Cheong-san looked away at the last second, unable to watch as his best friend fell towards the ground. He let out a sob, feeling Y/N clutching onto his back, trying to pull him away from the window. A sharp cry had his eyes snapping open in surprise, mouth going slack when he realized it was Na-yeon's scream. The pair had managed to fall into a bush outside the building, which had broken their fall, and appeared relatively unharmed from the way Na-yeon was thrashing about. She was quick to push herself to her feet, jumping out of the bushes as she continued crying. She stumbled over her feet, falling to the ground as a group of zombies advanced on her, blood dripping from their mouths.

"Shit..." Cheong-san exclaimed, noticing how Gyeong-su was only just starting to wake up, none the wiser to the danger that was close by.

"What do we do--" Y/N began, when a hand suddenly pushed her out of the way.

Her jaw dropped open as Ms Park crawled up onto the windowsill, giving the group one last sad smile before she jumped down below. The students watched in horror as she landed in a heap on the grass below, the loud thud distracting the zombies which were inches away from Na-yeon. From the awkward angle her leg was underneath her, it was clear she had broken it.

"Run!" Ms Park yelled, ushering Na-yeon away, as one of the zombies lunged at her.

The crying girl did as she was told, pushing herself to her feet and sprinting away, her hand clasped over her mouth. Y/N grimaced as more zombies advanced on Ms Park, biting her from every angle, dragging her to the ground. Her eyes quickly flickered over to Gyeong-su, who was only just waking up, clutching at his head.

"Gyeong-su!" Y/N cried, as the group rushed forward to crowd around the window.

The students all began shouting his name, as Gyeong-su's eyes flickered open, a horrified gasp leaving his lips as he saw the zombies just metres away from him. He looked up at them, a terrified expression over his features. They could no longer see Ms Park, as she had been completely covered by the zombies that had surrounded her. It was far too late to save her.

"Go, Gyeong-su!" Cheong-san pleaded, as Gyeong-su cautiously crawled out of the bushes, his bottom lip wobbling.

"I'll find you. I swear, I'll find you!" Cheong-san called out, as Gyeong-su gave him a sad nod, before he took off running in the opposite direction Na-yeon had gone.

Cheong-san's hands clutched onto the windowsill as he watched his best friend disappear from view, wanting nothing more than to chase after him. How far could he get on his own? Cheong-san could think of nothing worse than being on your own in such a situation.

"Cheong-san--" Y/N began, reaching out to touch his arm, as he roughly brushed her away.

He turned his back to her, before he suddenly struck his fist against a nearby metal cupboard, making Y/N flinch. She grimaced as he continued hitting the cupboard, his knuckles becoming bloody as he let out a sob. Still shaking, he dropped his fists to his side, resting his forehead against the cupboard, trying to control his erratic breathing.

"She's gone. Ms Park is gone" Dae-su cried, bringing his hands to cover his face as tears dropped down his cheeks.

With her own eyes filling with tears, Y/N was quick to approach the older boy, wrapping her arms around his shoulders, bringing him into a hug. Dae-su quickly returned the embrace, dropping his head onto her shoulder, his tears wetting her shirt. She looked up to see Su-hyeok placing his hand on Dae-su's shoulder, squeezing comfortingly.

"Get in here, Bare-su" Dae-su insisted, nudging the other boy with his elbow.

With his lips twitching into a smile, Su-hyeok did as he was told and draped his arms around the pair, bringing them close to his chest. The students continued holding each other for a while longer, none of them wanting to let go, terrified of losing anyone else.

-----------------------

An hour later, the group had come across their next problem. Their bladders. Su-hyeok's in particular. The students had busied themselves with setting up a makeshift toliet in the recording studio, while Dae-su insisted that they could still lean out of the window to take a shit.

"You agree with me, right Cheong-san?" Dae-su inquired, turning to the boy who had spoken a word in the past hour.

"I've got this" Y/N murmured, walking over to the window that Cheong-san was still standing at.

"You did everything you could" Y/N insisted, watching her brother's forehead wrinkle.

"I should have followed him. He was my best friend and I just...let him go" Cheong-san muttered, as Y/N let out a sigh, not knowing what else she could say.

She noticed the way he was still clenching his fists, blood dripping down from his knuckles. Y/N was quick to tug off her tie, and grabbed Cheong-san's hand, surprising him. She broke the tie in half and used the fabric to wrap around his knuckles, worried what would happen if he had open wounds. She couldn't lose her brother. Not ever.

"You know it's supposed to be the other way round" Cheong-san pointed out.

"Huh?" She frowned.

"I'm your big brother. I'm supposed to be the one looking after you" Cheong-san exclaimed, as she gave him a small smile.

"Well, I'm better at it" Y/N shrugged, making Cheong-san snort.

"...Do you think mom and dad are okay?" Cheong-san couldn't help but ask, looking back out the window.

"I'm sure the city has been evacuated by now. They should be safe" Y/N replied.

"Should be" Cheong-san sighed, with a shake of his head.

"We need to stay alive, Cheong-san. For them. For each other, okay?" Y/N insisted, as her brother's eyes softened.

A loud moan caught the sibling's attention, as they turned towards the recording studio, wondering who had made the noise. Her eyes flickered around the classroom, noting only one person was missing.

"I guess Bare-su really needed to go" Dae-su chuckled, as Y/N's cheeks reddened.

The last thing she should have been thinking about was how hot her brother's friend sounded moaning. She was dealing with a zombie apocalypse, there was going to be no time for romance.

"Here, Y/N. You should drink something" Nam-ra announced, approaching her, handing out one of the few water bottles they had remaining.

"We should ration the water, right? We don't know how long we'll be stuck here" Y/N suggested, as Nam-ra shook her head.

"You didn't drink enough earlier. I don't want...I mean, it's important you don't get sick" Nam-ra explained, stuttering over her words a little.

"What would I do without you, Nam-ra?" Y/N replied, in a teasing tone, as she took the water, earning a bashful smile in response.

She didn't see the way Cheong-san's eyes flickered between the two, before landing on Nam-ra and crossing his arms. He wasn't sure if he liked the content look she was giving his sister.

---------------------------

The sky outside was dark by the time the students decided to settle down for the night. There was no point in trying to escape from the school at night. And they knew they needed enough sleep or they wouldn't be able to fight the zombies outside. Most of them fell asleep quickly, too exhausted to stay awake any longer. Y/N stayed by the window, leaning against the glass as she wondered where Gyeong-su was. If anything happened to him, she wasn't sure her brother would cope...

"You should sleep" Su-hyeok stated, coming to stand beside her.

"Someone needs to keep watch" Y/N shrugged.

"I'll take first watch then" Su-hyeok insisted, as she quirked an eyebrow.

"...I guess I could rest my eyes for a few minutes" Y/N mumbled, surprised when Su-hyeok reached out to take her hand, his palm feeling warm against hers.

He gave a small tug and led her to the metal cabinets, where he had already removed his shoes and pulled her down to sit next to him. As her legs touched the cold floor beneath them, Y/N couldn't help but shiver, which caught Su-hyeok's eye. Before she could stop him, he was shrugging off his blazer and placing it over her like a blanket. She gave him a small smile, wiggling a little closer towards him until there legs touched.

"You know, when I woke up this morning, I didn't expect to be sleeping with Cheong-san's best friend" Y/N exclaimed, with a teasing grin, making him huff out a laugh.

"I imagine the zombies were a bit of a surprise too" Su-hyeok pointed out.

"...I was wondering, if we survive this, maybe we could, uh...go visit Hyeon-ju after school some time?" Su-hyeok inquired, with a shy smile.

"And what would we do in Hyeon-ju?" Y/N replied.

"I can think of a few things" Su-hyeok grinned, as Y/N felt her cheeks redden a little.

"...Okay. It's a date" She grinned.

"Really?" Su-hyeok exclaimed, his face lighting up with excitement.

"Well, you did save my life today. It's the least I can do, right?" Y/N teased, as Su-hyeok shook his head fondly.

They both looked away with a smile, leaning back further against the cabinets behind them to get more comfortable. Su-hyeok let out a quick yawn, his eyes darting down to Y/N, as he stretched his arm out behind her shoulder, bringing her a little closer to him. His heart quickened when she laid her head against his own shoulder, the heat from her body quickly warming him. Soon, both their eyes closed and they fell into a surprisingly comfortable sleep, a strange sense of safety enclosing around them.

---------------------

The sun was shining against Y/N's face as her eyes fluttered open, feeling the soft beat of Su-hyeok's heart under her cheek. She looked down to see his arm had drifted down during the night, and was now resting against her hip, causing her lips to twitch into a smile. She slowly pulled herself away from him, stretching her aching neck, and moving his blazer so it was covering his lap instead. His hair had fallen into his eyes, and she found an odd urge to touch his face. He really was so fucking attractive.

A second later, she felt eyes on her and twisted around to see Nam-ra all but glaring at them. She quickly pulled her gaze away when she realised she had been seen, scrunching her eyes shut, pretending to have been sleeping the whole time. With a grin, Y/N grabbed a nearby scrap of paper and rolled it in her hands. She threw it towards an unsuspecting Nam-ra, hitting the older girl in the chest, her eyes snapping back open. With a mischievous look in her eye, Nam-ra was quick to grab the discarded paper and threw it back to Y/N, who ducked just in time. The two girls burst out laughing after that, as Y/N thought about how uncharacteristically carefree Nam-ra seemed.

"Did you sleep well?" Y/N whispered, trying not to wake up the others, as Nam-ra shook her head.

"I was trying to figure out our next move" Nam-ra informed her, as Y/N pushed herself to her feet.

"And what did you come up with?" Y/N asked, walking over to her.

"No one is coming to rescue us" Nam-ra told her, as Y/N jumped up to sit on the table Nam-ra was resting her arms on.

"We don't know that" Y/N suggested, as Nam-ra pursed her lips.

"They won't even realise we're...um, that we're...alive..." Nam-ra stuttered over her words, cheeks reddening with every passing second.

Y/N frowned at this reaction, eyes flickering down when she noticed where Nam-ra's gaze lay. A blush rose on her own face when she saw how her skirt had risen up, giving the other girl a good view of her black panties. She quickly crossed her legs, pulling her skirt down, with an awkward laugh.

"Sorry" Y/N mumbled, as Nam-ra shook her head.

"I-it's fine, I don't mind...I mean, I wasn't looking...I did, but I wasn't trying to..." Nam-ra trailed off, cringing at her own words.

"I don't think I've ever heard you talk so much" Y/N giggled, as Nam-ra gave a shy shrug.

"...Maybe I'll have to flash my panties at you more often" Y/N teased, as the other girl's eyes widened, before they began laughing again.

A loud cough from the other side of the room had Y/N whipping around to see Cheong-san wide awake, his arms crossed and eyes narrowed. She grimaced when she realised what he must have heard, and immediately jumped off the table, running a hand through her hair.

"No one came?" Cheong-san asked, as Y/N shook her head.

"Nam-ra pointed out they probably don't even realise we're here" Y/N explained, as the others started to wake up.

"Can't we post something online?" Cheong-san suggested.

"I think we might have problem with that...no WI-FI" Joon-Yeong informed them, having tried to turn on the computer in the room.

"Fucking great" Y/N complained.

"We need a phone. Then we could ring for help" On-jo murmured, stretching her arms above her head.

"But we don't have one" Su-hyeok stated, with a yawn.

"The teacher's office. That's where everyone's phones are" Cheong-san realised.

"But we can't get there. It's on the other end of the building, we'll never get past all the zombies" Y/N pointed out.

"...Not if we go out through the window" Cheong-san grinned, rushing over to the windowsill.

"It's too dangerous! What if you fall?" Y/N cried, rushing to her brother's side.

"Ah, don't be so dramatic, Y/N. I'll be fine" Cheong-san insisted, leaning out of the window, as his sister threw her arms up in the air, clearly annoyed.

"Cheong-san, listen to your sister. Stop being so stubborn" On-jo announced, racing over to the pair.

"The teacher's office is only four rooms across. I can make it" Cheong-san told her, as he jumped up onto the window ledge.

"Don't go" On-jo blurted out, before she could stop herself.

"I'll come back if anything goes wrong. Don't worry" Cheong-san replied, making On-jo frown.

"I'm not worried. Just angry" On-jo huffed, as Cheong-san pursed his lips.

"Sure. Why would you worry about me?" Cheong-san sneered, before standing up on the ledge and beginning his journey.

"Cheong-san, don't!" Y/N cried, her voice full of panic.

"Damn it" Su-hyeok sighed, pulling his blazer on and rushing over to the window.

"I'll look after him" Su-hyeok exclaimed, jumping up onto the ledge and following closely behind her brother.

"...Fuck it" Y/N muttered, before crawling onto the ledge herself.

"Shit, who's next?" Ji-Min huffed, as Y/N looked back into the classroom, her eyes meeting Nam-ra's, who jumped up from her seat, surprising the group.

"Be careful" Nam-ra insisted, earning a small smile in response.

"I'll be back" Y/N said, making sure it sounded like a promise before standing up and shuffling after the other two boys.

"Why do you keep following me?" She could hear Cheong-san ask, from a few metres away.

"Who else do you have?" Su-hyeok grinned.

"Me" Y/N announced, as they both turned to her in surprise, eyes wide.

"Y/N? What are you doing? You're scared of heights!" Cheong-san gaped.

"Well, I'm more scared of losing you, idiot" Y/N retorted, as her brother's lips twitched into a smile.

"Stay close, stupid" Cheong-san smirked, ushering for them to follow him, as he jumped over one of the pillars.

"He's lucky to have you" Su-hyeok murmured to her.

"...He's not the only person I came for" Y/N shrugged, as Su-hyeok gave her a fond look.

"Hurry up!" Cheong-san called back, as Y/N rolled her eyes, as they started to follow him.

They made it across one of the rooms with ease, but the next classroom was full of zombies, some of which were already looking out of the window. They hadn't been clever enough to open doors yesterday, so surely they couldn't open windows either? Still, it had the group stopping for a moment, debating their next move.

"What are you going to do?" Cheong-san questioned.

"If we're quiet they probably won't see us--" Su-hyeok began, but Cheong-san quickly cut him off.

"No, I don't mean that. I heard On-jo told you that she likes you...are you going to go out with her?" Cheong-san asked, as Y/N had to stop herself from face palming.

"Is that important right now?" Su-hyeok pointed out.

"I agree" Y/N muttered, eyes flickering to the high drop below them.

"I'm not asking because it's important. I'm just...curious. That's all" Cheong-san retorted, defensively.

"Why? Do you think I should?" Su-hyeok queired, in a teasing tone.

"Why would ask me that? Do whatever you want" Cheong-san shrugged, as Su-hyeok kicked his foot.

"What do you think?" Su-hyeok insisted.

"He wants you to say no so he can ask On-jo for himself" Y/N grinned, as Cheong-san shot her a death glare.

"At least I don't go around flashing people" Cheong-san scoffed, as Y/N stuck her tongue out at him.

"What do you mean?" Su-hyeok asked, eyes darting between the pair in confusion.

"She flashed Nam-ra" Cheong-san stated, with a smug look, before he crawled over the pillar and started shuffling past the next classroom.

"...You like Nam-ra?" Su-hyeok frowned, in a hurt tone.

"Do you like On-jo?" Y/N retorted.

"You didn't answer my question" Su-hyeok exclaimed.

"You didn't answer mine" Y/N murmured, as Su-hyeok went to open his mouth, when they heard Cheong-san hissing at them to hurry up.

They were able to get past the next three classrooms without much issue, finally reaching the teacher's office with one last obstacle. A rain gutter was in their way. Cheong-san and Su-hyeok were able to get past it pretty easily due to their longer arms, but Y/N lost her footing as she tried to jump across, letting out a cry, almost falling from the ledge if Su-hyeok hadn't reached out to grab her. His arms enclosed around her waist, pulling her body past the gutter and flush against his body. Y/N found herself clutching his chest before she knew what she was doing, letting out a sigh of relief.

"Thanks" She said, breathlessly.

"I'd never let you fall, Y/N" Su-hyeok told her, as she gave him a grateful smile.

Suddenly they heard a sharp female scream, making them all flinch as Cheong-san crouched down to look through the window. He grimaced as he saw a student being attacked in the corridor, more and more zombies grabbing onto her. He wanted to help, but he knew it was already too late.

"We should go now. While they're distracted" Y/N suggested, as Cheong-san nodded.

Painfully slow, Cheong-san opened the window to the office, scrunching his eyes shut as he heard the wood creak. Once the window was fully open, the three jumped into the classroom, staying on their hands and knees. They rushed to the other side of the classroom, luckily finding no zombies in their path. Cheong-san held a hand up when they heard a strange thumping sound past one of the desks. Cautiously, the group peeked past the desk, frowning when they saw a girl smashing all the phones. It was odd. She seemed human, but...angry? There was something in her eyes that made Y/N's heart beat quicker. She found herself wanting to run from the room.

"What the hell?" Su-hyeok whispered, as they watched her stand up.

The girl continued to smash the phones on the desk in front of her, missing her aim at one point and smashing one of her fingers instead, causing Y/N to gag. Su-hyeok quickly placed his hand over her mouth, silencing her from making any other sounds. The strange girl didn't even seem to notice she had mangled her finger, breaking more and more phones. A moment later, one of the phones flopped to the ground, practically in reaching distance. Before they could stop him, Cheong-san was crawling forward, wrapping his hand around the phone. He felt his heart stop when the smashing sound suddenly ceased, his eyes snapping up to meet the deranged student. She shook with anger for a second, before letting out a piercing scream.

"I'll kill you!" She screamed, rushing towards Cheong-san, throwing him onto his back.

Su-hyeok instantly grabbed her by the shoulders and threw her roughly into one of the filing cabinets, the crashing sound reverberating across the room. Y/N pulled her brother to his feet, all but dragging him towards the window, with Su-hyeok following close behind. Cheong-san went cold when he realised the phone he had grabbed was also smashed. He couldn't let this all be for nothing. Y/N gaped as he suddenly twisted around and ran forward, sliding underneath one of the desks to the pile of broken phones.

"Cheong-san!" Y/N shouted, as all the zombies in the room started stumbling towards them.

Grabbing a nearby phone that appeared to be intact, Cheong-san barely managed to duck in time as a zombie swiped at him. His hands wrapped around a nearby chair, using it to keep two other zombies at bay, but he knew he wouldn't be able to hold out for long. He turned to see a group of zombies descending on Y/N and Su-hyeok, cutting off his way back to the window.

"Go back! I'll find another way!" Cheong-san insisted, throwing the chair he was holding at the zombies and jumping over the desk.

"No! Cheong-san, don't!" Y/N cried, as she watched her brother kick out at another zombie before running out of the room.

They could hear more growling coming from down the corridor, as the creatures followed closely behind Cheong-san. Grabbing the knife from her pocket, Y/N lunged forward and stabbed the nearest zombie directly in the eye, throwing their slumped body against the two other zombies approaching them.

"I'm not leaving my brother" Y/N announced, as Su-hyeok quickly nodded, not having expected anything less.

Grabbing her hand, they jumped onto the nearest desk, jumping across to the next one to narrowly missing the zombies biting at their heels. With one more large jump, they managed to make it to the doorway unscathed. Stumbling out into the corridor, they could see no sign of Cheong-san but a few straggling zombies were still racing to their left. With no other plan, they sprinted forward, kicking out at two zombies who had their backs to them, throwing them to the floor. Rounding the next corner, the pair came to a sudden halt when they found more than a dozen zombies on the steps, all whipping around to face them. Without a second thought, Y/N was tugging Su-hyeok backwards and throwing herself against the nearby glass window, which smashed against their weight. The pair fell through the first floor window, but instead of hitting the ground, it was zombie that broke their fell. Y/N grimaced as the creature tried swiping at them, despite the way it's neck was bent to the side, probably broken. Su-hyeok pulled her to her feet, as they sprinted across the courtyard to a nearby open window. They spent the next few minutes racing around the corridor, and in and out of classrooms when they heard a familiar shout. It was Cheong-san.

Y/N instantly raced out into the corridor, eyes wide when she saw her brother sprinting away from her. Just as she was about to call after him, a hand suddenly grabbed her by the hair, wrenching her backwards. Y/N let out a cry as she was flung towards two zombies, who grabbed onto her arms, their mouths snapping at her neck. She desperately tried to push them away, but they were far stronger, managing to send her falling onto her back. She looked up, hoping Su-hyeok would be coming to her rescue, but he already had his hands full. He was fighting with another boy, sending a hard punch to his face. It was Gwi-nam. He must have been the one who grab her. Of course he was. Pulling one of her hands away from her attackers, she was able to get a better grip on her knife and sliced the nearest zombie's neck open, as it flopped to the floor. With an angry cry, she grabbed the other zombie by their hair and smashed their head against the wall, again and again until the creature stopped moving. She flinched when Su-hyeok was suddenly thrown past her, colliding with Cheong-san who had raced back when he had seen his sister and friend being attacked. Another zombie was lunging at Gwi-nam a moment later, as he used his kitchen knife to stab them in the...stomach? Y/N frowned as he then twisted the female zombie around, clutching them by the nape of their neck. She only realised what Gwi-nam's plan was a second too late, pushing herself to her feet just as he pushed the zombie forward. She had no time to dodge them or even try to run away as he threw the zombie at her, it's teeth instantly piercing her neck. Y/N let out a loud scream of pain, feeling the zombie rip a chunk of skin away from her neck. She stabbed the zombie in the back of the head, once, twice, three times, but it was too late. As the zombie flopped the ground, Y/N's hand shakily came up to touch her neck, pulling away to see blood staining her fingers. She was infected.

Cheong-san let out a blood-curdling cry, almost falling to his knees as Su-hyeok held onto him, his own eyes filling with tears. She was going to die. She was dying...

"You really shouldn't have started that fight with Taehyun, Y/N" Gwi-nam spat out, causing Y/N's eyes to widen.

"...You...you were following me before all this?" Y/N realised.

"He told me to kill you...but I figured this would be better" Gwi-nam grinned, as a tear slid down Y/N's cheek.

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A/N: I hope you all enjoyed this crazy chapter! Will Y/N die...maybe not, haha. I'm thinking of adding some Nam-ra/Reader into this story as well to spice things up, what do you guys think? Thanks for all the comments!