Few situations could sour Gu Yi’s mood, and this one clearly qualified. No matter how refined his spellcasting, Gu Yi was a man, not an immortal. Within the confined space of the “Accumulated Grudge Death Realm,” their combined power felt inadequate; beyond merely managing the onslaught, dismantling this death realm seemed far from easy.

Bai Ru reached out and pulled Gu Yi back into the section of the sewer where they had first appeared, retreating to about the middle. She swiftly pulled a peach-wood talisman from her person, tossing it to Gu Yi. “Set up the Eight Trigrams Protection Array here. Let’s see if it can hold off these vengeful spirits.”

Gu Yi pondered for a moment. This seemed like the only viable option. If they remained surrounded by the vengeful spirits, they might eliminate some in the short term, but the entities outside were clearly the residual resentment of all beings gathered in the death realm over the past two decades, amplified by the inherent power of the “Accumulated Grudge Death Realm.” If they chose a direct confrontation, they would be drained of their magical energy in fifteen minutes at most, leading to the same fate as becoming two empty husks with their souls sucked away.

The reason Bai Ru chose the section of the sewer nearest the entrance was not just because it felt relatively safe when they passed through, but also because it lay outside the primary control zone of the “Accumulated Grudge Death Realm.”

The pair swiftly arranged the formation. Bai Ru unceremoniously plunged the head of her Demon-Subduing Cudgel straight down into the center of the array to bolster its magical strength. Instantly, a semi-circular shield, flowing with golden light, expanded outwards from their center, enveloping a perimeter of over ten meters around them.

Thanks to the infusion of power from the Demon-Subduing Cudgel and Gu Yi’s own augmented magic, this protective barrier was vastly more potent than the one Bai Ru had deployed on the Yin-Yang Road; it could even transition from defense to offense when necessary.

As the Eight Trigrams Protection Array activated, a blackish-green mist surged toward the sewer entrance where they sheltered. The fog emitted chilling, mournful wails, punctuated by the intermittent flashing of dark red shadows.

This boundless expanse of mist choked the iron grating at the entrance, refusing to dissipate, churning and rolling with a terrifying, savage appearance.

Occasionally, tendrils of black vapor separated from the main mass, slipping through the iron bars and flying rapidly toward them. However, these wisps were instantly intercepted by the shield generated by the Eight Trigrams Protection Array, dissolving into the air.

It appeared that in this section of the sewer, lacking the direct empowerment of the “Accumulated Grudge Death Realm,” the vengeful mist—formed from countless spirits—could not penetrate the area as a whole.

Although Bai Ru sighed with slight relief, she remained puzzled. “Shouldn't this kind of vengeful mist pursue the yang energy radiated by a living body to devour the living? Why is it just staying put? Could it not sense our yang energy?”

Gu Yi observed carefully and shook his head. “There’s a force controlling this mist. That’s why it’s blocking the entrance and exit instead of surging in to consume us.”

Bai Ru frowned; this was different from what she had anticipated. She had hoped that the mist, stripped of the Death Realm’s bolstering effect, would flood into the sewer, allowing them to fight the spirits comprising the fog using their enhanced Protection Array. In her mind, without the Death Realm’s support, even this massive mist shouldn’t withstand the array supercharged with magical power.

Gu Yi, conversely, completely relaxed. He dismissed the concern with a wave of his hand. “It doesn’t matter. This place is relatively safer, and with your Demon-Subduing Cudgel supporting the array’s power drain, we can match it blow for blow indefinitely. I trust that the ability constraining the vengeful mist won't last long. Shall we race to see who runs out of power first?”

Bai Ru could only nod. With no other effective countermeasure available for the current situation, the two sat down inside the barrier. First, it allowed them to recover from the prolonged physical exertion; second, it gave them a chance to analyze their predicament.

Gu Yi slid to sit against the wall, stretched languidly, and let out a breath.

Bai Ru surveyed their surroundings with lingering unease, occasionally glancing toward the distant cloud of vengeful mist.

Gu Yi glanced at her and asked, “What are you looking for?”

“I’m worried about that small, dark human shadow. You forgot, it can appear and disappear through walls and floors. I’m afraid it’s planning some new trick,” Bai Ru replied.

Gu Yi waved his hand dismissively. “Relax. Nothing is happening right now. Trust that whatever it is, our all-encompassing, invincible iron-clad shield can block it.”

Bai Ru managed only a strained smile at his exaggerated description.

Gu Yi urged her, “Come on, rest a bit. If your nerves are too taut, they’ll snap.”

Saying this, he patted the ground beside him. “We’re filthy anyway, so let’s sit down and take a break.”

Bai Ru walked over but didn't sit. Instead, she leaned against the wall. Just as Gu Yi said, they were entirely soiled, but influenced by deep-seated instinct, Bai Ru still couldn’t sit casually on the ground as Gu Yi did.

In the rare moment of quiet, Bai Ru suddenly asked Gu Yi, “What do you think all of this is for?”

Gu Yi paused, then asked, “You mean… what? Are you asking about what we’re doing?”

Bai Ru smiled faintly. “No, I mean, what is the purpose behind everything happening in this sewer?”

Gu Yi then understood. He thought for a moment. “Do you have a theory?”

Bai Ru marshaled her thoughts. “You said this barrier was man-made. I suspect it’s definitely connected to the people Wu Zhong saw. They placed a moving corpse and a child here—Principal Hao’s grandson. And the small figure that appeared before us was also a child. If I had to guess, that was most likely Principal Hao’s grandson, and he has already been possessed by other souls. Oh, and what’s the function of this barrier you mentioned?”

Gu Yi stroked his chin. “There are many esoteric uses for barriers in Black Sorcery, but the primary focus isn't the barrier itself, but what is controlled within it. Depending on what is placed at the center of the barrier, the effect changes. It can bring sudden wealth and fame, or it can be used for murder, coercion, or blackmail. To put it simply, a skilled dark sorcerer can achieve different outcomes using just one barrier.”

Bai Ru took a breath. “A soul possessing a child’s body, needing to kill a pure-yin adolescent within a certain timeframe, and now there’s an additional boy they absolutely must obtain. What does that suggest to you?”

Gu Yi nodded thoughtfully. “This soul needs to switch bodies. His target is Li Jin.”

Although they still didn't know the ultimate goal of the person who set up this barrier, one thing was becoming clear: why Li Jin was the target. It was simple; if the intent was purely to kill him, he would have died ten times over before all these subsequent events transpired.

Gu Yi spread his hands. “So, finding the person behind the barrier arrangement is our final objective.”

Bai Ru affirmed with a forceful “Mm-hmm.” “Yes. For Principal Hao, for those dead students, we must investigate this to the very end.”

“Wow, I rarely see you so serious,” Gu Yi commented.

“Black Sorcery is truly malevolent, achieving its aims by sacrificing the lives of innocents. Is that something a human should do?” Bai Ru grew slightly agitated.

Gu Yi quickly raised his hand and made a calming gesture in the air. “Easy. When we get out, I’ll find a few people who understand Black Sorcery, and we’ll track down this mastermind, okay?”

Bai Ru calmed her emotions and suddenly added, “One more thing—we need to find Li Jin as soon as possible.”

Gu Yi grinned smugly. “I trust he’s still very safe right now.”

Bai Ru pondered for a moment and understood what he meant. If the goal was Li Jin’s body, the soul hadn’t appeared yet, meaning the soul possessing the child’s body hadn’t been able to make a move on Li Jin.

“Is the restriction you placed on Li Jin foolproof?” Bai Ru asked with residual worry.

Gu Yi laughed. “Not on his body, but inside it. I guarantee that if that soul dares to forcibly inhabit Li Jin’s body, its fate will be utter annihilation. But sadly, I suspect it’s likely aware of that.”

Bai Ru sighed. “I don’t know how long this stalemate will last. I really want to resolve these matters quickly; there’s still a mountain of issues piling up on the Non-Ordinary side.”

Gu Yi shrugged. “Don’t worry. It’s past midnight now, right? We should be close to a resolution before dawn. I believe controlling that cloud of vengeful mist is much more troublesome for them than it is for us. As soon as the guy behind this loses control of the mist, that’s our cue to solve the problem. It will still take some effort then, so you should focus on resting now.”

Bai Ru let out a soft, noncommittal “Hmph.” Within the Eight Trigrams Protection Array, she could indeed afford a brief reprieve. The two took turns keeping a watchful eye on their surroundings, slowly restoring their strength. Bai Ru tried to ensure Gu Yi rested more, as the magical energy he cultivated was the key force against the entire ordeal.

However, the entity hidden within the barrier certainly wouldn't allow them such ease. Time slowly passed, and the vengeful mist outside seemed to be growing larger, its churning becoming increasingly violent.

But this wasn't the tool aimed at them. As the pair watched the mist surge like a raging sea, an unusual sound reached their ears, gradually approaching them from the other side.

Instinctively, they both turned their heads toward the other direction…