The letter arrived at dawn, tucked inside a plain white envelope with no return address. Captain Kim Soo-Young barely had time to process it as she sat on the edge of her cot, still gripping the letter. The world outside was still cloaked in darkness, save for the harsh, artificial glow of floodlights illuminating the military base.
The words on the page blurred as she read them for the third time. The morning drill horn blared again through the military base. She hesitated, gripping the thin paper between her fingers, her heart pounding harder than it had on any battlefield
The soft rustle of paper was the only sound in Captain Kim Soo-Young's ear's.
It was from Ji-Hyun.
Her daughter's handwriting was neat but slightly rushed, as if she had scribbled it down in stolen moments.
Mom,
I know you're busy, but I need you.
Dad left me with that woman again. She locks me in my room when he's not here. I only get food when she remembers. Last night, she hit me.
I don't know what I did wrong.
I tried calling, but he took my phone. Please… just come home.
Soo-Young's fingers curled around the letter, the thin paper crumpling slightly under her grip. Her heart pounded against her ribs, fury burning beneath her skin like molten steel.
Her ex-husband had done many unforgivable things—cheating, lying, abandoning his family—but this? This was something else entirely.
Choi Min-Seo.
The woman!. The mistress her husband had hidden for years. The one he swore he ended things with when Soo-Young found out. She had been a shadow looming over Soo-Young's marriage for years. Even after their divorce, her ex-husband swore that Ji-Hyun would be safe, that Min-Seo would never be involved in their daughter's life.
Lies.
But now, it was clear—he hadn't just betrayed her. He had abandoned their daughter to a monster.
Ji-Hyun was only fifteen. She was still just a kid. And Soo-Young… she had been so caught up in her duty, in serving a country that barely saw her, that she had left Ji-Hyun to suffer alone.
No more.
She crushed the letter in her fist, a slow, burning rage inside her. Soo-Young stood abruptly, the cot creaking under her sudden movement. Her mind was already racing ahead, calculating her next move. The military had her locked in—quite literally. Leaving the base without permission was desertion. If she was caught, she could be court-martialed. Desertion. That's what they'd call it. The military didn't take kindly to soldiers abandoning their posts, especially ones with Soo-Young's rank and experience.
But she didn't care.
But Ji-Hyun needed her. And no regulation, no threat of punishment, was going to stop her from reaching her daughter.
*****
Soo-Young moved swiftly, her years of military training keeping her steps silent as she maneuvered through the base. The night was still, save for the distant hum of generators, and the occasional bark of orders from the security perimeter.
She had packed light—civilian clothes, some cash, and a few stolen rations. Her military ID could still get her through certain checkpoints, but it would also be the first thing flagged once they realized she was gone. The hardest part was leaving behind her uniform. It had been a part of her identity for so long, but tonight, it was nothing but a hindrance.
Reaching the outer perimeter, she crouched behind a stack of supply crates, scanning the area. The watchtower's searchlight swept across the yard in slow, rhythmic arcs. Timing her movements with precision, she darted across the open space, pressing herself against the cold metal of a supply truck.
A voice cut through the silence.
"Captain Kim."
She froze.
Slowly, she turned to find Sergeant Park standing a few feet away, arms crossed over his chest. His sharp eyes flickered to her bag, then back to her face.
"You running?" he asked, his tone unreadable.
Soo-Young clenched her jaw. Lying was pointless. "I have to get to my daughter."
Park was silent for a moment, then exhaled heavily. "You know if they catch you—"
"I don't care."
Another pause. Then, Park shook his head with a faint, exasperated sigh.
"Go," he said, nodding toward the perimeter gate. "Before someone else sees you."
Soo-Young blinked. "You're letting me—"
"Just go," he repeated. "Before I change my mind."
She hesitated for only a second longer before slipping past him, disappearing into the shadows.
****
By the time she reached Seoul, the city was a different beast altogether. the streets were worse than she remembered. Protests against the government had turned violent, the protests lined the streets, fueled by growing distrust in the government. The News channels spoke in hushed tones about something happening in the southern districts. It was filled with reports of the sudden violent outbreaks of the same southern districts, but no one seemed to have a clear answer as to why.
But Soo-Young had no time for any of
She barely paid attention to the protesters. She had one goal: get to Ji-Hyun.
She made her way straight to her husband's apartment, breaking in when no one answered. Breaking into her ex-husband's apartment was easy. The lock was cheap, the security nonexistent. She expected to find Ji-Hyun asleep, maybe hiding in her room. Instead, the apartment was empty.
The place was empty. The bed, unmade. Expensive perfume still lingered in the air.
Ji-Hyun was gone.
Soo-Young's breath came sharp and fast as she searched the rooms. Her mind raced through possibilities—was she at school? Did her husband take her somewhere?
Her stomach twisted as she going to search the rooms. The place was a mess—unwashed dishes, discarded beer cans, and the lingering scent of expensive perfume.
Then, she saw it.
A half-empty bottle of water on the counter. Tiny reddish-black specks clung to the rim.
A chill ran down her spine.
Something was very, very wrong.
Then, the screaming started outside.
And the world fell apart.
---
The Last Train to Busan
Soo-Young had no time to process the chaos unfolding in the city. By the time she tracked Ji-Hyun's phone signal, she was already moving toward Seoul Station.
The streets were filled with sirens, people running, military blockades forming at key intersections. Whatever was happening, the government was scrambling to contain it.
She didn't wait to find out.
Her daughter was her priority.
When she finally reached the station, she spotted Ji-Hyun near the ticket counters, clutching her backpack like a lifeline.
"Mom!"
Relief flooded through Soo-Young as she pulled her daughter into a tight embrace. "Are you hurt? Did she—"
"I'm okay," Ji-Hyun whispered. "I just… I just wanted to get away."
Soo-Young exhaled sharply. "We're leaving."
They boarded the train to Busan just as the city sirens blared louder, echoing like a warning through the station.
---
The First Infection
The train was nearly full, packed with travelers desperate to leave Seoul from what they don't know yet. Among them were a handful of workers, a frail-looking scientist clutching a briefcase, and businessmen pretending not to notice the panic outside.
As the train pulled away from the station, Soo-Young allowed herself a rare moment of relief.
Then, a loud cough broke the silence.
A man two rows ahead of them bend over, sweat beading on his forehead. He reached for his water bottle, taking a slow sip.
Seconds later, his body jerked violently. His veins darkened, spreading like black ink beneath his skin. His breathing turned ragged.
The train car developed into screams of fright as the infected man struggle for control against his seat, his fingers clawing at his own throat. His body shakes violently, muscles seizing beneath his skin as blackened veins shoots across his face like cracks in shattered clay pot. His pupils shrank to pinpricks before his eyes rolled back entirely, leaving only the milky whites staring blankly at the ceiling.
Then, his jaw turned sideways slowly.
A sickening cripy sound filled the air as his teeth gnashed together, grinding against themselves like a starving animal desperate for flesh. His fingers, once human, bent in unnatural angles, nails peeling away as sharpened bone pushed through the bleeding gaps. The sound of tearing skin and wet, feeble muscle filled the cabin, mingling with the panicked cries of passengers scrambling to get away.
A middle aged woman beside him whimpered weakly, her hands clasped over her mouth. At her sobs, the infected man's head snapped toward her so fast his neck cracked, the noise like dry twigs snapping underfoot in winter season. His lips curled back, revealing jagged, bloodied teeth. A deep, rattling growl rose from his chest before he lunged swiftly at her.
The woman didn't even have time to scream. His jaw clamped down on her shoulder with a sickening move. Flesh ripped off like wet paper, blood shooting out in thick, pulsing streams onto the train floor. The woman shrieked in agony, flailing desperately as the thing that was once a man ripped away a chunk of her skin.
Soo-Young was on her feet in an instant, shielding Ji-Hyun.
Then, watched how the transformation begin a new with the woman.
Her body shakes violently as the infection took hold on her. The blood that gushed from her wound darkened, turning thick like tar. Her veins blackened, pulsating beneath her skin like writhing worms. She clawed at her own face as if trying to tear away whatever was happening to her—but it was too late.
She arched backward in a flip-flop style seizure, her mouth stretching wider than humanly possible. Her teeth cracked, and elongated into jagged, monstrous fangs. Her fingers split open at the tips, nails falling away to reveal sharpened bone. Then, she let out a loud guttural, inhuman screech before turning on the passengers nearest to her.
Panic spread through the train car like wildfire.
People pushed, shoved, trampled each other to get away. The infected moved with unnatural speed, their bodies jerking in rapid, aggressive motions, like puppets controlled by a shaking hand. Their heads twitched violently as they sniffed the air, searching for their next victim.
And they found them.
One after another, passengers were pulled down, their screams swallowed by the sounds of tearing flesh, and violent death.
Soo-Young shoved Ji-Hyun behind her, heart hammering in her chest.
"We need to move. Now."