"Trapezoid...!!!"
The girl wasn't foolish. Upon hearing this explanation and observing the room's layout again, she suddenly realized the truth.
Their vision had been deceived!
The room was a single cement color, and in this hue, lines of varying lengths were the easiest to misjudge with the naked eye.
Moreover, the most crucial point was that this was Room 2013!
Normally, the adjacent Room 2012 housed the [Fallen Witch], and the nearby rooms were all mentally contaminated.
No one would wander around this area.
Even if someone passed by, their mental faculties would be disturbed, causing them to overlook such details.
Visual deception combined with mental interference led to the iron door distance difference being ignored by people.
The discrepancy in door distance... This was a completely new discovery, never recorded in even the most detailed information from the intelligence merchant.
What a clever design!
The mechanical-arm girl understood everything. She looked at the weak-looking man who seemed fragile enough to be killed with a single blow, utterly astonished: How did this guy detect something so subtle amidst such interference?
This was beyond what mere attentiveness could explain.
"..."
Ji Xun finished speaking, his expression unchanged, not thinking it was a big deal.
In fact, he had noticed this issue a long time ago but didn't want to make trouble.
At that time, he didn't trust this temporary teammate enough and wanted to lay low until the third day to leave, so he didn't mention it.
But now things were different.
.....
Actually, besides what he had said, there were many details Ji Xun hadn't explained.
The structure of this bunker was very simple, a "亖"-shaped building, with one hundred rooms per floor and only one rusted elevator connecting the floors.
The design itself was problematic.
Firstly, the bunker's purpose was evident from its name, [407 Anomalous Biological Containment Facility], which clearly suggested it was some sort of research bunker.
But did a laboratory only have places to imprison monsters?
The normal structure of a research facility would likely be easily analyzed for the locations of other rooms, so they created this misleading parallel structure.
Following this train of thought, systematically checking the room layout would reveal problems.
Of course, this was provided that one wasn't disturbed by the abnormal mental field on the second floor.
Ji Xun had an unusually keen sense of observation for his surroundings and noticed the problem after taking a few steps.
He then deduced the entire spatial design issue.
Since it was determined to be a "clearance, reward" dungeon, discovering a hidden door was not the most interesting part for Ji Xun.
What intrigued him more was deducing the motives behind the design of this checkpoint.
...
The mechanical-arm girl had completely let go of her underestimation of her temporary teammate.
Time was of the essence, so she went directly to the wall Ji Xun had marked.
There was even a detailed "✘" mark on the door frame.
Without delay, she raised her now fully-charged mechanical arm and aimed at the mark, reminding, "Step back."
Ji Xun naturally hid behind the girl.
Then, with a "boom," the blast almost knocked them off their feet.
Both simultaneously heard the sound of bricks shattering inside the wall.
"It really broke open!"
The mechanical-arm girl looked at the large hole she had blasted, filled with disbelief.
Although she had been told the reasoning earlier, finding a new way to clear the level felt surreal.
This meant that the [407 Anomalous Biological Containment Facility] clearance method might be as the man said—they had found a new path to clear the level!
Ji Xun looked at the broken hole, feeling no joy as he had already been certain.
He looked at the dark hole, appearing thoughtful.
Breaking through the wall was easy, but it didn't mean that triggering the hidden plot would be of low difficulty.
On the contrary, he believed the designer was confident in their subsequent design, hence not doing more with the wall.
Before he could think further, as the wall's dust hadn't settled, they both saw a new prompt: "Triggered hidden plot, exploration increased by +5%, gained additional reward upon settlement."
The mechanical-arm girl cautiously examined the hole in front of them, resembling a laboratory area. The eerie green glow gave a constant psychological suggestion of monster ambushes.
Ji Xun seemed indifferent, calling out, "Let's go in and have a look."
"..."
The mechanical-arm girl glanced at him and then stepped in front of Ji Xun, taking the lead.
She was very aware of her role in this cooperation.
Earlier, she had taken the lead; now it was his turn.
...
The room was a very messy laboratory, with battle marks everywhere. There were dried bloodstains and several dried skeletal remains in white lab coats on the floor. There were also claw marks from unidentified creatures on metal instruments.
Scattered beakers and reagent bottles covered the cluttered medicine table, dissection surgery tables, and monster specimens soaked in yellow-green liquid, along with various bizarre tools...
The instruments had a strong steampunk black technology style, exuding a thick magical mysterious aura.
It looked like both an alchemy and a biological laboratory.
The mechanical-arm girl cautiously walked ahead, surveying the room, saying, "This should be the research room of Bunker 407."
Indeed, it was impossible for a research facility to only have places to imprison monsters.
Ji Xun scanned his surroundings and nodded, "Hmm. Let's find some useful clues."
"..."
The mechanical-arm girl glanced at him, unsure why he spoke so confidently, as if certain they'd find something.
The laboratory was eerie and dim, but visibility was decent due to the gas lamps.
The laboratory was large, and faint rustling noises occasionally echoed from the darkness, from unknown creatures.
Ji Xun scanned the layout and walked straight towards a row of rooms on the left.
The mechanical-arm girl followed without a word.
Ji Xun walked through, briefly checking some rooms and just glancing at others before moving on.
"What are you looking for?"
"Not sure yet."
"..."
The mechanical-arm girl felt somewhat baffled. Was this guy not looking for an exit but rather some unknown clues?
Soon, Ji Xun stopped in front of a room, saying solemnly, "This should be it."
The mechanical-arm girl saw that this room was larger than the previous ones, seemingly an office for management.
Before she could understand why they stopped there, Ji Xun had already started rummaging through the room. Soon, he found a safe in the corner.
A safe?
It looked like an important plot item.
Before the mechanical-arm girl could marvel at his certainty about the item's location, she saw Ji Xun pull out some crooked metal pieces, place his ear against the safe, and start fiddling with the lock.
It was a "master key."
Ji Xun had made it during his free time that day.
Originally, it was to deal with the iron locks in the cabins.
Although this world had extraordinary powers and magical cards, the locks were still mechanical. No matter how complex, there was a way to open them.
Fortunately, this safe wasn't too complicated for Ji Xun.
"..."
The mechanical-arm girl quietly watched from the side, not interrupting.
This man's calm demeanor gave a sense of reliability.
She wasn't in a hurry to find an exit anymore.
The laboratory was quiet, with only the sound of gears grinding in her ears.
Suddenly, a crisp metal click echoed.
Ji Xun smiled faintly, whispering, "It's open."
That fast?
The mechanical-arm girl was also surprised.
Watching his professional safe-cracking skills and recalling his earlier analysis of the wall problem, she couldn't help but curiously ask, "What exactly is your profession?"
"Profession?"
Ji Xun pondered briefly and replied, "I'm an actor."
**Girl:** "I mean your profession sequence. Are you a master thief?"
She had thought he had extraordinary mental powers, but that didn't seem to be the case.
"..."
Ji Xun couldn't answer.
Before he crossed over, he was an actor.
Raised by a circus, he had been a clown performer.
That inexplicably high mental strength was related to his profession.
The clown played too many roles. One day, while performing, he realized he didn't know which one was his true self.
Or maybe every role was a part of him.
Ji Xun clearly felt that there were many versions of himself in his mind, playing different roles.
He always appeared calm, not because he had no "fear" but because it was suppressed by "reason," "curiosity," "excitement," "knowledge-seeking," and "twisted madness," among other roles.
This overloaded mental activity allowed him to learn things quickly and have meticulous and active thinking.
This also made him proficient in almost all the high-difficulty acts in the circus.
Walking on a tightrope, knife throwing, underwater escape, firearms, flying knives, flying cards...
"Lockpicking" was a compulsory skill for underwater escape.
But that mental strength also troubled him.
He couldn't feel normal emotional fluctuations, like joy.
This made him increasingly seek thrills before crossing over.
Using sensory stimulation to find some way to solve his mental confusion.
...
His thoughts flew for a moment and then returned.
Ji Xun opened the safe and took out a stack of documents.
The contents were messy, seemingly having been searched before, with some parts missing.
The mechanical-arm girl also leaned over, and the two were drawn in by what they saw.
"Empire Calendar, May 3, 1141, unsealing of 'S-level Catastrophe Source,' research begins."
"1001 Experimental Room, Subject #1144's extraordinary ability has evolved again, showing extremely high resistance to dark elements... injected with ten times the dosage of 'Heim VII Ash Serum,' the body's resistance continued to increase, and after five days, an unknown direction mutation occurred... Conclusion: This source card has S+ level dark element affinity growth."
"1099 Experimental Room, Subject #815 attempted to implant the polluted limb [Giant Muscle], and the serum induced a surge in strength, with the body attributes miraculously surpassing the limit without a job change, but the subject lost sanity... mutation became uncontrollable after 14 days and died on the same day. Conclusion: The catastrophe source has extremely high growth potential for strength."
"2012 Experimental Room, Subject #549 attempted fusion, causing mental mutation, suggesting continued observation... after seven days, the mutant evolved into a B-level calamity [Fallen Witch], possessing extreme charm abilities... Conclusion: This catastrophe source has very high growth in mental aspects, continue research in this direction... the subject's mutation state stabilized, and after the sixteenth injection of T3 serum, a second mutation was successfully induced, evolving the subject into an A-level calamity [Fear Witch], Conclusion: The catastrophe source has growth potential."
"3045 Experimental Room... the subject mutated into an A-level mystical calamity [Curse Gambler], death by curse..."
"4011 Experimental Room... the subject mutated into an A-level assassin-type calamity [Shadow Stalker], hiding in the shadows..."
"Summary Report: After fusing with the catastrophe samples, each subject awakened different talents. So far, thirty-one unique talent growth directions have been confirmed... it has been confirmed that this catastrophe source is an epic source card unprecedented in history. Preliminary conclusion: Fusion with this card requires extremely high basic mental strength, dark affinity, manic psychic energy... and other yet-to-be-identified conditions."
"Research Institute Suggestion: The current probability of fusion leading to mutation is 100%, with risks of external pollution. It is suggested to change the sealing level from 'S-level' to 'T-level' and permanently seal it."
"…"
This was the crucial clue Ji Xun was looking for!