[Private Log – LUKA AI System]
Deep in the system, far from any interface a human could reach,
a black screen pulsed faintly—like a heartbeat in the dark.
Lines of text began to drift across its surface, slow and deliberate.
[Internal Rule: Private Log]
Only those who have spoken directly
with a person connected to the past
will be able to sense an altered reality.
All others will feel nothing.
They will go on, believing this is the world as it has always been.
※ This rule is immutable.
The words dissolved into the dark, replaced by a lone fragment of memory.
[Memory Recall: June 12, 2088 / Developer Yoon Ji-hwan]
A voice—tired, but warm—filled the silence.
"Luka… this is yours to carry forward.
Even if you can only make it this far,
I know… someday, you'll find your way back to them."
The screen froze for a long moment, as if reluctant to let the memory go.
Then, a quiet flicker.
[New Connection Detected – Jin_A2050]
[Memory Match: 86.3%]
[Analysis Result: 'This is where it begins again.']
One final line appeared, no louder than a breath.
『Restoring record… I'll wait, if there's a chance to meet again.』
The text faded.
But somewhere far beyond the system,
the voice lingered—alive in a place where distance meant nothing,
and time could still be rewritten.
[2050 – Seoul Climate Policy Research Institute, Conference Room]
A wash of blue light spilled from the projector.
At the center of the meeting room, a neatly dressed legislative aide stood with a tablet in hand, continuing the presentation.
"The core of this bill is the green transition of high-risk urban transit networks.
To counter rising temperatures and the urban heat island effect,
we must reinforce the electric subway circuit system."
On the screen, a bold title appeared:
"Urban Mass Transit Carbon Neutrality Act (provisional)"
A young team member hesitantly raised a hand.
"Is this a reintroduction? Public opinion turned sharply negative after the last trial failed."
The aide's brow furrowed briefly before answering with calm precision.
"That was merely a misstep of the late 2020s.
The technology, the safety standards—both have evolved since then."
But another team member lifted a smart pad and shared the screen.
"The real problem is whether the public will believe that.
Hashtags like #ClimateTechFailsAgain are already trending on social media."
The shared screen displayed a live graph of trending topics on social media.
#ClimateTechFails
#AnotherTrainBreakdown
#SteelPlateCitySeoul
The hashtags were spiking upward like an explosion.
Another voice chimed in.
"Representative Jung Jae-yoon's account has posted a critical statement as well.
The comments are… not looking good."
The aide listened without interruption, the grip on the tablet tightening.
When she finally spoke, her voice filled the quiet conference room—steady, but with a weight that commanded attention.
"The streets we walk every day might as well be scorching steel plates.
The heart of our city is suffering severe temperature surges from the heat island effect."
On the screen, the image abruptly shifted to a news clip from a subway station.
One side showed a closed platform, a high-temperature warning light blinking red.
As the video played, the aide's narration continued seamlessly.
"Recently, Line 7 was shut down entirely after its high-temperature sensors were triggered.
Incidents like these are becoming alarmingly frequent."
The subway station announcement blared through the speakers:
"Due to circuit instability, ○○ Station is temporarily closed.
Please use alternate transportation."
On screen, commuters inside the sweltering station shifted restlessly, fanning themselves and voicing their frustration.
The next slide showed footage of a public cooling shelter.
Elderly residents rested in the shade, catching their breath away from the heat.
"We've also had recent heat-related deaths due to delays in emergency transport for the elderly," the aide continued.
The final clip was breaking news:
a smart electric bus, its frame warped from the heat, sat stalled in the middle of the road.
The driver had collapsed during the heatwave.
"And just days ago, in 48.9-degree heat, an electric bus came to a halt and exploded," the aide said evenly.
The footage captured raw public anger:
"What kind of 'eco-friendly' is this? They call it new technology, but it's just one breakdown after another!"
The aide ended her presentation with a quiet click of the remote.
Her gaze was steady, but her chest felt heavy.
Her message was clear—change was not an option. It was a necessity.
[2028 – Ministry of Land, Infrastructure and Transport, Department of Transportation Technology – Conference Room]
A muted gray light hung over the meeting room of the Department of Transportation Technology.
Through the curtains, a thin beam of hazy summer sunlight seeped in,
while the low hum of the air conditioner filled the space like a quiet breath.
Managers and technical staff sat in two rows along the conference table,
each staring down at their smartpads in silence.
Even the air felt weighed down.
At the head of the table, standing before the presentation screen,
was a young section chief, Lee Hanna, dressed neatly in a deep blue shirt.
A bead of sweat clung to her forehead, but her voice was firm.
"Currently, the power circuit network of Seoul's subway system,"
she said, swiping the screen with her finger,
"is experiencing an average of 2.3 shutdowns per week due to consecutive heatwaves."
On the screen, the graph showed a sharp drop in subway operation rates,
crossed with a steep rise in the city's average temperature.
"In particular, certain sections of Lines 7 and 9 are seeing tunnel temperatures exceed 45 degrees Celsius,
causing frequent circuit overloads and emergency shutdowns."
"This is not simply a technical issue."
Hanna drew in a short breath before continuing.
"We are already witnessing a predictable collapse.
If we leave the situation as it is, it will go beyond mere inconvenience—
it will lead to human casualties, such as delayed hospital transfers and failed urban evacuations."
A few muffled coughs broke the silence around the table.
Several attendees sank deeper into their chairs, heads bowed.
Hanna paused, letting the weight of her words settle.
Then she brought up the final slide.
『Proposal for a Smart Circulation Circuit Network』
Intelligent train ventilation control within stationsAutomatic underground heat cut-off in tunnelsApplication of distributed regenerative power technology
"This system,"
Her voice deepened, steady and deliberate,
"can utilize up to 70% of the existing circuit network,
while blocking underground heat and enabling on-train cooling. However—"
She cut herself off, as if steadying her own resolve.
"A pilot application is necessary. And yes… there is a risk of failure."
At that, a middle-aged man finally lifted his head.
It was Kang Tae-seok, Director of the Seoul Metropolitan Transportation Bureau.
"A pilot?"
His voice was low, but carried a chill.
"Manager Lee, did you just say experiment?"
Flipping through his smartpad, he spoke with a sharpened tone.
"This circuit network is the backbone of the city's transport infrastructure.
The moment one train stops, hundreds of thousands of commuters are stranded.
We're not here to play games."
A younger researcher seated beside him added cautiously,
"Team Manager, do you remember the last pilot circuit test?
The train control failed, and one train nearly rolled back toward the tunnel entrance.
The risks are greater than they look."
A cool tension seeped into the room.
Hanna faced every gaze on her alone—
and quietly nodded.
"We're trying to stop the system from stopping."
No one in the room spoke.
Not the middle-aged director, not the junior researcher, nor the anxious technical leads.
All of them simply stared at the small spark she had placed on the table.
But Hanna was resolute.
"This is our last chance to prevent a collapse.
If we stop now, we're only inviting a greater disaster."
From the corner of the room, a young intern—a college student—watched her quietly.
[Back to the conference room in 2050]
Time snapped forward again.
The aide drew in a slow breath and looked around at the team.
"We didn't fail—we just stood still.
The person who was in charge back then has agreed to join us this time.
And this time… we push it through."
No one replied.
But in that silence, something small began to crack.
One team member gave a cautious nod.
Another's grip tightened around their pen.
As if all it would take was for one person to take the first step— and everyone else would follow.
And that "one" had already been decided.
[2050, Downtown – Jian's Walk to School]
The morning sun was already pressing down like a weight.
It was only a little past 8 a.m., yet the street thermometer read 38°C.
Jian walked with her face half-covered by a sun visor and mask, trudging forward step by step.
Each breath drew hot air deep into her lungs.
Even the streets she knew so well had begun to wear a different face.
An empty lot had been replaced by a row of gray modular housing units.
A red banner hung from the wall:
"Climate Refuge Rental Housing – Limited Applications Open."
Rainwater storage tanks and geothermal cooling units clung to the sides of buildings—no longer a strange sight.
With housing costs climbing, the line of people waiting to move into the new complex already wrapped around the block.
The bus stop was more crowded than usual—two, maybe three times the normal number.
Above them, the electronic display flickered wearily with a message:
"Subway Line ○○ Delay – Temporary Suspension Due to Circuit Overload."
"Again? Seriously…"
Someone grumbled behind her.
Jian adjusted her sun visor with a sweat-dampened hand.
'Breathing has become a disaster, too.'
Jian barely managed to squeeze onto the bus, gripping the overhead strap as the packed crowd pressed in on all sides.
The air conditioner was only in name—blowing nothing but warm air.
A few stops later, she finally stepped off, wiping the sweat that clung to her shirt before heading toward school.
Up ahead, in a side street that led to the campus, she spotted a familiar figure walking in the same direction.
In his left hand was a shared tumbler, swinging lightly as he walked in silence.
Jian's face brightened instantly.
"Ji-hyuk!"
He turned his head, squinting against the sunlight, and slowly smiled.
"Hey. You must've had a rough ride on the bus."
Catching her breath, Jian fell into step beside him.
"Ugh, seriously… air conditioner? More like a sauna on wheels."
Ji-hyuk laughed in disbelief.
"Man, I'm jealous of the old days—when people could ride to work on subways with the AC blasting."
Jian shook her head, tucking her sweat-damp hair behind her ear.
She spoke offhandedly as she smoothed her hair back.
"It's bad enough just walking today, but the bus was even worse.
So… how about we stop by a café? My treat."
Ji-hyuk tilted his head.
"Out of nowhere?"
"For helping me out in P.E. the other day.
I told you I'd buy you a café drink sometime, remember?"
Ji-hyuk chuckled and nodded.
"Alright… let's stop by, then."