It's nighttime, and I'm on the toilet with my phone. I fire up Battleborn Arena, ready to grind a few ranked matches.

But an unknown number flashes on-screen and cuts me off. Annoyed, I decline the call, and a WhatsApp message pops up immediately.

"Run! Edgar just snapped. He's going to kill us all!"

My hands tremble.

Edgar Maguire… Isn't he already dead?

My teammates hit me with a string of question marks when my hero stood idle and failed to hold the base. Frustrated, I quit the game and opened WhatsApp.

The message was from Jacob Zeller, who lived downstairs from me. He was my roommate in college.

There were four of us sharing a dorm, and we were pretty tight. While we were interning, we decided to job hunt together and moved into a cheaper apartment to lower our rent.

Once everyone had a job, our hours were all over the place, so we each got an apartment to keep from getting in each other's way. We still grab a meal together from time to time.

Among the four of us, the oldest, Edgar Maguire, was unassuming and kind. He always looked out for us, and we treated him like an older brother.

He came from a village and was an orphan that the whole community helped raise. He studied hard, and whenever he had time, he took on part-time jobs to save up for tuition and living expenses.

When we were interning, he was the first to land an offer. But the good times didn't last. Three days ago, Edgar was murdered in his apartment. The killer still hasn't been found.

When I saw Jacob's message, a chill ran down my spine. That last call was him, too, so I called him right back.

I kept my voice low, the irritation edging through. "Jacob, what the heck are you talking about? Did you forget Edgar already passed away?"

His voice came over the line, shaky. "I-it's true. Did you check the apartment residents' group chat? The message was from Edgar!"

I hesitated for a beat and told him we'd follow up on WhatsApp, then pulled up the group chat. Out of habit, my phone was on silent, and the group chat was muted. After Jacob's reminder, I saw the message Edgar had sent.

303: "Everyone in this building is gonna die tonight!"

603: "What the hell is happening downstairs?"

304: "Wait, wasn't the guy in 303 already… dead?"

401: "Seriously, who's using his phone to pull a prank? This isn't funny."

Apartment 303 was Edgar's unit, and the message was coming from his WhatsApp account. The other residents were buzzing about it, but no one seemed to take that line seriously.

The building was six stories tall, with four units per floor, and it wasn't fully occupied. I shot Jacob a text. "Who took Edgar's phone after he died?"

He texted back, "No idea. It was never found."

I pursed my lips and replied, "Could the person who killed Edgar still be in this building?"

Jacob didn't text back for ages. Maybe that idea rattled him, too. Just then, someone knocked on the door.

"Police. Anyone home?"

I was on the toilet, my legs already tingling, my mind all over the place.

It hadn't even been 20 minutes since Edgar's text. The police couldn't be here already, could they? Besides, everyone in the building figured it was a prank. Who would've called the police?

I didn't dare make a sound. A fear I couldn't pinpoint crept through me.

Whoever was outside fell silent. My bathroom's right by the front door. I wiped as quietly as I could, pulled up my pants, and shuffled to the door.

I looked through the peephole and saw nothing but pitch-black. That made no sense. The hallway light was always on. It cast a dim yellow glow, but it was never completely dark.

Unless someone outside was peering back through the peephole.

The idea popped into my head, and I went stiff. I didn't even dare breathe.

"Nobody's home?"

I heard the guy outside mutter it through the door. I couldn't help feeling relieved. I'd gone straight for the bathroom when I got back, so the lights were still off.

He must've decided I wasn't home. He eased back from the peephole and looked down, tapping at his phone. He was a young man in a police uniform, fully kitted out.

After sending the message on his phone, he turned, headed across the hall, and knocked on the door opposite mine.

Was I overthinking this? Still, something felt off, and I couldn't say why.

I lived in apartment 601. Across the hall in apartment 603 was the guy who'd just texted in the group chat. He lived alone.

The two of us were the only ones living on this floor. He had a short fuse and often complained that people in the building were too noisy, which made him rather annoying.

Through the peephole, I saw the guy in 603 open his door. The officer was at the threshold, speaking to him. After a moment, the guy in 603 stepped back and let the officer inside.

I scrolled through my messages and finally realized what was wrong. By law, responding officers are supposed to arrive in pairs. So why had I seen only one a moment ago? Could someone have been impersonating an officer to gain unauthorized entry into the building?

I was frantic. Was the guy in 603 in danger?

Thunder rumbled faintly outside. Moments later, raindrops began hammering the window, making the panes rattle and ping.

I called the local police station and explained the situation, but the dispatcher said that officers were indeed patrolling our area. Since the killer still hadn't been caught, the department made the area a high priority.

I shot Jacob a text. "Did the police just come by your place?"

He texted back right away. "Yeah... I called the police after I saw the message. They were here a moment ago… They're searching the whole building now."

I let out a breath of relief, so he was the one who called the police. I finally relaxed and even laughed at myself for being paranoid.

Still, it had already been 20 minutes since the police went into apartment 603. The place wasn't that big. Did it really take that long to search one unit?

I shot Jacob another text. "How long were they at your place just now?"

He replied, "About… ten minutes."

I kept counting the minutes, eyes on the thread. And then it hit me. No, this wasn't Jacob.

I swiped up through my thread with Jacob. He never used ellipses, yet the last two messages did. If it wasn't Jacob texting, who was?

Across the hall, the door to apartment 603 opened. The officer stepped out, turned to the resident, and said, "Thank you for your cooperation."

Then, he left by elevator. The guy in 603 was fine. Maybe I was being paranoid again.

Outside was dead quiet when my stomach growled. That was when I realized I hadn't had a sip or a bite since I got home from work.

I flipped on the light and threw some mac and cheese in the microwave. While it hummed, I shot a text to Tom Bancroft.

He used to be our roommate—mine, Jacob's, and Edgar's. Tom was the quiet type. He didn't say much.

I asked Tom to check on Jacob next door. There might have been a killer outside, so it was better not to go out until things were clearer.

Tom's and Jacob's balconies were connected, which meant they could call to each other from there.

Tom replied with an "okay".

A little later, Jacob texted, "I was in the shower, so I could only reply with voice-to-text."

Ah, so that was it. I ribbed him a bit and felt much lighter. I guessed that what happened with Edgar rattled me more than I realized. I'd worked myself into a jumpy, paranoid state.

Even so, the question about the police still nagged at me. Why had I only seen one officer?

I thought it over and still couldn't shake it, so I took out my phone and texted the building manager, Gavin Blanchard.

"Gavin, did any police come by the building today?"

Gavin was new and pretty young. He lived in a little room by the front entrance on the first floor, where he could see everyone coming and going. If somebody walked in wearing a police uniform, there was no way he'd miss it.

He was obviously still up and texted back right away. "Yes. They still haven't caught the killer, so they come by sometimes to do a sweep."

"How many officers visited today?" I asked.

"Just one. I even went with him to a few units on the lower floors. By the way, did you and your friend head out to eat? The officer said there wasn't anyone home at either of your apartments."

Gavin sent another message. "Once you're back, I'll bring the officer up to your place. Or he won't be able to report back if he doesn't get to search your unit."

I was about to type when I stopped cold. That officer had literally just gone downstairs. How did Gavin find out so quickly?

And there was another line in Gavin's message that nagged at me. We were both young, and we'd chatted a few times. The only person he'd ever seen me go out to eat with was Jacob.

So by "friend," he had to mean Jacob.

Wasn't Jacob at home? Didn't Tom just confirm that he was? So who was lying here?

I fired off a text to Tom, but he never replied. So, I texted Gavin back, "We have a team-building event at work tonight, so I'm staying out and won't be back."

I trusted no one but myself. Gavin didn't reply either.

I hurried through my mac and cheese and locked the door. I had no idea what was happening outside. All I could do was close up the doors and windows and keep everyone else out.

I ran through the building in my head. On the sixth floor, it was just me and the guy in 603 across the hall. The fifth floor had Jacob, Tom, and a college student in 504. The fourth floor had only 401, which was occupied by someone I'd never met.

Since Edgar's death, the third floor had been reduced to just one occupant—304, which was the only tenant bold enough to continue living there.

The second floor was full, but I didn't really know anyone. I'd only seen a man and a woman in the elevator. They looked like a married couple. On the first floor, there was an elderly man who had trouble getting around, and then there was Gavin.

Aside from my former roommates, the only person in this building whose number I had was the guy in 603 across the hall.

I was still worried about Jacob, so I texted Tom again, but he didn't reply either.

I ended up opening the group chat and adding the guy in 504. We were all young night owls, but after waiting a good while, he still didn't respond.

By midnight, I finally lay down. Maybe he was beat and turned in early.

The rain outside showed no sign of easing. It drummed on the window and kept me from sleeping. I sat up to find my earplugs when my phone lit up. It was a text from the guy in 603.

"Don't you think tonight feels a little off?"

I came fully alert. Thank goodness. I wasn't alone!

I didn't talk much with the guy in 603. For once, a text from him actually made me glad.

"Did you feel it, too? How was it when the officer stopped by just now?" I asked.

"So you're home, yeah? I told the officer I heard the elevator, but he said there was no one home across the hall. He just popped in and had a quick look, then got weird about it and insisted on checking my knives up close. He only left after that."

I told him I was glad nothing had happened, and he texted again almost immediately.

"It's way too quiet tonight. Usually, the guy downstairs is gaming at this hour, but tonight there's nothing."

I was taken aback. Even with the rain pouring down, he noticed the silence below.

Still, he was right. That college student downstairs often blasted his game audio and talked with his teammates on voice chat. Even I could hear it.

But tonight, it was just the rain. I texted, "Maybe he didn't game tonight. He could've turned in early."

The guy in 603 replied, "Could be, but it's Friday. This is when he'd usually pull an all-nighter."

I had nothing to say. The student in 504 still hadn't replied to my message, and the silence just made the fear worse.

I texted, "We don't really know what's going on yet. Let's talk tomorrow."

"Yeah."

I put my phone down, but sleep wouldn't come. As my nerves built, I needed to pee, so I got up and went toward the bathroom.

But I stopped before I reached it. Given how dark the room was, there should have been a sliver of light under the door. Instead, it was completely dark.

Someone was lying on the floor outside my door.