“Mr. Song, there’s something you may not know...”

Advisor Zhang leaned closer to Song You and whispered, “The enemy we’re facing is the eastern eight tribes of the grasslands, under the command of the northern Right Wolf King. Among his subordinates is a strategist who has a peculiar hobby—he enjoys collecting severed hands, feet, skulls, or other body parts from his enemies as trophies and often plays with them.

“Previously, we devised a meticulous plan and sent a pair of Mr. Yin’s ears to his tent.”

“Does that mean the movements of the northern Right Wolf King’s army are entirely under your control?” Song You asked.

“It’s not quite that effective,” Advisor Zhang replied. “First, since the ears are in that strategist’s tent, we can only hear what’s said within it. Most of the time, important discussions among the army of the northern frontier take place in the Right Wolf King’s main tent, and this strategist is only one of many under the Wolf King.

“Second, the ears are usually kept in a box. Whether or not we can hear anything clearly depends entirely on chance.”

“I see.”

“Still, any bit of information we can gather is something. It’s better than nothing,” Advisor Zhang added.

“Indeed,” Song You agreed, falling silent as he turned his attention to Yin Wenxing.

He had moved to a corner of the training hall, hands covering his ears and bending slightly as he listened intently. After a while, his voice came through, “They’re discussing Mr. Song...”

“Who’s discussing him? And what are they saying about him?” Advisor Zhang immediately leaned in and asked in a hushed tone.

“The Right Wolf King’s other strategist went to speak with him. They mentioned the stone giant from this afternoon and speculated that a powerful cultivator had come to aid our army...”

“And what else?”

“I couldn’t hear clearly. The ears are kept in a box, so the sound is muffled and unclear. They were also walking around while talking.”

“Focus and listen carefully,” Advisor Zhang instructed.

Everyone present fell silent again, not daring to speak. For a moment, the training hall was so quiet that even the sound of a pin dropping could be heard.

The atmosphere felt remarkably strange to Song You.

The Lady Calico also widened her eyes, her pupils darting left and right in curiosity. Even a child would find such a scene fascinating.

After a while, Yin Wenxing’s voice came through again, “It seems they’re planning to send that elusive demon into the city to test Mr. Song.”

“A nighttime attack on Mr. Song?”

“It seems so… Ah, no, wait!”

“What is it?”

“They’re planning to let the demon in to cause some chaos and secretly observe what Mr. Song looks like and what abilities he has.”

“Keep listening.”

“They’ve left the main tent...” Yin Wenxing removed his hands from his ears, indicating that he could no longer hear anything.

The group collectively exhaled, as if they had only just begun breathing again.

General Chen broke the silence, saying, “If that demon comes for Mr. Song, that would actually be a simple matter.”

“What kind of demon is it?” Song You asked.

“It’s a demon in the northern frontier known as 'Bolai.' We’re not sure of its origins,” General Chen explained. “As for how strong Bolai is, it’s not particularly formidable. It’s just unusually strong and has claws sharp enough to disembowel someone.

“The officers in the army skilled at breaking through enemy formations might not be able to defeat him barehanded, but if fully armored and equipped with suitable weapons, they wouldn’t necessarily fear him either.

“However, this Bolai possessed an almost supernatural ability to appear and vanish unpredictably. His movements were swift, making it impossible to know where he would emerge or disappear next, leaving others unable to guard against him.”

“Bolai has been a huge headache for us,” Advisor Zhang added with a sigh. “Many of our officers have died at its hands in their dreams, and the deaths are always horrific. On top of that, it has brought plagues or other demonic curses into the city. Even now, many officers and soldiers are suffering from the diseases it spread.

“These days, no one dares sleep deeply; they have to take turns standing watch. Even so, there are still occasional casualties. Whenever it kills, it uses the victim’s own weapon to pin them to the ground. Sometimes it even tears off pieces to devour. Its cruelty has left the entire city in terror.”

Such was the power of a demon on the battlefield.

Even a demon with unremarkable combat strength possesses abilities utterly distinct from those of ordinary humans, often capable of performing terrifying acts. The psychological impact such creatures have on soldiers can rival that of an approaching great enemy army.

After listening, Song You thought for a moment before asking, “Could it be Wall-Passing Technique or Earth-Burrowing Method?”

“At first, we suspected it might be one of those techniques,” Advisor Zhang replied, “but we have individuals in the army who are knowledgeable about Daoist arts. We've devised countermeasures and tests. While such methods might work once or twice, repeated encounters proved it wasn't a Wall-Passing Technique or Earth-Burrowing Method.”

He furrowed his brow. “It seems to appear out of nowhere and disappear just as suddenly.”

“Appear out of nowhere and disappear just as suddenly?”

“That’s what we’ve concluded after prolonged engagements and observation,” Advisor Zhang explained. “Mr. Yin occasionally picks up fragments of conversations that, while not conclusive, do lend some support to this theory.”

“Has anyone seen it arrive?” Song You asked.

“A general once caught sight of it, claiming it materialized out of thin air.”

“Materialized out of thin air,” Song You repeated, pausing briefly before asking, “And has anyone seen it leave?”

“No, that hasn’t happened.”

“...”

Song You frowned slightly.

Seeing his expression, Advisor Zhang pondered for a moment and seemed surprised. He asked, “Mr. Song, could it be that you know the origins of this technique?”

“I know of a technique that bears some similarities, but it hasn’t been seen for many years. I can’t say for certain if this is the same.”

“Oh?”

Everyone was instantly astonished upon hearing this.

The myriad techniques of the world were often mysterious and difficult to grasp. The most challenging aspect of dealing with such techniques was the lack of understanding about them. Sometimes, once their origins were known, countering them became relatively straightforward.

Take, for example, the Paper Yaksha.

On the battlefield, without knowledge of its weaknesses, it could be as formidable as a fierce general. Encountering it unexpectedly in the

jianghu

would likely leave most people at a loss. But if one were already aware and had prepared in advance, it could easily be dealt with by a simple fire, reducing it to ashes.

Or consider the Earth-Burrowing Method.

By exposing its method and unsettling the user’s focus, the technique could be disrupted.

Understanding the origins of a technique might very well lead to a means of countering it.

The group immediately grew eager and began asking anxiously.

“Please, sir, tell us!”

“Have you heard of Phantom Trace?”

“Phantom Trace?”

“Precisely,” Song You confirmed.

Song You slowly explained to them, “This is an advanced Daoist technique. In ancient times, people still practiced it, but it has not been seen for many years. As its name suggests, Phantom Trace allows the user to appear and disappear without a trace.

“A novice can pass through a wall or a door, and the more profound one’s mastery, the greater the distance. It is said that in ancient times, some remarkable practitioners could traverse the ends of the earth in an instant. This is likely an exaggeration, but traveling a hundred li should be achievable.”

This technique was also documented in Hidden Dragon Temple’s collection.

However, as Song You mentioned, after ancient times, it was rarely practiced.

The main reason was similar to that of the arts of telekinesis: it was extraordinarily difficult to learn and required a tremendous amount of time. But Phantom Trace was far more demanding, often requiring several decades, if not centuries, to master.

To practice this technique, one had to retreat into solitary seclusion. It was said that even for a beginner to get started, they would need to train alone in a pitch-dark cave for nine days nine times, a total of eighty-one days. After completing this, they had to rest for at least one hundred days before repeating the process seven days seven times, a total of forty-nine times.

These symbolic numbers—nine days nine times and seven days seven times—were likely chosen for their auspicious sound rather than strict accuracy, though the actual time required is roughly similar. Individual aptitude might cause slight variations, but overall, each cycle would take roughly six months. Entering just the introductory stage would require over twenty years.

Moreover, before beginning this technique, practitioners needed a high level of foundational Daoist cultivation; otherwise, it would be nearly impossible to endure months-long retreats in isolation.

During the practice period, no other activities could be undertaken. And this was just to reach the entry level.

Thus, it was not that modern practitioners could not learn this technique, but in ancient times, when longevity was easier to attain, people had ample time to dedicate to such practices. In the current era, with longevity so elusive, fewer people had the time or inclination to pursue it.

To reach the entry level and merely gain the ability to pass through a wall or a door, one would spend over twenty years—a dubious trade-off.

To reach a higher level of mastery? A single lifetime would likely prove too short.

At present, only demons and spirits might still possess the capability to practice such techniques.

However, this was merely because the shift in the Heavenly Dao had only recently begun. Human cultivators, being the most prosperous, were the first to face its effects, while the turn for spirits and demons had yet to fully come—they were still waiting in line, so to speak.

At that moment, Song You continued, “This Phantom Trace technique is a legitimate Daoist art from ancient Great Yan. But as the general mentioned, these demons all seem to have emerged from Zhaoye City. As for the deity originally occupying Zhaoye City, it was a god once worshipped by one of the southern tribes of the eighteen tribes in the northern grassland. Why would this deity be in Zhaoye City?”

“It’s possible that demons and ghosts have no allegiance to nations or tribes. This Bolai might have originally been a demon within Great Yan’s northern borders but was drawn to Zhaoye City by the demon king’s call,” Advisor Zhang speculated.

“That’s certainly possible.”

“Sir, do you have a method to counter it?” Advisor Zhang’s concern clearly focused on this point.

“Of course.”

Everyone turned their eyes to Song You, who remained calm and composed, exuding confidence.

“What you may not know is that Phantom Trace, while seemingly impressive and allowing travel with a mere thought, actually comes with significant limitations. If these limitations are unknown, they are of little concern. But once someone understands them, it becomes easy to target and disrupt the technique.”

“Please enlighten us!”

Upon hearing this, Advisor Zhang immediately cupped his hands in salute.

“Advisor, have you ever read ancient texts or stories about divine immortals vanishing into thin air?” Song You asked.

“Is that also Phantom Trace?”

“Whether divine immortals practice Phantom Trace, I cannot say,” Song You replied, “but the ability described in those stories is indeed based on Phantom Trace. It seems the tone was set in ancient times—later generations saw how the old stories depicted it and followed the same pattern.”

“Naturally, I've read such accounts.”

“Then, have you all noticed that in those stories, when immortals vanish after interacting with mortals, it usually happens when the mortals are momentarily distracted—perhaps their gaze shifts, their attention wanders, or the immortal walks behind a tree that can obscure their figure, or a sudden puff of smoke arises, and only then do they disappear?”

“...”

Everyone’s eyes widened as they seemed to recall something and began to ponder.

“Now that you mention it, that does seem to be the case!” someone exclaimed.

“Have you ever considered why this is so?” Song You continued. “Do you think it’s merely to add an air of mystery?”

“Is there more to it?”

“Phantom Trace relies on freedom to achieve its seamless effect. From the moment one begins practicing it, one must remain in isolation, secluded in a cave, cut off from the world. Isolation is freedom, and freedom is key to the technique. Being observed by others disrupts that freedom,” Song You explained slowly. “If someone is watching, the technique loses its fluidity—it’s no longer truly free.”

“...”

The crowd fell silent, deep in thought.

Everyone’s eyes widened once again. Such an advanced technique, and yet it had such a glaring weakness?

They exchanged glances, finding it hard to believe, but Song You’s calm and matter-of-fact explanation left them with no choice but to accept it.

For a moment, it all seemed impossibly profound.

“The records in my temple’s library state that this technique must be cultivated to its absolute peak to allow one to vanish under the scrutiny of countless eyes. However, the texts also note that even if one could achieve the level of traveling the ends of the earth in a single thought, it would still fall short of that ultimate freedom.

“Thus, in ancient times, practitioners of this art had to be extremely cautious. They usually operated at night and often practiced supplementary techniques to aid in concealment and misdirection, to avoid having their method disrupted,” Song You explained.

He added, “Whether these supplementary methods are effective depends on the skill levels of both sides—one attacking, the other countering. As for how this works in modern times, or how effective this particular demon’s methods are, I cannot say.”

“But in Yuanzhi City, the highest point is the city walls. Even so, the city is complex. Looking down from the walls, there are still many blind spots. What’s more, as you said, those who practice this technique often cultivate concealment or misdirection methods.

“Demons, in particular, excel in creating obscuring mists. Even if we station people along the walls or have guards posted everywhere, it would be very difficult to pierce through their illusions and break the technique.”

“Phantom Trace may enable movement with a single thought, and I cannot stop it directly. However, I can offer a method to assist you all in countering it,” Song You replied.

“And how would you defeat this enemy, sir?”

“Bring me ink, brushes, paper, inkstone, and cinnabar,” Song You said, waving his sleeve.