Grey City (1)
"What the fuck… is that thing?"
Sehyun stared at the monster, his mouth falling open without thinking.
Black clothes. A shape roughly human, yet nothing on it that could be called a face. No eyes, no nose, no mouth — only a blank white head. Was that slow-moving something another anomaly, the same as the Red Classroom?
If so, there would be rules this time too.
Sehyun glanced sideways at Yui. She had clamped a hand over her mouth, trying not to make a sound, and was looking right back at him. Even her footsteps were careful. Sehyun followed suit, muffling every step as best he could.
Yui raised her left hand. A signal: keep moving.
Moving — but where? How far until they were safe?
…Thinking about it wouldn't produce an answer. This wasn't a matter of being smart or stupid. Even the greatest detective couldn't reason without information. Right now, they knew exactly one thing about that creature.
It was a disgustingly shaped monster.
Should they risk danger just to learn more? He didn't know. If they could run without fighting, that would be best.
What if this is a fully sealed space, like the classroom?
Following Yui's hand signals, Sehyun edged slowly away from the monster and scanned their surroundings. A city drowned in fog. No people, no car engines, no other signs of life. It felt as if they had stepped into a completely isolated space.
Then the goal this time is to escape this place too.
Another question followed immediately.
How?
In the classroom, at least, there had been a condition: find the real Yui. This time there was nothing. Once had been more than enough. Getting dragged into an anomaly twice in a single day — his resolve was already starting to crack.
But he couldn't stop thinking. The moment he stopped thinking might be the moment it truly ended. Yui would be the same.
First: gather information. Avoid dangerous moves as much as possible and observe carefully. Humanity had survived this long because people could observe and reason. At least, that was what Sehyun believed.
Yui's ability was a Status Window, she'd said. Could that Status Window show information about the monster too?
He looked over at her with a flicker of hope. Yui glared back as if to ask why he was staring. Sehyun pointed at the monster with one finger, then pointed at her.
Know anything?
That was roughly what the gesture meant. Yui furrowed her brow. She hadn't understood.
The monster clearly had no ears. But the absence of visible ears was no guarantee it couldn't hear. Sehyun bent down, picked up a small stone from the roadside, and tossed it lightly in the opposite direction from the creature.
Click.
The stone skittered across the asphalt. The monster didn't react.
So it didn't respond to simple noise? What about a human voice, then?
Sehyun whispered as quietly as he could.
"…Know anything, Yui?"
Yui flinched hard and stared at him. And the instant Sehyun spoke — the monster's head tilted, just slightly. That blank white face turned toward him.
Both Sehyun and Yui froze. The monster had only turned its head; it didn't move any further.
Yui clenched her teeth and spoke in a tiny voice.
"Since you already talked, that's the end of the voice experiments."
"Nothing on the Status Window?"
"Nothing."
Yui answered without taking her eyes off the monster.
"To see information in the first place, there has to be interaction with the target. Right now there's nothing between me and that thing."
"So to get information, we'd have to interact with it directly?"
"Not necessarily… but if we can't learn anything any other way, then yes — as a last resort."
A last resort. That was how she put it. Sehyun thought it felt a little like calling for a hint at an escape room café. Except this wasn't a game. There was no telling what they'd have to give up in exchange for a hint.
"Before that, let's check a map."
Sehyun pulled out his phone and opened the academy's dedicated map app.
"So we're around…"
"Hey!"
The second Sehyun glanced down at the screen, Yui shouted.
"Huh? Why— aagh?!"
Before he could even lift his head, Yui's foot slammed into his side. Sehyun's body rolled sideways.
"Oh, fuck…!"
He scrambled up — and the monster was standing right in front of him. Barely a step away, one arm stretched forward in an awkward reach, as if it had been about to grab him a moment ago.
But the instant Sehyun looked at it — the monster's movement stopped completely. Like a frame of a charging video paused mid-lunge.
"You idiot!"
Yui swung wide around the monster and ran to him.
"I told you to watch it!"
"You didn't say it out loud!"
"If I say it out loud, it reacts!"
She was right. Sehyun had nothing to say back.
Yui scanned the situation fast. The monster was still frozen in the direction Sehyun was looking.
"Sehyun. Keep looking at it for a second."
"I am looking. Now what?"
"We're splitting up."
"What?"
"It just reacted to your voice and tried to attack you. There's a high chance you're the target."
"'High chance' is the scariest phrasing you could use."
"Because it isn't confirmed yet."
Yui held out her hand.
"Give me your phone."
"Why?"
"I need the map. Unlock it first."
Without taking his eyes off the monster, Sehyun unlocked the phone with one hand. Yui took it and pressed her own phone into his palm instead.
"You know my number, so you can call from your phone. Mine's unlocked."
"Wait. So I'm supposed to run while holding your phone?"
"Answer when I call. I'll watch the map and move."
Yui dialed her own number on Sehyun's phone as a test. The phone in Sehyun's hand buzzed briefly. Connection worked.
"Good?"
"Yeah, but… you're staying alone?"
"Better than both of us getting chased."
Yui glared at the monster.
"And what we need right now isn't both of us seeing the same thing — it's gathering information from different positions."
Sehyun couldn't answer. Logically, she was right. Emotionally, he hated it.
"Get as far as you can. Check behind you in between — every time."
"And you?"
"I'll check whether it switches targets. Answer the second I call."
Yui shoved him in the back.
"If you get out, meet at the dormitory."
"Hold on—"
"Go!"
Sehyun started running on the momentum of the shove. A run with no destination and no goal. He didn't know where to go, how fast to run, or how long he had to hold out. It was an endurance match in the purest sense.
Unfortunately, it was still too early for Sehyun to feel true despair. Real despair arrived the moment he looked back after running with his eyes fixed forward.
The monster was standing right behind him. Roughly five meters. Frozen mid-run, like a paused clip of a track athlete.
"…Fuck!"
It had definitely been much farther back a moment ago. He hadn't heard footsteps. Yet the second he turned around, it was right there.
Sehyun faced forward and ran again. Five steps. Ten. He looked back. The monster was stopped about five meters behind him again — in a different running pose than before.
It freezes when I'm looking at it.
He turned forward again.
And it moves while I'm not looking.
Then all he had to do was keep his eyes on it. But he couldn't run while looking backward. Every time he twisted his head, his breathing broke. His steps grew heavier. He couldn't last long like this.
"Fuck, anything…"
Through the fog, a bike rack came into view. With people gone, several bicycles still stood there. Sehyun grabbed the one in front — unlocked.
"I'm saved!"
He swung on and pedaled. Far faster than running, and it spared a little stamina. Even so, he still had to glance back every few seconds. The moment it entered his vision, the monster stopped. Putting enough distance between them to vanish completely into the fog made no difference. Look away, check again a moment later, and it was nearby once more. Always outside his field of view.
Sehyun's figure vanished completely beyond the fog. Yui slowed her steps.
As expected, the monster had gone after Sehyun alone. That meant there were conditions for selecting a target.
When they first spotted the monster, nothing had happened. Same when the two of them tried to slip past quietly. Then Sehyun had spoken. That was the moment the monster turned its head toward him — and the moment Sehyun looked down, it attacked.
Does it lock onto the first person who makes a sound?
The simplest and most plausible hypothesis. Yui had spoken afterward too, but the monster had followed Sehyun. Maybe once a target was set, other voices were ignored. Or maybe only Sehyun's words had registered as interaction directed at it.
Even in the moment the monster reacted to Sehyun, nothing had appeared on Yui's Status Window. That meant no interaction had formed between her and the creature. Of course, that alone couldn't prove the rules. It was only the most plausible hypothesis among the clues they had.
If something looked like an exception to the rules, it meant they hadn't found all the rules yet. That was how Yui thought.
"The problem is how long he can hold out…"
Sehyun's running form wasn't bad. But he didn't have a body built for long all-out sprints. He would need a way to catch his breath in between. And if the monster really was a creature that moved by slipping out of sight — Sehyun had probably already figured that out. He wasn't the type to just run in blind panic. Even in the classroom, he'd found the real Yui with limited clues. Even while being chased, he would try to confirm the rules.
"So what I need to do now is…"
Yui checked Sehyun's phone screen. Fortunately, the map app was still open. Current location. Surrounding roads. Paths leading to parks, the downtown area, the lake. She zoomed in and out, committing the local terrain to memory.
Then her own number caught her eye in the recent call log. Yui hit the call button at once. The line connected before the second ring.
"Hello?"
Sehyun's voice came through. Calmer than she'd expected — though the harsh rush of wind came with it.
"You okay? Still running?"
"No. Bike now."
"A bike?"
"If it's a city where only the people are gone, the vehicles are still here, right?"
Yui was briefly speechless. He hadn't clung to running — he'd immediately used the resources around him. The title of Hero clearly wasn't pure bluff.
"Nice work."
"Save the praise. I figured something out."
"Tell me."
Sehyun steadied his breathing, then said:
"It freezes when I'm looking at it."
"And when you're not?"
"It moves. More precisely — it closes in while I'm not looking. No matter how much distance I put between us, it shows up nearby again."
"Where does it appear?"
"Always outside my field of view. I checked three times."
Three times. Hard to write off as coincidence.
"I've been thinking about the targeting condition too."
Yui laid out her hypothesis: that the monster had first reacted to Sehyun's voice; that it hadn't switched targets even after she spoke; that it seemed — still unconfirmed — to lock onto the first person who made a sound.
Sehyun was quiet for a moment.
"…Sounds plausible."
"Plausible is all it is. Don't go talking to it just to check."
"I'm not that crazy."
"You seemed a little crazy."
"Is this the time for jokes?"
Through the phone, she heard Sehyun pedaling harder.
"So what now?"
"I'll check the surrounding map more carefully."
Yui looked at the map again.
"Keep noting any buildings or signs you pass so we know where you are. If a road dead-ends or gets blocked, tell me right away."
"Got it."
"Conserve stamina as much as you can. Checking behind you too often will wear you out fast."
"If I don't look, that bastard comes closer."
"Exactly — so you need to figure out how often is safe."
Sehyun gave a short laugh.
"Easy to say."
"Risking your life on the ground is the Hero's job, isn't it?"
"Then what's the Saintess do?"
"Think from the back."
"Sounds like a pretty cushy role."
"If you've got a problem with it, switch."
"No thanks. You'd outrun me by a mile."
"Wise choice."
The brief banter ended. Silence settled between them for a moment. The fact that the monster was still chasing him hadn't changed. But just knowing he wasn't alone steadied Sehyun's breathing a little.
"I'll check the map and call you back."
"You're hanging up?"
"Staying on the line just drains the battery. And you need to hear what's around you."
She was right.
"Okay. Call soon."
"Don't die."
"You neither."
The call ended. Sehyun gripped Yui's phone in one hand and the bike's handlebars in the other. Then he looked back again.
The monster was frozen about ten meters behind him, still in a running pose.
He'd figured out how it chased him. He'd figured out how to stop it.
The problem was —
he still had no idea how to end the pursuit.