The two sisters walked up to that heavy metal door.
The surface of the door was exceptionally smooth, without any visible keyholes or handles.
The only distinctive feature was a disc-shaped mechanism in the center of the door.
The disc was evenly divided into six sectors, each inlaid with a distinctively colored crystal.
Red, orange, yellow, green, blue, purple.
Below the disc was an inscription in archaic Common, completely different from the crooked graffiti of the goblins:
"The order of colors, follow the rainbow light."
Selene tilted her head and tapped her chin with her finger: "Rainbow light? The order of the rainbow? Red, orange, yellow, green, cyan, blue, purple?"
She furrowed her delicate brows.
"But there is no cyan here."
"Perhaps in the visual spectrum of certain creatures, cyan and green are the same thing."
Celeste was lost in thought; her gaze didn't linger on the crystals but fell on the edge of the disc.
It was covered in fresh scratches and prying marks, reeking of violence and impotent rage.
They were left by the goblins.
"It seems this is the reason why those green-skins couldn't open this door."
Celeste's lips curled slightly, her tone carrying a hint of amusement.
"Expecting creatures whose aesthetics are limited to'shiny is good' and who struggle to count to understand spectral ordering is indeed asking too much of them."
She extended her finger, tracing an elegant arc in the air.
Then, she touched and rotated the red, orange, yellow, green, blue, and purple sectors in sequence.
Her movements were fluid and natural, without a shred of hesitation.
With each turn, the corresponding crystal grew brighter.
When the final purple sector was rotated into place, the light from the six crystals instantly merged, converging in the center of the disc to form a miniature rainbow halo.
"Click—" A crisp sound of a mechanism unlocking.
The heavy metal door slid open inward with the muffled sound of rock grinding against rock.
Behind the door was a stone-paved corridor, impossibly clean.
"It's that simple?" Selene could hardly believe her eyes. "Those goblins couldn't solve such a simple puzzle?"
"For goblins, sorting colors is as difficult as making them do multiplication problems." Celeste put away her pink staff, her tone flat.
"In their worldview, all shiny things are classified as 'good,' and there's simply no need for more detailed categorization."
[Ding! Successfully solved the color puzzle that goblins couldn't crack, creating joy by crushing them with intellect, joy value +20! Host, your common sense is a superpower in front of goblins!]
The two sisters smiled at each other and stepped into the corridor behind the door.
The metal door slowly closed behind them.
The stench and chaos of the goblin nest outside, along with those thirty-three corpses, were completely shut out.
The world behind the door made The two sisters, who had just completed a "perfect infiltration," hold their breath in unison.
This... was another dimension.
Outside the door were rough, primitive caves; inside, however, was an orderly creation of civilization.
Underfoot was no longer uneven rock, but gray stone slabs laid seamlessly.
Each piece was polished as smooth as a mirror, clearly reflecting the soft white light emanating from the walls.
That light did not come from glowing moss, but from some kind of crystal embedded in the walls, arranged in an orderly fashion with constant radiance—clearly a creation of some civilization.
The air was dry and clean, carrying a faint scent of dust mixed with metal, worlds apart from the damp, foul-smelling environment outside.
The corridor was wide and straight, with walls made of neatly cut stone and a towering vaulted ceiling overhead.
Simple, sturdy, and practical.
Everything exuded a profound aesthetic polished by time.
It formed an absurd and stark contrast with the chaotic, random, "use whatever you find" architectural aesthetic of the goblins.
"This..." Selene opened her mouth, her footsteps subconsciously lightening, fearing that the mud on her boots might defile this pure land.
"What is this? This floor is cleaner than our living room! Did we accidentally stumble into some ancient ruin?"
Celeste crouched down, her fingertips brushing against the cold stone floor, feeling its absolute flatness.
She nodded.
"It's possible. Look at the precision of the stone cutting, the craftsmanship of the embedded lighting crystals..."
She stood up, her gaze sweeping over the deep and tidy corridor ahead.
"The goblins outside must have stumbled upon this place by accident and turned the outermost natural cavern into their dormitory."
[Ding! Abnormal civilization creation discovered, "Castle Mystery" quest has been updated to exploration quest "Relic Tracking"!]
[Quest Requirements: Explore this place and find the truth about the ruins.]
[Quest Reward: Distribute joy value and random Rewards based on exploration completion.]
[Host, it seems the goblins are just the guard dogs here (and not very smart ones at that)?]
The two sisters concealed their presence and carefully moved along the corridor, vigilant against any possible incidents.
Occasionally, closed stone doors appeared on both sides of the corridor, carved with simple geometric patterns. They tried to push them, but the doors remained unmoved, as if they were fused with the mountain itself.
After walking for about five minutes.
A rhythmic tapping sound faintly came from ahead in the corridor.
Ding... Clang... Ding... Clang...
It sounded like metal colliding with rock.
In between, there was also some low, muffled conversation.
The two sisters exchanged a glance, their figures merging into the shadows by the wall, their footsteps as light as felines.
At the end of the corridor was a much wider space, resembling a large workshop.
The scene before them made them hold their breath once again.
In one corner of the hall, several stout creatures were busy working.
Their bodies seemed to be molded from rock and soil; they were stocky, with arms thicker than the thighs of The two sisters.
At this moment, they were wielding delicate iron hammers and chisels that seemed ill-suited to their size, clanging away at a giant boulder, seemingly carving something.
Their skin was dark brown or grayish-black, like weather-beaten mountain rock. Their movements were slow and steady, carrying a rock-like composure.
Information came from the bracelet:
[Earth Spirit Craftsman Lv.18]
[Points: 30/each]
[Traits: An ancient race born from the earth, gentle in temperament, skilled in forging and stonework, with astonishing strength, but slow movement.]
[Remarks: Silent craftsmen, solid partners. Don't be fooled by their slow movements; they can smash you into the ground if they swing their hammers. Of course, when facing such a gentle race, combat is not the only option.]
On the other side of the hall, near some makeshift shacks against the wall, another group of creatures had gathered.
They were about the same height as goblins, their skin a sickly pale color from long deprivation of sunlight, and their eyes were huge, glimmering in the dim light.
They appeared extremely uneasy, huddled together, whispering in fragmented, stone-grinding sounds, nervously watching the direction where the Earth Spirits were working, and occasionally glancing fearfully in the direction where Celeste and her sister had come from.
[Cave Dweller Lv.12]
[Points: 10/each]
[Traits: A fragile race that has lived underground for a long time; timid, sensitive, possessing certain night vision abilities and a talent for mineral perception.]
[Remarks: Poor creatures of the underground world, usually attaching themselves to stronger races for protection.]
Earth Spirits and Cave Dwellers? How could they be here?
And it looks like the Earth Spirits are working, while the Cave Dwellers seem like... refugees who are imprisoned or forced to stay here?
Just then, a Cave Dweller near the stone pillar where The two sisters were hiding seemed to notice something.
It jerked its head around, its large eyes locking onto the shadows in terror, and let out a short, sharp squeak!
This scream shattered the peace inside the workshop.
All the tapping and whispering stopped instantly.
The Earth Spirits stopped their work and slowly turned around. Their stone faces showed no expression, but their eyes, embedded in rock, all looked over, and they gripped their iron hammers and chisels tighter.
The Cave Dwellers caused an even greater commotion, like a frightened swarm of rats, desperately shrinking into the depths of their shacks, looking fearfully at the strangers who had suddenly appeared.
An Earth Spirit that looked the oldest and had the longest beard took a step forward.
It put down its weapon and looked at the area behind the stone pillar with steady eyes. A low, slow voice with a texture like grinding rock sounded:
"Come out, strange intruders."
"The green-skinned noisemakers outside... did you deal with them?"
Although its Common was slow, it was exceptionally clear and standard.
They couldn't hide anymore.
Celeste and Selene exchanged a glance and walked out from behind the stone pillar.
When they saw that only two young human females had walked out, the Earth Spirits seemed to heave a sigh of relief, their tense bodies relaxing slightly, but the vigilance in their eyes did not diminish.
The Cave Dwellers were even more terrified.
Celeste remained guarded but showed no hostility. She nodded and replied to the elder Earth Spirit: "Yes, the goblins outside will not disturb this place for the time being."
The elder Earth Spirit scrutinized them carefully, its gaze lingering for a moment, especially on the pink staff in Celeste's hand that felt so out of place with the surrounding environment.
"Thank you for driving away the noise and chaos."
"They have occupied the entrance for a long time, noisy and greedy, disturbing the tranquility of the'Stone Hall' and cutting off our connection with the outside world."
It paused and continued in that slow tone: "I am Shi Xu, the guardian here. These,"
It pointed to the Cave Dwellers behind it, "are the 'Wall Nest Clan' temporarily residing here. And you, are humans? Why have you come to this forgotten 'Cornerstone Hall'?"
Thoughts raced through Celeste's mind.
These Earth Spirits showed no hostility and detested goblins.
She weighed her words and said half-truthfully: "We came here to find 'moonlight moss.' The goblins outside were blocking the way, so we had to... clear them out."
"moonlight moss?" Shi Xu Earth Spirit's rock-like eyebrows (if you could call them that) twitched, "There is indeed some of that glowing moss in the deeper 'Crystal Cluster Cave.' But there..."
Before it could finish, an individual among the Cave Dwellers, who seemed to be the leader, rushed forward a few steps, trembling.
Its pale fingers were nervously twisted together, and it shouted at Shi Xu in a high-pitched, trembling voice: "Sh-Shi Xu Elder! Sh-she... they have the stench of those green-skinned bandits outside on them!!"
"And... there's also a very strange, very scary floral scent! Are they... are they with those bandits?!"
Celeste, Selene: "..."
The stench of goblins was understandable, after all, they had just experienced a slaughter.
But that "very strange, very scary floral scent"...
Celeste was expressionless, with only one thought in her mind—that damn floral scented spray must be listed as a forbidden alchemical item, never to see the light of day again.
Shi Xu Earth Spirit turned to the Cave Dweller leader, its voice still steady: "Biezhao, calm down. They dealt with the green-skins; that is a fact. As for the scent..."
It looked at Celeste again, and a trace of imperceptible helplessness seemed to appear on its rock face.
"Perhaps it is the traces left by some... unique combat method?"
Celeste remained expressionless, but inside, she just wanted to drag out the manufacturer of that spray and beat them up.
[Ding! Because of the lingering "suspicious scent," your identity was questioned by the underground race, creating unexpected awkwardness and humor, joy value +77! Host, the aftereffects of your "chemical weapon" are beginning to show!]
Celeste forcibly ignored the system's snark and said to Shi Xu: "We are not with the goblins; we are just passing through. If the moonlight moss is deeper inside, we are willing to trade items of equal value or help solve some trouble as a Reward."
She spread her hands to show goodwill.
Shi Xu Earth Spirit was silent for a moment, seemingly weighing the options.
It looked at the terrified Cave Dwellers behind it, then at Celeste and Selene, and finally, its slow voice sounded again:
"Perhaps... your arrival is not a coincidence."
"The Cornerstone Hall has indeed encountered some... troubles that we ourselves cannot solve."
Its rock-like gaze became deep.
"If you are willing to listen and prove your strength and goodwill, the moonlight moss, and perhaps even more, can be discussed."
"After all, intruders who can ascend the goblin blockade and leave Biezhao so 'deeply impressed'..."
"You are the first."