Chapter 165: Departure

"Yin-Yang Symbol Diagram?"

Zheng Fa and Tang Lingwumin exchanged a glance, both seeing a look of bewilderment on the other's face.

Wait, shouldn't your Great Dream Symbol's effect have worn off by now?

The old white-haired man saw their expressions, snorted, sat down on the chair, stretched his legs outward, and the entire chair tipped backward, resting only on its two rear legs as he swayed lazily in it, chin tilted skyward—

Said nothing, yet seemed to have said all his boastful words already.

"From now on, our sect's scriptures must record clearly: this True Person awoke to the Dao in a dream, comprehending the origin of Yin and Yang."

"... randpa Bai!"

Tang Lingwumin, seeing he was trying to tease them, whispered in a soft, playful scold.

The old white-haired man glanced at her, then waved both hands toward them.

"Want to know?"

"Mm!"

"Give me your hands."

Tang Lingwumin looked slightly confused but obediently extended her right hand.

The old white-haired man turned to Zheng Fa and said: "Yours too."

Zheng Fa was also a bit puzzled, but extended his right hand as well.

"Switch to your left hand."

The old white-haired man pressed Zheng Fa's left hand against Tang Lingwumin's right hand, palm to palm, finger to finger, with not a single gap between them.

Tang Lingwumin's face flushed instantly, her earlobes seeming to burn.

But Zheng Fa looked as if he'd just understood something.

"This… is Yin and Yang."

The old white-haired man spoke in the tone of someone giving a speech on a podium in his dream.

"... andedness?"

"Exactly!"

The old white-haired man released their hands and looked at Zheng Fa: "The most obvious distinction of the Yin-Yang Symbol Diagram is handedness."

Zheng Fa recalled the Yin-Yang Symbol Diagram in his mind.

It really was!

The old white-haired man muttered: "I knew about this too, but I never studied it before… If I hadn't seen my own hands while staring at those diagrams in my dream, I'd never have thought of this."

Zheng Fa nodded slightly.

Handedness isn't a particularly important concept in topology—or rather, Zheng Fa had rarely encountered it, only seeing it mentioned in knot theory.

"Is the Yin-Yang Symbol Diagram really this simple?"

Tang Lingwumin, standing nearby, voiced her own doubt.

Zheng Fa understood why she called it simple—handedness is an intuitive concept.

Simply put, your left and right hands appear identical, yet in three-dimensional space, no matter how you translate or rotate your left hand, it can never become your right hand.

This kind of spatial configuration is called handedness.

Naturally, handedness can be divided into left-handedness and right-handedness.

Zheng Fa recalled: the Yang Symbol Diagram corresponded to left-handedness, while the Yin Symbol Diagram corresponded to right-handedness.

"Not simple," Zheng Fa shook his head. "This is merely the spatial relationship of the diagram…"

The old white-haired man smiled faintly and nodded: "Correct. This is only the surface—handedness isn't studied much in our mathematics. From what I know, biology and chemistry study it the most."

"Chiral molecules exhibit different properties."

"I don't know if they've explained why, but I know this: we don't understand why the Yin-Yang Symbol Diagrams behave differently due to handedness."

Zheng Fa agreed: "And there's another issue…"

He and the old white-haired man exchanged a glance, speaking in unison: "Yin-Yang mutual generation."

At this, the old white-haired man grimaced, as if his head ached: "You see, chiral objects cannot be superimposed in three-dimensional space, so you can say they're entirely different things—but Yin-Yang mutual generation… that implies they're connected…"

…

Xuanwei Realm.

Zheng Fa sat on the bed, his spiritual sense gazing inward at his Yuanfu Dao Base.

The Yuanfu Dao Base remained as two lotus flowers joined at their bases.

Handedness configuration.

Yin-Yang mutual generation.

Zheng Fa willed it, and the lotus platform with its downward-facing stamens cracked gently and vanished.

Yet the next moment, golden threads slowly sprouted from the base of the remaining lotus platform, and the lotus platform began to reappear.

This was what Zhang Shijie had called Yin-Yang mutual generation.

But Zheng Fa widened his eyes, staring at the newly reappeared lotus platform.

Previously, he'd assumed these golden threads were the roots of the lotus platform.

But now he saw clearly: these golden threads were fine arcs—more like ripples spreading outward from the base of the lotus platform!

"Mirror image?"

An idea arose in Zheng Fa's mind.

The mirror image of your right hand is your left hand.

So the mirror image of the Yang Symbol is the Yin Symbol.

The essence of Yin-Yang mutual generation—is it mutual mirroring?

Or is the lower lotus platform merely the reflection of the upper one?

…

Zheng Fa currently lacked the ability to verify this hypothesis—Zhang Shijie wasn't here, and he truly had no way to test it.

Thinking of Zhang Shijie, he picked up the Xuanlei Stone and began cultivating the Five Thunder Body Scripture.

His bones were now coated with a faint golden membrane—the mark of his Five Thunder Body cultivation reaching peak bone forging.

Now, he was cultivating the fourth layer of the Five Thunder Body Scripture—blood replacement.

This was the final layer before Heavenly Thunder Body Tempering.

And his final preparation before entering the Lei Chi.

From the Xuanlei Stone, lightning flowed like water into his body, seeping through his skin, penetrating his muscles, and finally drilling into his bones, churning violently within his bone marrow.

Excruciating pain!

Zheng Fa had endured much hardship as a child.

He'd fought with village boys.

He'd been cut by sickles and hoes.

He'd even experienced near-death moments—

But never once had he felt pain like this!

Probably because bone marrow contains many nerves, making the agony intensely clear.

He curled into a ball, lying on the bed, sweat beading on his forehead and falling with every tremor.

He'd tried this before, and each time, before beginning, he thought he'd grown used to it.

Yet each time, he felt as if standing on the edge of an abyss, utterly hopeless.

In his hand, the half jade pendant was crushed tightly, as if about to shatter.

…

Two or three zhang from Pang Shu's hall, loud shouts from inside pierced Zheng Fa's ears.

"Master! Don't charge!"

"Save me, save me!" That was Pang Shu's voice: "Someone, give me a Blood-Stopping Symbol!"

"Master, surrender! You're surrounded by our people!"

"..."

Zheng Fa shook his head.

This was Pang Shu again, gathering his disciples for a gaming session.

He never expected the first internet addict in Jiushan Sect—wait, the oldest one—was Pang Shu.

According to Zheng Fa, Pang Shu had specifically asked the Sect Master for numerous Great Dao Struggle Immortal symbols and arrays before coming to Lei Chi.

But Pang Shu never cheated in games.

He always sealed his spiritual sense and spiritual power, playing only with Qi Refining realm cultivation.

He never cursed when he lost.

His temper was actually good.

But he had one problem—he was too reckless.

Zheng Fa now strongly suspected that his own master's script, "Saving Little Cultivator Pang Qian," had a real-life prototype.

Thinking of how Pang Shu taught him now—

Zheng Fa always felt Pang Shu was searching in games for the boy he once was…

Pushing aside these scattered thoughts, Zheng Fa gently knocked on the hall door.

"Enter!"

Zheng Fa stepped inside, and Master Pang waved his hand—the illusion of "The Great Dao's Struggle for Immortality" vanished instantly.

Several senior brothers exchanged glances, as if all of them were sneering.

Is this… throwing a tantrum because you can't win?

"Ahem." Seeing Zheng Fa's expression of sudden insight, Master Pang cleared his throat and asked, "What do you want?"

"I've come to ask Master for information about Lei Chi."

"You're planning to enter Lei Chi? Have you completed the fourth layer of the Five Thunder Body?"

Master Pang froze, slowly sat up, and his gaze turned serious.

"Yes!"

"..." Master Pang stared at him for a long time, saying nothing, as if lost in thought.

"Master?"

"Before your master came, he told me," Master Pang suddenly changed the subject. "He said your biggest obstacle to completing the fourth layer of the Five Thunder Body isn't resources—it's endurance."

"..."

"He said, each time he changed his blood, he waited ten days or even half a month before doing it again."

At Master Pang's words, the senior brothers in the hall all turned to look at Zheng Fa.

Their gazes varied.

"He told me it was excruciatingly painful—each blood change felt like being flayed alive, piece by piece, from within," Master Pang shook his head. "So even though he never lacked Black Thunder Stones, it still took him half a year to complete the fourth layer's blood transformation."

"And you… completed it in half a month. Why so desperate?"

Zheng Fa lowered his head. "Sister Zhang is alive, but she's been missing—her situation can only be worse than we imagine."

Master Pang fell silent again.

"... ister Zhang didn't misjudge you." Master Pang shook his head, flicked his hand, and several jade cylinders floated to Zheng Fa's Mianqian. "Here's the information on Lei Chi from the marketplace, and some accounts from our Jiushan Sect disciples. Take them."

Zheng Fa gathered the jade cylinders, bowed to Master Pang, and turned to leave the hall.

Watching his retreating figure, Master Pang's gaze grew distant, lost in thought.

"Master, still playing?"

Seeing him remain silent, a disciple beside him whispered.

"Play, play, play! All you know is play!" Master Pang suddenly exploded. "Look at Zheng Fa—he cultivates this hard. Why do you only know how to play?"

"..."

"He endures piercing pain for Sister Zhang, pushing himself to the limit. What about you? If I disappeared, could you do the same?"

"... isciples would gladly face fire and water..."

The disciples chorused.

"Get out! Do you think I don't know you?"

Master Pang snorted, waved his hand forward, and the disciples were flung out of the hall.

When he looked up again, the hall doors were tightly shut.

The disciples glanced at each other, none daring to speak, and left together.

Only when they were far away did one disciple voice his doubt:

"Playing 'The Great Dao's Struggle for Immortality'... wasn't that Master's own setup? We couldn't even refuse!"

"Master is jealous of Sister Zhang."

One disciple's remark earned nods from the others.

"True—we can't match Brother Zheng," one said, dejected.

"We can't match Zheng Fa—but can Master match Sister Zhang?"

"Huh?"

This made the others question it.

Sister Zhang might be powerful, but their Master was a Nascent Soul True Person.

"Just imagine—if Sister Zhang had Master's face, would Zheng Fa rush to save her so desperately?"

"..."

"Would you?"

"... ven though she's our Master, Sister Zhang never got along well with us..." one senior brother spoke up. "But that's no excuse to disrespect her like this."