Everyone hastily aimed their flashlights toward an area just to the right of the stone door. Scholar Jia rubbed several protrusions that were almost the exact color of the stone wall, muttering excitedly to himself, "Good heavens, this is the Seven-Star Interlocking Lock."

The group looked at Scholar Jia, filled with confusion, as he turned back to them, pointing at the barely visible protuberances on the stone wall. He said to the crowd, "Do you see these small dots that stick out? Their arrangement follows the Big Dipper in the heavens. These seven protrusions are the mechanism to open this stone door."

Young Master Liu couldn't help but ask, "Then why is it called the Seven-Star Interlocking Lock?"

Scholar Jia blinked his small eyes and explained, "Everyone has heard of Guiguzi, the teacher of Sun Tzu during the Warring States period, haven't you? Guiguzi, whose given name was Xu, was from the State of Wei (modern-day Qixian County, Hebi City, Henan). He excelled in self-cultivation, the art of diplomacy, was proficient in military strategy, martial arts, and esoteric bagua. He authored the fourteen-chapter military treatise Guiguzi. He is known in folklore as the Ancestor Wang Chan, a towering figure in Chinese history during the Spring and Autumn and Warring States periods, one of the 'Hundred Schools of Thought,' the progenitor of the School of Diplomacy, and also a highly accomplished educator. He often ventured into Yunmeng Mountain to gather herbs and cultivate the Dao. Because he lived in seclusion in the Ghost Valley of Qingxi, he was called Master Guiguzi. This Seven-Star Interlocking Lock mechanism was first created by him. This mechanism is exquisitely ingenious; each star's protrusion is connected to a pivot point. These seven stars represent seven pivot points. Inside the stone door is a master pivot, which must be precisely activated one by one by the seven star pivots according to the rotational direction of the Big Dipper to trigger the master pivot within the door, allowing the stone door to open."

The others gasped in amazement, marveling at the intelligence and ingenuity of people from the Warring States period, capable of creating such a refined mechanical lock.

Scholar Jia continued, "Of course, if we miscalculate and fail to press the seven stars in the predetermined order and timing, this stone door will never open. Furthermore, there might be unknown dangers lurking."

Seeing that everyone seemed about to ask more, Scholar Jia smiled knowingly and went on, "The Seven-Star Interlocking Lock is rumored to have been first used in the secret treasury of the Chu State's imperial city during the Warring States period, as Guiguzi once served as the Prime Minister of Chu. Ancient texts record that a spy from the Qin State infiltrated the Chu imperial city, attempting to steal from the secret vault. Because he triggered the Seven-Star Interlocking Lock, he was killed. The reason is that if the seven stars are pressed correctly, they engage the master pivot; but if pressed incorrectly, those seven stars might be connected to the master pivot that drives a lethal mechanism."

"Are you saying there might be hidden killing mechanisms inside this stone door?" Fan Debiao asked, bewildered.

Scholar Jia nodded and said, "Perhaps inside the stone door, or perhaps surrounding it. Ancient people, when burying treasures, building tombs, or concealing anything important, always set up killing mechanisms, such as in ancient tombs. Especially in the burial sites of major historical figures, there are often countless mechanisms and hidden weapons, poison, and volatile substances. This is all to protect their remains from desecration by enemies or future generations. Common examples include: when a mechanism is triggered, there might be pitfalls, poisonous fires, projectile weapons, gunpowder, shifting sands, and so on. Let's focus on this stone door: if the seven stars activate a killing mechanism, maybe a trap will open beneath our feet, heavy sand might fall from overhead, or poisonous fire and hidden weapons might erupt from the four walls."

Everyone was struck dumb; the ingenuity of the ancients was truly remarkable. Of course, so were their cruel methods. If the ancients had been as 'civilized' as modern people—opting for cremation—there would be no need for these traps and mechanisms; it would have been so much simpler.

Scholar Jia added, "Actually, these mechanical traps and hidden weapons are relatively easy to guard against. The ancients possessed many more anti-theft techniques that you are unaware of. For instance, raising peculiar, evil creatures to guard tombs—such as 'corpse raising' or breeding ancient beasts. Some who understood sorcery or witchcraft might even keep strange entities. We won't go into detail here."

Having said that, Scholar Jia pulled out a peculiar, dark, octagonal object from his robe. He smiled and said to the group, "This is an astrolabe that people used in ancient times to calculate celestial phenomena. It is engraved with precise astronomical alignments. By turning the astrolabe, the celestial phenomena depicted upon it will change, allowing us to accurately determine the orientation of the seven stars."

He casually asked, "Does anyone have a watch? What time is it?"

Young Master Liu looked at the watch on his wrist and replied, "A quarter to one in the morning."

Scholar Jia nodded, then adjusted the pointers on the astrolabe and instructed everyone, "Focus your flashlights on my hand and the seven star protrusions."

He then carried the astrolabe to the stone wall where the seven stars were located. The others quickly concentrated all their flashlight beams on the area he indicated, watching his movements tensely.

Scholar Jia also seemed a bit nervous. He took a deep breath, then stared at the shifting celestial alignment on the astrolabe, slowly extending his hand to trace the seven star protrusions.

Everyone held their breath, watching as his finger suddenly pressed one of the star positions. A crisp "click-clack" sound echoed from inside the stone door. Young Master Liu felt sweat bead on his forehead, his heart pounding violently.

Scholar Jia continued pressing the other star positions on the wall. In just over ten seconds, accompanied by a continuous series of "click-clack" sounds, the stone door began to tremble slightly. When his hand stopped, the door suddenly seemed to freeze, emitting no further sound or vibration. Just as everyone's spirits sank, fearing the old man had pressed the sequence incorrectly, the stone door suddenly let out a deep, muffled boom, sending a shiver of dread through everyone. As they stood there, hearts pounding, the stone door slowly began to rise. A smell of decay seeped out from the gap beneath the door, creeping into the nostrils of the group.

As the stone door slowly ascended, everyone's hearts were suspended in anticipation. What kind of scene lay beyond? What strange things would they encounter? After a dull clank, the door stopped rising. Inside the stone doorway, there was profound silence, and an oppressive, gloomy atmosphere rushed toward them.

Scholar Jia raised his tinderbox and slowly approached the entrance, peering in. After a few seconds, he seemed unable to see clearly through the small flame. He turned back and said, "Focus the flashlights over here and illuminate the interior."

As seven or eight flashlights shone into the opening simultaneously, the scene inside astonished the group. It was a vast, subterranean canyon. The black cliff face on the opposite side stretched endlessly to either side, and their current location was on the cliff face directly opposite that opposing precipice.

Scholar Jia extinguished his tinderbox, took a flashlight, and shone the beam downward. A winding stone staircase descended into the darkness, its depth unknown.

Scholar Jia turned back and said, "It seems the construction here is magnificent. Although I cannot yet see the underground structure, this natural subterranean canyon tells me a great deal. Everyone, follow closely behind me, slowly and carefully."

The steps were narrow and steep, apparently carved by artisans following the natural slope of the cliff face, chipping away bit by bit. One by one, they followed Scholar Jia, descending slowly.

After about ten minutes, they finally reached the canyon floor. The scene before them was breathtaking.

A massive underground canyon opened up to their view, perhaps a hundred meters wide, with a length that seemed endless in either direction. Both sides were flanked by towering, steep cliffs, as if sliced by an axe.

Scholar Jia gestured for everyone to wait, then cautiously moved forward, shining his flashlight on the ground ahead. After advancing about ten meters, he beckoned for the others to join him.

When the others caught up, Scholar Jia was crouching on the ground, examining something. As they neared, a strange odor filled their breaths. Looking ahead of Scholar Jia, they saw a pitch-black subterranean river flowing sluggishly in the direction of the canyon.

Scholar Jia sniffed deeply and said, "Strange, this dark river appears to be entirely oil. Everyone, be careful; no smoking. One stray flame and we could all be finished."

Young Master Liu asked, "So, which way do we go now? Upstream or downstream?"

Scholar Jia replied, "Based on the orientation, we should head downstream."

Scholar Jia stood up and continued, "Everyone must remain highly vigilant. I feel extremely uneasy here; this is a gut feeling born from multiple near-death experiences underground. The moment that stone door opened, I sensed an inexplicable, malevolent aura filling this space. Therefore, everyone must watch out for each other and remind one another. If you detect the slightest abnormality, you must alert the group immediately."

The others all nodded. Scholar Jia waved his hand and said, "Let's go!"

Thus, the group followed the oil river in the underground canyon, proceeding downstream.

Along the way, besides the sound of their footsteps and breathing, everything was frighteningly silent; even the slowly flowing oil river seemed utterly lifeless. This silence made everyone feel overwhelmingly suppressed and terrified.

After walking for about fifteen minutes, a massive shadow suddenly appeared ahead, resembling a crag or perhaps a large structure. However, in the darkness, they could only discern the huge silhouette, unable to make out the full form.

Suddenly, they heard Fan Debiao curse, "You damn green worm, why are you grabbing my backside? Trying to get handsy?!"

"Your mother's! When did I grab your backside?" Green Worm shot back from behind Fan Debiao.

Young Master Liu turned back and snapped, "Can you two stop fooling around! Have you forgotten where we are?"

At that moment, Green Worm also shouted, "You in the back, who the hell just felt my butt?!"

Yang Weidong, standing behind him, quickly protested, "I didn't touch your butt."

Just then, Scholar Jia called out, "Everyone, careful, there's something here!"

He was seen raising his whip and swiftly moving toward the rear of the group. Everyone quickly looked back to see a thin, dark shadow flash up from behind Yang Weidong, leap onto the mountain wall to the right, and vanish without a trace in the blink of an eye.

Fan Debiao, still shaken, swore, "What the hell was that thing? Always grabbing my butt." Young Master Liu stared at the small dark shape for a moment, then said grimly, "If my guess is correct, that was an Yin Monkey."

"What? An Yin Monkey? What's that?" Fan Debiao asked, surprised.

Young Master Liu explained, "The Yin Monkey is a strange beast recorded in ancient texts as dwelling in the Netherworld. Legend says this creature is inherently lustful and cunning, adept at sucking out a person's vital essence and blood. Once it targets you, escape by having your life force drained is impossible."

Scholar Jia walked over, interjecting, "The kid is right. That thing just now was indeed a young Yin Monkey; it was too small, only reaching your rear ends. If it had been an adult Yin Monkey, the comrade whose rear end was touched would have been in deep trouble."

Fan Debiao asked foolishly, "What would have happened then?"

Scholar Jia chuckled, "Then it would have grabbed your nape. What do you think would happen? In a few dozen seconds, you would have turned into a dried-up corpse."

Fan Debiao and Green Worm exchanged glances, cold sweat breaking out. Scholar Jia shook his head and said to Young Master Liu, "Your two brothers are a bit dimwitted. I don't know why they were chosen by Big Cricket to go grave robbing."