Transmigrated as The Forgotten Extra-Chapter 132 Awakening from Slumber.

After waiting for a while, the rumbling engine of the Humvee that echoed throughout the room finally fell silent. Cain immediately told Rika and Louise to move away from the door.

The two girls stepped back at once, their gazes fixed outward. But a few seconds later, the thick stone-plated iron door slid shut, sealing the room completely and cutting Cain off from the outside world.

Rika and Louise walked past the vehicle Peter and Abel had driven, stopping near Luna, who stood not far from Cain’s side.

The thud of the car door closing drew Cain’s attention to Peter and Abel as they approached. He turned his head slightly and saw Luna chatting casually with Rika and Louise. The boy let out a long breath, his twitching fingers slowly regaining their strength.

Though his entire body still ached, it was nowhere near as bad as before, when he had needed to lean on Luna just to stand.

Now, at the very least, he could walk on his own.

"So, what do we do now?"

A gentle voice came from beside him, making Cain turn to see Luna and the other two girls staring at the iron door at the far end of the room.

He paused, touching his chin as he sank into thought. Cain exchanged glances with the girls and with the boys standing nearby.

"Let’s explore this place first. Who knows, there might be something useful here."

"Alright."

All five of them answered at the same time, their voices overlapping and echoing through the vast space before fading away like whispers from the past.

Cain nodded. Lifting his heavy legs, he moved toward the door at the far end of the room.

The silence that ruled the place made every step he took echo in every corner. His black eyes swept through the interior, catching reflections of his own shadow on the gleaming silver walls.

A question suddenly surfaced in his mind.

’How can ruins that have been abandoned for so long still be this intact?’

’This makes no sense.’

Just like the hidden ruins Cain had encountered during his first mission, this place was spotless, without even a speck of dust daring to intrude and disturb the sterile calm inside.

Instead, it was Cain and his group who had brought contamination from the outside into this pristine space.

That much was evident from the small panel still appearing at the edge of his vision. However, its appearance had slowed considerably, unlike outside, where it would pop up every second.

[Corruption +1%]

...

Even while suffering backlash for overusing his skill, his body greedily continued to absorb the cosmic virus lingering in the atmosphere.

Setting that aside, Cain focused his eyes on the door before him.

’Scan Protocol!’

His black pupils shimmered, turning a bright blue as he stared at the floating notification panel blocking his view.

[Scan Protocol activated.]

[Elevator: ... status: still active]

[...Access Code: 050532]

Cain shifted his attention to the side. A small device was attached right next to the iron door.

He stepped closer, examining the numbered buttons and command keys such as Enter, Cancel, and the like.

Without hesitation, the boy pressed Enter first.

Beep.

The device booted up, glowing red briefly before turning green.

His eyes flicked back to the floating panel, and Cain’s fingers began typing in the displayed numbers.

’050532, and Enter!’

Immediately afterward, a hissing sound echoed as white mist poured out when the door opened, releasing a cold gust of air that brushed against his unguarded cheek.

The silver-haired boy stepped inside. Within, he saw a long monitor panel lining the side of the door, along with several buttons indicating the available floors.

"What floor should I pick?"

Cain frowned, holding his chin. By then, the others had entered the elevator as well, yet there was still plenty of space left.

Silence descended upon the confined area.

Aware of how quiet everyone had become, Cain glanced over his shoulder and asked,

"Any requests? Where do you want to go?"

Instead of an answer, the four of them exchanged looks, then shook their heads with resigned sighs.

Rika stepped forward, crossing her arms over her chest.

"Listen, Cain. How are we supposed to know where to go when all of this discovery and opening the entrance door happened because of you?"

The silver-haired boy raised an eyebrow. Behind her, the other three nodded deeply.

"So if you’ve already decided something, then just do it. As long as it’s not dangerous, we’ll follow you, understand?"

Rika tapped the visor of her helmet, her shoulders slumping.

"Please don’t ask pointless questions like that again. Geez."

"Alright, sorry."

Cain waved his hand dismissively and turned back to the long monitor displaying the building’s structure, partially obscured by massive rock formations.

’Huff, I was just trying to lighten the mood, and I got scolded instead...’

He let out a short sigh, though he couldn’t hide the faint smile tugging at his lips as Rika returned to her usual sharp demeanor.

’Welcome back, cranky vice-leader.’

Putting aside the jokes in his head, Cain carefully read through each floor, from the top to the bottom.

’The upper floors are for overseers. The second floor is a lab. Floors three, four, and five are the cafeteria and rest areas. And the basement stores a large volume of water.’

Cain pressed the button that would lead him to the basement. He wanted to confirm whether the water he was looking for was truly stored there or whether it was usable.

The doors hissed as they slid shut.

Cain’s pupils shrank as his breathing slowed, even becoming labored. His ears started to ring, as the air suddenly felt incredibly thin.

’What happened!?’

The white lights illuminating the elevator dimmed as the machinery began lowering the spacious chamber.

A momentary sense of weightlessness enveloped Cain’s body. His left hand immediately gripped the katana at his waist, ready to slice open the elevator doors if this was some trap meant to suffocate him.

After several tense seconds, the lights flared back to full brightness, and oxygen rushed into his lungs once more.

Cain turned toward his companions, but they stood stiffly, dazed, lost in thought about their destination.

None of them seemed affected by the earlier disturbance; perhaps their armor suits supplied oxygen reserves unlike Cain, who was breathing the outside air directly.

Whatever the case, something else immediately caught his attention.

The small panel displaying corruption points had disappeared.

That meant he and his companions had entered a safe zone free of the cosmic virus.

Still, Cain chose not to tell them just yet. His credibility was low, and for now, his priority was the main issue: water.

Moments later, the elevator slowed to a stop, chiming softly with a pleasant ding.

The doors slid open slowly, as if unveiling a new path before them, revealing a hidden world supported by rows of iron pillars forming a massive foundation holding everything above.

"Whoa, look at that!?"

Abel’s cheerful voice snapped Cain out of his thoughts as he followed the blond boy’s gaze.

"No way, is this?"

Rika asked softly, disbelief thick in her voice as she stepped out of the elevator.

Louise and Peter exchanged looks before stepping out together, followed by Abel, who jumped lightly and landed on sturdy marble flooring bordered by iron railings stretching on both sides.

Cain swallowed, moistening his dry throat. He stepped out, his eyes unable to tear themselves away from the enormous reservoir spreading out on both sides.

Light shimmered across the water’s surface, causing Cain’s lips to curve upward. He moved closer to the railing, his right hand gripping the cold iron, slightly damp from condensation clinging beneath it.

"So clear," Luna murmured beside him.

The grey-haired boy stared intently at the water, noticing a gentle current flowing toward the far left, where a tunnel extended into the unknown.

’So that’s why the water’s still clear, even after all this time.’

Stagnant water left untouched for too long, especially for centuries, would be incredibly dangerous, becoming a breeding ground for bacteria harmful to humans.

While the others remained focused on the water, listening to its mesmerizing flow, something none of them had ever seen before.

Cain’s ear twitched, hearing a mechanical sound like a computer running. He took a step back and turned his head, searching for the source.

His body froze instantly, stiff as a statue, when he spotted a massive computer standing not far from him, its giant monitor glowing.

On the screen, thousands of numbers and words clashed chaotically in the form of data in constant motion.

Like a moth drawn to light, Cain moved toward it. He stopped directly in front of the enormous monitor, and his eyes widened.

’Don’t tell me... this thing has been active for centuries?’

Once again, he stared at the endless data streams overlapping and shifting, so overwhelming that his skull throbbed from the sheer volume of information.

He blinked several times, lowering his head as he exhaled softly.

’How is this possible?’

Without any conscious command, Cain’s pupils glowed blue, a sign that one of his abilities had activated.

In an instant, the dizziness assaulting his head vanished, replaced by a panel displaying detailed information about the object before him.

[Main Computer: A.R.C.H.E.S.]

(Autonomous Regulation & Cleansing Hydrological Ecosystem System)

[...]

[...Access Code: "A river never returns to its source."]

Cain blinked as the panel disappeared. He shook his head, letting out a long sigh.

’This damn system of mine...’

He wanted to curse, but it was pointless. This wasn’t the first time his system had acted on its own.

Taking a deep breath, the boy looked up at the massive monitor and spoke aloud.

"A river never returns to its source."

A panel appeared on the screen, typing in the access code he’d just spoken.

Suddenly, all the data shifted aside, as if parting to reveal something hidden within.

An interface appeared, followed by an emoji with a flat expression. Then, its eyes widened as it locked onto Cain.

The emoji spoke.

{Welcome. My name is ARCHES. It’s a pleasure to meet you.}