As Daniel and I switched places, the herd of fish-headed creature mirrored our every move, keeping the same disturbing formation, always circling us.

But that was all they did. No attacks, no sudden movements.

I thought about firing a shot, but there was no telling what would happen if we broke the silence. What if they snapped?

Back in the sewers, it had been just one fish-headed guy. Between the two of us and our guns, we barely managed to kill it, and that was with heavy fire.

But now, there were twenty-five. Maybe even more.

If they rushed us, Daniel and I wouldn’t stand a chance.

We'd end up as fish bait.

I glanced over at Daniel. He looked like he was going to crack any second, his eyes darting between the fishmen. His body was rigid, and sweat was starting to show through his shirt.

"The contamination level’s at 79 now!" Daniel blurted out, his voice high-pitched and tense as he scanned with the contamination meter.

I still didn’t fully grasp what those numbers meant. Every time the contamination level rose, I felt… nothing.

Daniel, noticing my lack of reaction, tried to explain, "A Class D contamination zone is anything between 60 and 90."

So, when we first entered, it was 55%, which meant we’d been in a Class E zone. But now… it was worse.

"What do we do now?" Daniel’s voice wavered, his eyes pleading. "Shoot our way out?"

"Ignore them," I said, my voice steady.

"Ignore them?" Daniel shot me a look like I’d just lost my mind. "Are you serious?"

I shrugged. "Yeah."

Daniel was incredulous. "How are you this calm?"

I remembered the questions Emily asked me when I first joined.

1. Are you afraid of monsters?

2. Are you afraid of corpses?

Her focus was on fear, but my answer to both had been simple: No.

And now it made sense to me. Why my mental value was 100. Because I genuinely wasn’t scared. These things? I didn’t even see them as monsters.

Daniel stared at me, waiting for more of an explanation. I simply said, "Ignore them. If you don’t let them get to you, they can’t contaminate you."

He blinked at me, bewildered. "How do you even do that?"

I sighed. "Just… think of it this way. Mental contamination doesn’t come from fear itself. Blood, corpses—they just make you scared. But that’s not contamination."

He looked even more confused.

"It’s when something looks almost human but starts doing something that completely messes with your head. Like… imagine a fishman sitting on a train, doing nothing but staring at you. They’re doing something *normal*, but the fact that they’re abnormal… that’s what gets to you."

Daniel looked at the twenty-five fish creatures surrounding us, panic evident in his eyes. "So, how the hell am I supposed to ignore this?"

I glanced at him, then back at the monsters. "In my head, they’re just rotten fish."

Daniel choked out a disbelieving laugh. "Rotten fish? You’re in a goddamn seafood market right now?"

I gave him a small, crooked smile. "Something like that."

"Unbelievable," he muttered. "You seriously act like you don’t give a shit."

"Don't look at them," I suggested, turning away from the herd. "Talk to me. Focus on something else."

Daniel swallowed hard, his eyes still darting around nervously, but he managed to ask, "What should we talk about?"

"Why did you come up here?" I prompted, hoping to pull him out of his fear.

"Following company protocol," he muttered, trying to look anywhere but at the herd of monsters.

Cleaner Code of Conduct.

Rule No. 4: Stay with your team.

Rule No. 3: Wait for rescue.

When the rules conflicted, Daniel had to make a choice.

But we weren’t really getting into anything deep. Daniel shot the question back at me. "What about you? Why’d you come up?"

"Our job is to clean up trash," I replied.

Daniel blinked, looking even more confused. "And?"

"We get paid based on how much trash we collect."

"Darling, now it's not a good time for crash course, or Cleaner 101. I don't need a lecture..."

I cut him right there, "we were already stuck in a contamination zone. And right next to us? Another zone filled with spores. If we were already here, risking our freaking lives, why not get paid for it?"

"No way," Daniel muttered, staring at me in shock. "You're actually… you are some sort of freaking workaholic?"

"I’ve only been on the job for two hours," I said with a shrug.

"Two hours," he repeated, shaking his head. "You’re something else, Nina."

Daniel seemed to be processing the insane logic I’d just laid out for him. As he stared at the fish-headed guys, something shifted in his eyes.

You could be reading stolen content. Head to Royal Road for the genuine story.

Did I just see a dollar sign?

Daniel muttered, "So these weren’t terrifying creatures. They were… profits?"

Twenty-five fish. Twenty-five potential bounties. That could easily translate to a quarter-million credits.

These rotten fish now looked as if they were gold.

"Daniel," I said slowly, "do you think… we could mentally contaminate them?"

"Wait, what?" Daniel blinked again, clearly not keeping up. But I could see the curiosity there. "How… how do we even do that?"

I thought for a moment. "Mental contamination happens when something that looks normal does something bizarre, or something bizarre behaves normally. The key element is repetition."

That’s how contamination worked. The first fish-headed guy had been repeating the same murmur about missing the last train. The ones that kept boarding the train did so repeatedly, too.

So here it is. The formula.

Repetition + abnormality = mental contamination.

For the first time, Daniel and I weren’t just cleaners blindly following orders. We were breaking down the logic behind contamination.

"Yeah…" Daniel said slowly, piecing it together. "That actually makes sense."

I raised an eyebrow at him. "Got anything on you that might be mentally disturbing?"

Daniel thought for a moment, then pulled out a small device. "I, uh, brought a cookbook."

I stared at him. "A cookbook?"

Daniel met my gaze and shrugged. "You know, just in case this gig doesn’t last forever. Gotta have a backup plan."

Cleaners didn’t have long careers. Once they earned enough, they retired—but spent the rest of their lives undergoing mental evaluations. Maybe one day I’d be in that position too.

Man, cleaning up trash really sucked.

"Read something," I said, deciding to roll with it.

Daniel flipped through the electronic cookbook, found a recipe, and cleared his throat. "Here we go. ‘Pan-fried carp. First, make crosshatch cuts on the fish, add salt to the oil, and fry on low heat until golden and crispy…’"

"…"

The fish-headed guys stood motionless.

"…"

Daniel was seriously reading a recipe for cooking fish.

I quickly activated the recording function on my helmet. Both our helmets had external speakers, so I amplified the sound.

Daniel handed me the recipe file, and I joined in, deadpan, as if this was just another day at work.

Two helmets, two voices, reciting a recipe for fried fish at full volume. I even added a playback loop for good measure.

If someone were to board the train right now, they’d walk in on the strangest scene imaginable.

Two "bikers" dressed head to toe in black leather, wearing full helmets, standing side by side… loudly reciting a recipe for pan-fried fish.

On repeat.

Unsettling? Definitely.

Repetition + abnormality = mental contamination.

Twenty-five fish-headed guys, once so hostile and full of malice, were now visibly confused. Their stances softened, their movements slowed.

After repeating the recipe about ten times, Daniel’s contamination scanner beeped.

"Wait… did the contamination level just drop?" His voice was incredulous. "It’s down to 78. It actually worked!"

I nodded, satisfied. "Keep reading. I’m going to find the contamination source."

Daniel kept reciting the fish recipe like a human loudspeaker while I got to my feet and started searching the train.

The contamination source had to be here somewhere.

As I moved through the train, the fish herd stayed put. They held onto the rails, their grotesque bodies covered in scars and punctures, but none of them followed me.

It was like the mental contamination had short-circuited them.

Daniel continued reciting the recipe, his voice filling the train as I walked. The train only had four cars. I moved methodically through each one, searching for clues.

Car 4 had three passengers. Car 3 had two. Car 2 had five.

Car 1, where we had started, had the most—twenty-five fish-headed guys, plus us.

Something had definitely gone wrong on this train.

The System had mentioned the disappearance of the last train on MetroLine One. What had caused it to vanish? Contamination?

If contaminants could cause mental contamination, did that mean their formation involved some kind of psychic force too?

Like… resentment?

Ding-a-ling-ling—

The sudden ringing of a phone snapped me out of my thoughts. It was coming from Car 3.

I ran to check it out. A phone was lying on one of the seats. I was sure I hadn’t seen it during my earlier sweep of the train.

Where had it come from?

Someone was calling the phone.

The device was old, ancient by modern standards—a touchscreen model from at least eighty years ago. In this post-apocalyptic world, technology had evolved far beyond that. Most people had neural implants now, integrated with secondary brains used for identification, communication, and financial transactions.

No one used phones anymore.

"A passenger’s forgotten phone?" I muttered to myself.

Daniel glanced over, his eyebrows raised. "That thing’s practically an antique."

I nodded slowly, the gears in my mind turning. "Keep reading."

As Daniel continued reciting the recipe, I reached out and picked up the phone. The moment my hand touched it, the ringing stopped.

Instead, a video began playing.

It showed the train’s security footage. In the frame, two people ran through the train, heading toward a seat.

The footage was grainy, so I couldn’t make out their faces at first. But then, I realized—they were us.

In the video, the two figures picked up the phone that had been left on the seat.

"A passenger’s forgotten phone?" my voice asked.

"That thing’s eighty years old," Daniel’s voice replied.

"Keep reading," I heard myself say.

It was a perfect loop.

The Nina in the video picked up the phone, just like I had. And then the video replayed itself again. The same scene. Over and over.

Another loop.

I felt the chill sink in. We were stuck in this endless cycle. How could we even tell if we were the real us or just the video’s next iteration?

My spine tingled. This was contamination—stronger than what we’d faced before.

The logic of this zone was relentless repetition. Its whole purpose was to drive us mad, slowly but surely.

If I kept watching, I’d lose myself to it.

"Nina?" Daniel called out. He hadn’t seen the video, but he could tell something was wrong.

"Don’t look," I snapped. My mental value was higher than his. If Daniel saw this, he might completely break down.

"This is some serious mental contamination," I muttered as I tried to pause the video. But the phone wouldn’t stop. The loop continued, over and over.

I pocketed the phone, my hand shaking slightly. The contamination was starting to affect me.

System: *Mental value decreased by 1%.*

Ignoring the System’s warning, I moved toward the front of the train. "I’m turning in lost property to the conductor," I said to Daniel, my voice tight. "That’s just basic protocol."

Daniel’s eyes widened in disbelief. "Now? Really?"

I didn’t respond. In a contamination zone like this, the only way to fight back was to cling to normalcy. Act like everything was fine.

This was a normal train. I found a lost phone. I had to turn it in to the conductor.

This was normal. This was normal.

I kept repeating it to myself, trying to steady my mind.

Daniel followed close behind me as I approached the conductor’s cabin. Inside, someone was sitting in the driver’s seat, their back turned toward us.

The conductor appeared to be calmly driving the train, everything looking perfectly normal.

It couldn't be.

Nothing on this train was normal.

I took a deep breath and knocked on the glass door. "Excuse me. I found a phone. I’d like to turn it in."

No response.

I knocked again, louder this time. "Hello? I’m turning in lost property."

Finally, the conductor moved.

But instead of turning around, he took off his hat and raised his hands to his head. Slowly, his two hands parted his hair… revealing another back of a head beneath it.

He did it again, parting the second head to reveal yet another.

Clang—clang—

I suppressed a wave of nausea as the conductor continued peeling back heads like a grotesque Russian nesting doll, never showing his face.

Clang—clang—

Clang—

The noise had been echoing since I’d boarded the train.

The conductor’s door hadn’t been shut properly, and it rattled with the movement of the train.

I was about to reach for the handle when I froze.

Every muscle in my body went rigid.

"Nina?" Daniel asked, confused by my sudden reaction. "What’s wrong?"

Without looking, I shot a hand out, stopping him from moving any closer.

My back was to the conductor’s window, but I could see it in my peripheral vision.

A fish-headed creature's face was pressed up against the glass.

And it was smiling.

I had been wrong.

The contamination source wasn’t inside the train.

It had been clinging to the outside the whole time.