The passage was approximately one meter wide, resembling a long, spiraling jade ribbon clinging to the inner walls of the pit, descending layer by layer into the depths. Flames constantly erupted from the edges of the passage, making the walk feel like traversing a field of fire, especially with the yielding softness underfoot that suggested an immediate plunge into the abyss—a truly heart-stopping sensation.

Fortunately, Nie Kong, Bai Yuqing, and Mu Hongling were not timid souls; despite the perilous appearance of this descent, it could not deter them.

“Apprentice, how did you know there was a path here?” Mu Hongling asked curiously. She finally understood why she had sensed certain Fire Spirit Energy elements being restrained; they had all been sealed by the stone tablet to condense this lengthy pathway within the pit. Before the Spirit Runes were activated, touching it rashly would easily invite a backlash, as these sealed Spirit Energy elements differed vastly from ordinary ones.

“I guessed!” Nie Kong replied with a cheerful smile.

No one believed that answer. As soon as the words left his mouth, Nie Kong received a sharp glare from Mu Hongling. “Hmph, if you won’t say it, then don’t bother! As if your master cares!”

Saying that, Mu Hongling began to muse aloud, “I wonder what kind of place the bottom of this cave is? Before us, no one should have come down here. Perhaps the bottom of Flame Mountain is the very place where the Spirit Master who first carved out the ‘Netherfire Abyss Spring’ cultivated. If so, there might be quite a few treasures inside.”

Seeing Mu Hongling’s look of longing, Nie Kong did not reply. In truth, although he had learned of this route to the bottom from the remnant soul of the ‘Ghostly Eagle King,’ he remained ignorant of what exactly lay hidden below, as the ‘Ghostly Eagle King’s’ memories held little information about Flame Mountain.

The trio descended, and the scene within the pit became progressively clearer. Watching the massive plumes of flame roar upwards, even Nie Kong and his companions felt a shiver of apprehension. If one of those fireballs merely brushed against the passage, they might all end up taking an unintended flight!

After walking for several tens of minutes, the vague outline of the pit's bottom finally appeared.

“We’re almost there!” Mu Hongling’s delicate face flushed with excitement, much like a greedy miser spotting a hoard of glittering gold coins. She waved her little fists and cheerfully rushed downward. “Babies, your granny is coming!” Her crisp voice vibrated through the pit, eliciting immense echoes.

Bai Yuqing’s lips curved slightly, and she subconsciously quickened her pace too.

Nie Kong let out a dry laugh, about to tease her, when his ‘Pet Backpack’ suddenly vibrated...

No, it wasn't the ‘Pet Backpack’ itself trembling, but the half-piece of the ‘Seven-Colored Spirit Leaf’ inside it! Nie Kong hastily shifted his attention. The half-leaf had erupted in a dazzling, emerald-green luminescence.

“This is…” Nie Kong felt confused.

Back in the Yin Ruins, after Mu Jinzhu gave him this half-piece of ‘Seven-Colored Spirit Leaf,’ he had studied it several times. Perhaps because it was only half a leaf, whether he used his Spirit Power or his intent to probe it, the ‘Seven-Colored Spirit Leaf’ revealed nothing. Yet, here, deep within the pit of the ‘Netherfire Abyss Spring,’ it was showing such a significant reaction without any warning.

Could there be another ‘Seven-Colored Spirit Leaf’ here?

This thought flashed through his mind, instantly rejuvenating Nie Kong.

Although he wouldn't be able to use something like the ‘Seven-Colored Spirit Leaf’ for a long time to come, the degree of importance that Mu Qingyi and Nie Shenggong placed on it indicated its immense value. If he could find another one and show it to his mother and Third Aunt, perhaps they might gain some new understanding.

“Apprentice…” Mu Hongling’s sweet cry drifted up from below, pulling Nie Kong’s consciousness back to reality. He responded with a slight eagerness and quickened his steps to catch up with them.

A few minutes later, the scenery at the bottom of the pit was fully visible.

The area spanning hundreds of meters at the base was still sanguine-red, yet remarkably uniform. At the very center of the floor stood a massive dais, shaped uncannily like a giant, inverted bowl—the ‘bowl’s base’ supported by a thick central column, with flames continuously spewing from the ‘bowl’s mouth.’

“Apprentice, Sister Bai, we’re nearly at the bottom. We need to be careful,” Mu Hongling suddenly slowed her pace, turning back to caution them. “Who knows what kind of Spirit Beast might be hiding down here!”

“…”

Bai Yuqing nodded silently, but Nie Kong was slightly surprised. This was exactly what he had intended to remind Mu Hongling about; contrary to his initial impression, she hadn't let her guard down despite her hurried demeanor.

After descending a few more minutes, the yielding, fiery passage transformed into solid ground. Nie Kong, Bai Yuqing, and Mu Hongling finally reached the pit floor.

In this vast space, apart from the whoosh of the erupting flames, there was absolutely no other sound. The ground was smooth as a mirror, capable of reflecting their figures. Apart from the central pillar, there was nothing else to draw the eye.

Exchanging glances, the three channeled their inner Spirit Power and moved silently toward the center of the pit floor.

The pillar soared to over a hundred meters high, like a sky-supporting column. Its circumference was so immense that it would require dozens, perhaps a hundred, grown men joining hands to encircle it. Standing beneath it, Nie Kong, Bai Yuqing, and Mu Hongling instinctively felt a sense of utter smallness.

The surface of the column was engraved with exquisitely intricate patterns—all depictions of various flame motifs. Faintly, streaks of Mu Hongling light flickered between the lines, as if a mesmerizing power radiated from them, forcing Nie Kong and the others to hold their breath in concentration.

“Stairs…” Not long after, a surprised whisper echoed in the area. The three, who had been circling the column, stopped abruptly and stared in astonishment at the staircase winding upwards before them. At this spot, a gap nearly two meters wide and almost fifty meters high had been hollowed out of the column, with steps slanting up into the depth of the fissure.

“Let’s go!”

After a brief look at each other, Mu Hongling waved her jade hand and led the way up the steps, Nie Kong and Bai Yuqing following immediately. Since there were no Spirit Beasts or medicinal herbs at the bottom of the pit, only this single pillar, wouldn't it be a waste to ignore the stairs created by the original owner of the ‘Netherfire Abyss Spring’? Moreover, the half-piece of ‘Seven-Colored Spirit Leaf’ in Nie Kong’s ‘Pet Backpack’ was still vibrating, so leaving now was impossible.

Ascending the tiers of the staircase, they gradually penetrated deep inside the column. When they finally rushed up the last few steep steps and reached the flat passage at the top, the trio froze. The passage was only ten meters long; beyond that was a smooth, Mu Hongling stone wall.

“That’s it?” Mu Hongling grumbled disappointedly.

Nie Kong also frowned. Logically, this situation shouldn't occur; otherwise, why bother carving out the stairs and passage within the column? Driven by instinct, Nie Kong walked to the very end and carefully scanned the stone wall.

“Huh?”

A moment later, Nie Kong let out a soft sound, his expression turning somewhat strange. Hearing him, Mu Hongling and Bai Yuqing instinctively moved behind him, following his gaze. Right in the center of the blood-red stone wall, there was a shallow indentation—almost impossible to notice without getting close.

“A sword?” Bai Yuqing furrowed her brow, and Mu Hongling looked equally puzzled.

Nie Kong nodded. The shape of the indentation was exactly that of a small sword, about half a foot long and two fingers wide, identical to the Ink Sword Key he carried within his robes. If it were just the shape, Nie Kong wouldn't be certain, but the hilt, blade, and tip of the groove each possessed a small, rounded recess, which perfectly matched the slight protrusions on the small ink sword in his possession.

This made Nie Kong even more perplexed. According to Dream Heaven Monarch, the small ink sword was the key to opening the back door of the ‘Dark Soul Hall.’ That implied the back door of the ‘Dark Soul Hall’ should also have a sword-shaped indentation like this one. Could this small ink sword open this place as well?

Or perhaps, this key provided passage throughout the entire ‘Netherfire Abyss Spring’?

By this point, Bai Yuqing and Mu Hongling must have grasped the connection. Bai Yuqing turned slightly, as if preparing to leave, but Mu Hongling shook her head with a hint of resignation. “If we had a key that fit this slot, maybe we could get in. What a shame. Apprentice, let’s go! I thought there would be some good loot here, but we came all this way for nothing. I should have stayed on the mountain to cultivate.”

As she spoke and started to move outward, Mu Hongling noticed Nie Kong hadn't followed, causing her to look back in surprise.

“We haven’t come in vain,” Nie Kong smiled confidently. Then, under the gaze of Mu Hongling and Bai Yuqing, he reached into his robes and pulled out the small, ink-black sword.

“Huh? This sword is…” Mu Hongling was momentarily stunned, then her face broke into an expression of disbelief as she blurted out.

“The key?” Hearing her speak those words, Bai Yuqing’s eyes also brightened. Her cold gaze flickered between the indentation on the Mu Hongling wall and the ink-black sword in Nie Kong’s palm.

“Perhaps,” Seeing Mu Hongling’s eyes wide open, Nie Kong couldn't resist teasing her. “Little Master, you’d better be prepared. If this opens, a Spirit Beast might just rush out and devour your apprentice here. It’ll be hard to find another good apprentice like me then.”

“Go, go!” Mu Hongling fiercely rolled her eyes and impatiently snatched the ink-black sword from Nie Kong’s hand, pressing it firmly into the sword-shaped groove on the Mu Hongling wall. “If a Spirit Beast really appears, your Master will be the first to confront it.”

While it was possible for a Spirit Beast to be found on the outer pit floor, the odds of one being inside this pillar were virtually zero. Even if a Spirit Beast had been sealed within this column long ago, it would surely have perished long since. Nie Kong and Bai Yuqing could easily deduce this. Yet, when they saw the ink-black sword perfectly align with the groove, all three couldn't help but show a flash of anticipation.

. . .