I felt my muscles tense as the scratching grew louder again. It was coming directly from the hallway, and my hand gripped the weapon tighter. Seulgi clung to my arm, her eyes wide with fear. "It's him," she whispered, barely audible.

Slowly, I stepped forward, flashlight raised. The noise intensified, but something about it was strange. Not threatening—more like... scratching, scraping. As if from something smaller.

Then, from the shadows, a small, skinny-looking cat emerged. It slunk out of the hallway, its large, yellow-green eyes reflecting the light from my flashlight. Its fur was scruffy, and it meowed softly as it approached us.

I took a deep breath, the tension easing a bit, and I lowered the weapon. "Just a cat," I murmured, almost to myself, as I relaxed my shoulders. The threat I had anticipated dissolved into relief. But at that moment, I heard Seulgi gasp behind me.

I immediately turned to her. Her eyes were tearing up, and she was gasping for air. "Seulgi! What's wrong?" Panic flared in me as I saw her cheeks swell red and she frantically rubbed her nose.

"C-Cat..." she managed to say before she started sneezing. Suddenly, it all made sense—Seulgi had a cat allergy.

"Damn," I muttered under my breath. "Okay, stay calm, breathe deeply. We need to get out of here."

The cat stayed innocently nearby, purring as it got closer to Seulgi. I could see her condition worsening—her breaths grew shallower, and her eyes began to water as if she were suffocating. I quickly pulled her away from the cat, but the animal followed us curiously, unaware of the chaos it was causing.

"Wait here," I ordered, taking a step toward the cat to gently push it away. The creature didn't resist, simply turning and disappearing into another room. I hurried to get Seulgi to the door. "We need some fresh air."

I flung the door wide open, and a cool breeze rushed in. Seulgi was still coughing and gasping for breath as she staggered outside. The fresh air would hopefully help her calm down. "Stay here," I said as she leaned against the wall, desperately trying to breathe normally again. "I'll get you some water."

I ran to the kitchen and quickly searched the cabinets. My thoughts raced. How long had that cat been here? Did it even belong to anyone? The apartment had been empty before, with no sign of a pet. Had it just wandered in?

I finally found a bottle of water, tore off the cap, and rushed back to Seulgi. Outside, she was still pale, but she managed to take a few deep breaths. "Here," I said, handing her the bottle. She took a large gulp and gradually started to calm down.

"Are you feeling better?" I knelt beside her and held her trembling hand. Seulgi nodded weakly, wiping her eyes with her sleeve. "It... was just a cat," she said softly, her voice shaky.

"Yeah, but that's enough, isn't it?" I tried to smile, but inside, I was worried. The cat was definitely not the biggest enemy here, but the fact that it had brought Seulgi to this state complicated everything. "I'm sorry I didn't think about it."

Seulgi shook her head. "It's not your fault. I didn't expect it."

I helped her to her feet, and we slowly walked a few steps away from the apartment to get more fresh air. My gaze drifted back to the building, and I wondered if the cat was just a coincidence. After all, it was small, innocent—but something about its presence felt strange, almost like a distraction.

Seulgi sat down on the steps and briefly closed her eyes as she took deep breaths. "What now?"

I looked around, listening to the quiet night. "We should search the apartment. If the cat was in there, it might have come through an open window... or someone let it in."

I knew I had to stay vigilant. The feeling that something bigger was waiting for us wouldn't go away. "Stay here, I'll go check," I finally said before heading back to the apartment.

With cautious steps, I re-entered the apartment. The uneasy feeling in my stomach grew stronger with every step. The cat was gone, but my instincts told me there was more to discover. The slight creak of the floorboards under my feet and the darkness heightened the tension within me. I drew my weapon from its holster—just in case.

The living room was still and eerie. The cat had hidden somewhere, maybe it had slipped in through a window, but there were no clear signs. I went to the terrace door, pulled the curtain aside, and checked the lock—securely fastened. The windows in the bedroom and kitchen were also firmly closed. So how had the cat gotten in?

I inspected every corner of the apartment, searching for anything unusual that might explain why the cat was even here. But nothing. No sign of a break-in, no open windows, no suspicious items.

Then, in a moment of silence, I heard it. A faint humming—like from an electronic device. It was coming from one of the cabinets in the kitchen. My heart raced as I carefully opened the cabinet. A small, inconspicuous device lay there, which at first glance looked like an ordinary router. But it wasn't a router. The small blinking LED on it told me it was some kind of surveillance device.

Damn. Someone had been monitoring this apartment.

That meant they knew exactly when Seulgi was here. They might have even watched us come in. I carefully picked up the device and examined it more closely. No obvious indication of who it belonged to, but the fact that it was hidden here left no doubt—someone had planned to monitor Seulgi.

I had to get back to her.