can turn this into a true guided missile."
Yun Che smiled.
"I was thinking the same thing."
He looked once more at the unfinished V-2 resting silently in its cradle.
"Mu Che built the foundation."
He placed a hand gently against its unfinished fuselage.
"We'll complete the next chapter."
While the others continued exploring the underground complex, Nemu carefully gathered every blueprint scattered across the workshop.
She treated each scroll as though it were an irreplaceable historical document.
Some were complete.
Others were only rough sketches.
Several consisted of nothing more than calculations hastily scribbled into the margins before being abandoned midway through a thought.
One after another, she arranged them neatly across the workbench.
"...There's more."
Retsu walked over.
"More missiles?"
Nemu slowly shook her head.
"No..."
She unrolled another scroll.
"These aren't related to the V-2 project."
The blueprint depicted an unfamiliar vehicle with tracked treads and a rotating turret.
Yun Che glanced at it from across the room.
"...A tank?"
Nemu nodded.
"It appears to be."
Another blueprint revealed a compact engine.
Another described an electrical generator several times more efficient than the one currently powering the facility.
There were communication systems.
Portable radios.
Improved firearms.
Early radar concepts.
Industrial manufacturing equipment.
Even rough plans for expanding the underground complex itself.
Each project was more ambitious than the last.
"...These were all future projects," Nemu murmured.
Her fingers paused over a page whose title ended abruptly halfway through a sentence.
"He never finished writing this."
Mio leaned over curiously.
"So..."
"He planned to build all of these?"
"I believe so."
Nemu carefully stacked the documents into separate piles.
"Completed."
"In development."
"Concept only."
The "Concept" pile continued growing.
She eventually let out a quiet sigh.
"...If he had lived..."
No one answered.
They all understood the unspoken ending.
If Mu Che had survived...
This laboratory would likely have become something far greater than a hidden missile complex.
It could have become the birthplace of an entirely new technological era.
"Just record everything.."
"Hai.." Nemu nodded.
Meanwhile...
Yun Che had quietly slipped away.
Unlike the others, his attention remained fixed on two things.
The faint signal detected by the System.
And the trail of dried blood only visible through Eagle Vision.
The crimson trail continued deeper into the facility.
It crossed intersections.
Passed sealed storage rooms.
Descended another flight of reinforced steel stairs.
Unlike the workshop, this section felt different.
Quieter.
More isolated.
The walls became thicker.
Security doors appeared at regular intervals.
Each one required electronic access.
"...Whatever was down here..."
Yun Che muttered.
"...Mu Che considered it even more important than the missile program."
The blood trail continued without interruption.
Whoever had been bleeding had clearly been injured badly.
Yet...
There were no signs of struggle.
Only a lonely trail disappearing into the depths of the facility.
Eventually...
The corridor came to an end.
Before him stood another reinforced metallic door.
It was noticeably heavier than every door they had passed so far.
The hinges alone were as thick as his forearm.
A red warning light still glowed faintly above the entrance, somehow drawing power after all these years.
Mounted beside the door was another electronic keypad.
Unlike the previous one, this keypad showed almost no signs of wear.
Yun Che slowly approached.
His Eagle Vision swept over it.
He examined every button.
Every scratch.
Every fingerprint left long ago.
Then he looked back at the dried blood.
The trail ended here.
Not beyond the door.
Directly in front of it.
His expression slowly hardened.
"...This is where it happened."
Behind him, the others gradually caught up.
Nemu tucked the recovered blueprints safely under one arm before looking at the imposing door.
"...Another password?"
Yun Che gave a slow nod.
"But this one..."
He glanced once more at the dried blood pooled faintly before the keypad.
Yun Che studied the keypad in silence.
The dried blood beneath it had long since turned dark brown, preserved by the laboratory's climate control.
He rested a finger on the keys.
"...Let's see."
If Mu Che had designed the entrance security...
He likely had habits.
People often reused important numbers, especially when they never expected anyone else to discover their hidden sanctuary.
Yun Che entered the same six digits.
3...
1...
4...
1...
5...
9...
A brief pause followed.
Then—
Beep.
Heavy locking mechanisms disengaged one after another.
Thunk... Thunk... Thunk...
The reinforced door slowly slid sideways with a prolonged metallic hiss.
"...It worked."
He glanced over his shoulder.
The others were still gathered around the workshop. Nemu was carefully cataloguing Mu Che's blueprints while the rest listened to her explanations.
None of them noticed the door opening.
Yun Che quietly stepped inside alone.
The door slid shut behind him.
Darkness.
Absolute darkness greeted him.
The air inside felt different from the rest of the facility.
Still.
Silent.
Untouched.
His hand found the switch panel beside the entrance.
Click.
One row of ceiling lights flickered to life.
Then another.
And another.
Until the entire room was illuminated in a soft white glow.
It wasn't another laboratory.
Nor a weapons depot.
It was...
A living space.
Simple.
Modest.
A neatly made bed stood against one wall.
A wardrobe occupied another.
Everything remained exactly as though its owner had simply stepped out for a moment.
Yet...
No one had returned.
Yun Che walked further inside.
His footsteps echoed softly across the polished floor.
At the centre of the room stood a sturdy office desk.
Scrolls and papers lay scattered across its surface.
Some contained engineering sketches.
Others were filled with calculations.
Yun Che stopped beside the desk.
His gaze slowly shifted beyond it.
Towards the chair.
There...
Sat a lone skeletal figure.
Time had reduced the body to little more than bleached bone, but the clothes remained remarkably well preserved by the controlled environment.
One hand still rested on the armrest.
The other had fallen limply beside the chair.
The skull was slightly lowered.
Almost as though its owner had simply fallen asleep while thinking.
Yun Che stood motionless.
The dried blood trail.
The abandoned missile.
The unfinished blueprints.
Everything suddenly made sense.
His voice barely rose above a whisper.
"...This is where you were."
His eyes swept around the quiet room.
"...All by yourself."
No final companions.
No family.
No one to witness his last moments.
Only silence...
Inside the laboratory he had built with his own hands.
Yun Che slowly walked past the desk until he stood before the remains.
For several long moments...
He simply looked at the man.
Not as a legendary inventor.
Not as the mysterious Mu Che.
But as someone who had once come from a world much like his own.
Someone who had carried knowledge no one around him could truly understand.
Someone who had fought alone for years.
Someone who had died alone.
Yun Che slowly lowered his head.
There was no grand speech.
No dramatic declaration.
Only quiet respect between two people separated by time, yet connected by the same impossible circumstance.
"...Rest in peace..."
He closed his eyes briefly.
"...Mu Che."
The room remained silent.
Only the gentle hum of the laboratory's ventilation answered him, faithfully continuing its duty long after its creator had drawn his final breath.
===========
[Ding... Signal is closer.]
===========
Yun Che remained standing before Mu Che's remains for a long moment before the System's faint guidance pulsed once again.
A subtle marker appeared at the edge of his vision.
Not towards the desk.
Not towards the bookshelves.
But...
Behind the skeletal figure.
His eyes followed the invisible indicator until they settled upon another section of the wall.
"...There's another compartment."
Hidden almost seamlessly within the alloy panels was yet another electronic keypad.
Smaller than the others.
Far more discreet.
Almost as if Mu Che had intended this one to remain undiscovered even by anyone who managed to reach his private quarters.
Yun Che stared at it for a few seconds.
"...Let's hope you were consistent."
He entered the familiar sequence.
3.
1.
4.
1.
5.
9.
Beep.
A quiet mechanical click echoed from inside the wall.
The panel slowly slid aside.
Yun Che instinctively stepped forward.
Then...
His pupils contracted.
"...What in the...?"
Resting upon a small pedestal inside the concealed compartment was a golden sphere.
Similar the size of a golf ball.
Its polished surface shimmered beneath the laboratory lights.
Elegant engravings flowed across its exterior like living lines.
He knew that design.
He knew that shape.
His breathing slowed.
"...Another Apple of Eden?"
It looked almost identical to the one he had recovered from Huan Xuyi's tomb.
Only smaller compared to it.
There was no mistaking it.
The unmistakable craftsmanship.
The impossible material.
The faint aura that seemed to bend perception itself.
For several seconds, Yun Che simply stared.
"So..."
He whispered.
"All this time..."
"...Mu Che possessed a Piece of Eden."
Everything suddenly fit together.
His astonishing technological achievements.
His impossible understanding.
His ability to construct an underground complex decades ahead of its time.
His rapid progress despite lacking the industrial base of a modern civilization.
Perhaps...
The Apple had guided him.
Perhaps it had preserved knowledge.
Perhaps it had simply given him access to information beyond this world's understanding.
Whatever the truth...
It explained far more than coincidence ever could.
Then another thought surfaced.
Yun Che immediately activated the System's detection interface.
If there was another Piece of Eden...
Its network should update.
A translucent map unfolded before his eyes.
Nine faint markers appeared.
He counted automatically.
"...One..."
"...Two..."
"...Three..."
His expression slowly changed.
"...Seven?"
The display showed seven distant signals.
Scattered across the world.
Each isolated from the others.
He frowned.
"...That's impossible."
His gaze shifted between the hidden Apple and the System interface.
"The network still only reports seven external signals."
"Two is still missing."
He looked back at the orb.
"If this were one of the missing Pieces..."
"...the count should have changed."
It hadn't.
Not even slightly.
Yun Che narrowed his eyes.
"...No."
His mind raced through every possibility.
"A Piece of Eden can't mask its own signal."
That much the System had confirmed repeatedly.
Each Piece constantly resonated with the others.
More likely had an Isu construct inside it like the Isu Ares inhabit Xuyi's body.
That resonance was exactly how the System had guided him to Huan Xuyi's tomb in the first place.
If this truly were another Piece of Eden...
The System should have detected it long before he entered the room.
Yet...
It hadn't.
Not once.
Only after physically opening the hidden compartment had the object become visible.
Yun Che slowly reached out, stopping just short of touching the golden sphere.
"...Then what are you?"
An imitation?
A prototype?
A storage vessel?
Or something even stranger?
His gaze shifted back to the display.
Seven signals.
Not eight.
Not nine.
Just seven.
Which meant the object before him existed entirely outside the System's detection network.
For the first time since entering the laboratory...
Yun Che felt genuinely unsettled.
Because whatever rested inside Mu Che's hidden compartment resembled an Apple of Eden perfectly...
Yet somehow...
It did not behave like one at all.
Yun Che kept his hand suspended just above the golden sphere.
The familiar metallic sheen.
The intricate engravings.
Even the weight of its presence felt nearly identical to the Apple of Eden he had recovered from Huan Xuyi's tomb.
Yet the System insisted otherwise.
His brow furrowed.
"...System."
He spoke silently.
"Is this one of the two missing Pieces of Eden?"
A brief pause followed before the familiar voice answered.
=============
[Ding... Negative.]
[This object is not one of the nine Pieces of Eden that descended during the era of Huan Xuyi.]
=============
Yun Che's eyes narrowed.
"...Then what is this?"
For the first time in a long while—
The System hesitated.
Several seconds passed.
Then...
=============
[Unknown Piece of Eden.]
=============
Yun Che blinked.
"...Unknown?"
He frowned.
"...How can it be unknown?"
The System had always classified the relics with absolute certainty.
Yet now...
Even it appeared unable to properly identify the object.
No additional explanation came.
Only silence.
Yun Che slowly looked back towards the golden orb.
His thoughts rapidly connected one possibility after another.
"...Then..."
His breathing slowed.
"...Could Mu Che have brought it here?"
The idea sounded absurd.
Yet...
It explained everything.
If Mu Che truly originated from a world similar to his own—
Perhaps even the same Earth—
Then this Apple may never have belonged to the Profound Sky Continent at all.
Perhaps it had existed long before either of them had crossed worlds.
"...The twenty-first century..."
"...Or perhaps even the twenty-second."
He spoke quietly to himself.
"If he discovered it there..."
"...and somehow crossed into this world while carrying it..."
His gaze remained fixed upon the orb.
"...Then he really did come from my world."
Not merely a similar civilization.
Not another technologically advanced realm.
Earth.
Only...
From an unknown point in history.
Earlier?
Later?
Yun Che couldn't tell.
He carefully examined the Apple once more.
Unlike Huan Xuyi's artifact...
This one felt...
Quiet.
There was no lingering consciousness.
No hidden projection.
No ancient personality waiting to awaken.
No holographic entity sealed within.
It was simply...
An empty vessel.
Or perhaps...
A dormant one.
"...No guardian..."
Yun Che murmured.
"No stored consciousness."
The System immediately responded.
================
[Confirmed.]
[No detectable Isu consciousness is present.]
[No cognitive imprint detected.]
[Object possesses substantial residual energy.]
================
Residual energy.
That single phrase caught Yun Che's attention.
"So it's still functional..."
The System answered almost immediately.
=============
[Confirmed.]
[Energy output significantly exceeds standard Pieces of Eden.]
=============
Yun Che's pupils contracted.
"...Exceeds?"
That shouldn't have been possible.
The nine Pieces recovered from Huan Xuyi's era were already among the most powerful artifacts the System had catalogued.
Yet this empty Apple...
Contained even greater reserves of energy.
He slowly withdrew his hand.
His heartbeat had unconsciously quickened.
Mu Che hadn't merely possessed advanced scientific knowledge.
He had also carried an artifact that even the System couldn't fully classify.
A Piece of Eden...
Yet not one recorded in the world's history.
Yun Che looked back at Mu Che's skeletal remains.
His expression became increasingly thoughtful.
"...Just who were you...?"
A man from Earth.
An engineer.
A genius.
The builder of an underground missile complex.
And now...
The owner of an unknown Apple of Eden that existed completely outside the System's records.
The deeper Yun Che dug into Mu Che's past...
The more impossible the man became.
For the first time since arriving in this world, Yun Che found himself wondering whether he and Mu Che had truly shared the same origin—
Or whether Mu Che had come from an Earth far beyond even the one Yun Che remembered.
Yun Che stared at the golden sphere for several more seconds.
It was silent.
Motionless.
No projections.
No hidden voice.
Nothing like the Apple of Eden from Huan Xuyi's tomb.
"...Let's see what makes you different."
He slowly extended his right hand.
The instant his fingertips brushed the polished surface—
BZZZZT—!
The Apple exploded with brilliant golden light.
"Wha—?!"
Yun Che instinctively tried to pull away.
Too late.
The entire chamber shook violently as countless golden lines spread across the sphere's surface like living circuitry.
The dormant artifact awakened.
A pillar of golden light erupted from its core.
The hidden compartment vanished beneath the radiance.
The office.
The skeleton.
The laboratory.
Everything disappeared behind an overwhelming sea of gold.
Outside the room...
Nothing happened.
The laboratory remained perfectly quiet.
The others continued examining Mu Che's workshop, completely unaware that the sealed chamber had just been engulfed by a phenomenon beyond their perception.