Yerim glanced at the clock across her as she silently finished her breakfast.

"So Jaehyun is really not coming here?" Her mother asked dejectedly.

"For the fifth time already, no, eomma.. He has an errand to run this morning, something about the case," Yerim grumbled as she sipped her juice. Truthfully, she didn’t know where Jaehyun is, but guessing from the situation that occurred last night, he probably won’t come this morning. And the following mornings as well, most probably.

"So, you'll be taking the subway to work?"

"No, I hate the subway. I'll probably take the bus. It'll take longer but the bus is slightly more vacant," she said as she put down her spoon and chopsticks.

"Alright. Stay safe and take care, darling. Say hi to your brother, Jaehyun, and the other one, who was it again? Ah, Doyoung! Okay?"

Yerim nodded and picked up her bag before kissing her mother on the cheek and leaving her house.

___

Jaehyun jumped from his bed as he woke up startled from his bad dream which was along the line of Yerim slapping him and barking hateful remarks at him. He groaned and rubbed his face tiredly. He barely had any sleep last night after the cowardice act he pulled off. He stretched his arm and glanced at his bedside clock before jumping off his bed in utter shock.

He's freaking late! He should've been at Yerim's house finishing breakfast instead of in his bed half awake at this hour! He scrambled off his bed and made a line to the bathroom, taking the quickest shower of his life before grabbing a random t-shirt and jeans, putting them on quickly and snatched a jacket from his coat rack before making a run for his car.

Jaehyun couldn't stop cursing as he maneuvered the road, trying to reach her house as fast as he could without exceeding the speed limit. He parked his car haphazardly in front of her house and rushed outside to see her mother whistling cheerfully as she swept her front porch.

"Oh? Jaehyun!"

"Auntie! Is Yerim still home?"

The older lady blinked confusedly, "She just went to work like ten minutes ago. She said you had an important errand to do regarding the case, that's why you couldn't come today."

Jaehyun winced and bowed shamefully, "Oh, I... I thought she would still be here. Is she taking the subway, auntie?"

"No, no. Yerim hated the subway. She's taking the bus. She's probably already at the bus stop now," Mrs. Kim shrugged as she continued sweeping. She had a hunch of what's happening. There's something wrong with the way her daughter acted last night, and this morning as well. Plus, the man in front of her seemed genuinely upset about not meeting her daughter. They seemed like they have a problem between them and Mrs. Kim probably shouldn't in but she secretly rooted for the charming detective so she smiled kindly at him.

"Well… If you rushed, she'd still be there." She nearly giggled when the boy's eyes lit up immediately.

"Really? I'll get going then, auntie. Have a good day!" Jaehyun bowed down numerous times.

She waved her hand as she watched the handsome detective bolted off immediately. Ah, he's truly a keeper.

___

Yerim kicked a pebble as she plopped down on the bench. The bus will not come for another five minutes. She's honestly still a bit upset of Jaehyun's response last night. She admitted it was bold of her to kiss him back, but hey, he started it first. Yerim won't be a fool and she'd willingly admit she has a huge, uncontainable, stupid crush on him. Well, who wouldn’t? He's handsome, kind hearted, charming, smart, and totally her type. She huffed and closed her eyes in annoyance. She was about to reach into her bags for her airpods when a familiar car sped by and stopped abruptly near the bus stop. She blinked her eyes in shock when he saw Jaehyun in his handsome glory rushing out of the driver's side of the car. He looked dashing and delectable in a fitted t-shirt and jeans accompanied by a black canvas jacket— Okay, stop. She’s supposed to be mad.

"Yerim!"

She bit her lip and fisted the hem of her blouse, scooting back defensively.

Jaehyun gulped and held onto her shoulders, "Hey. Uh. God. I'm sorry, Yerim. I woke up late this morning and when I got to your home your mother said you already went to work. I panicked."

Yerim raised her brows in mild surprise. So Jaehyun didn't come for breakfast not because he was avoiding her, but because he woke up late. It made sense with the sight of his slightly wet hair, his fringes sticking to his forehead.

Yerim awkwardly cleared , "Umm, it's okay."

Jaehyun sighed and dropped his hands to her arms, "Look... for last night... I'm terribly sorry. It was a mistake on my part—"

"So, the kiss was really a mistake?" Yerim spoke up timidly.

"H-huh?"

"The kiss. It wasn't sincere, then? It was a mistake, you were drunk, you said. I was hoping it was real though," she mumbled dejectedly, refusing to look at his face.

Jaehyun balked in surprise. Yerim hoped it was real?

"I…" he felt his throat closing up in bursting feelings. He softly squeezed her arms and took a deep breath.

Yerim sighed. She crossed the line. She was hoping too much. She opened , about to apologize when he cut her off completely.

"I… I wasn't drunk! I… I kissed you for real. Because I like you. Genuinely."

There. Now the cat's out of the bag, finally.

Yerim looked up in shock and shyly looked back down, her cheeks adorning a pinkish color now. Jaehyun waited for the girl to say anything back. He was really nervous. God, it felt like high school all over again. Is this how youngsters felt nowadays? His old 32 years old is clearly all over the place when it came to this situation. He’s too old for this . He felt like burying himself beneath the earth core for his stupid unplanned confession.

"I… I kissed you back last night, you know. That means I like you too," she finally mumbled shyly.

Jaehyun paused before he felt a smile growing on his face and then he broke into laughter. He gently pulled her into his embrace as he laughed. Yerim felt his chest rumbled and warmth surged through her body before she chuckled along with him.

"We're stupid, aren't we?" He mumbled against her hair as he buried his face on her head. So, is this how it felt hugging your crush after your feelings were returned? He forgot how it feels after staying single for years.

"We are."

"I should've told you my feelings sooner so we don't have to be awkward like this," he said regretfully.

She shrugged and pulled away, "Well, we've addressed the problem. We're...cool now. We’re totally friends again."

He nodded, "We're cool. Yes. Okay. Uh… But I was hoping I could upgrade our title, you know," he shrugged.

She blushed and giggled, "I wouldn't mind anything, really. Knowing you have feelings for me is comforting enough. Let's just keep things to ourselves. My brother doesn't need another problem on his already full plate."

Jaehyun nodded in agreement, "Until we finish this case. Together."

___

They arrived at the precinct after the dramatic reconciliation at the bus stop. Jaehyun walked her to the morgue and stole a kiss from her cheek before running away, successfully turning her into a swooning mess.

Get a grip, Kim Yerim! You're freaking 30!

The morgue is empty and quiet. Yerim entered her office and settled down comfortably on the couch. Team 2 had requested their help on a stakeout so Yerim decided to lounge on the morgue until the boys came back. Detective Lee Taeyong said a body will come from Gapyeong for her to examine. She was just changing into her white coat when the door to the morgue opened, revealing Detective Kim Jungwoo and a group of CSI officers Yerim didn't recognized.

"Doctor Kim."

Yerim bowed back at the detective.

"This is the body from Gapyeong. We're hoping you could examine it for us."

"I'll gladly do it, Detective Kim. Just leave the body on the examination table. I'll get to it soon."

Detective Kim bowed and the CSI officers laid the body down on the metal table before they bade goodbye. Yerim spent the next three hours in solitude, cutting open the body and sending several samples to the CSI. After typing down the last of her report, she emailed it to Detective Lee Taeyong and Kim Jungwoo before she decided she's sick of the morgue's coldness. She headed upstairs, finding the office vacant since her brother, her newly acquired boyfriend or sort, and their teammate is out to help Team 2. Ever since they got pulled out from the Medicine Murder case, they’ve been tasked to help Team 2 most of the time. She plopped down on her brother's desk, looking at his messy scrawls on a piece of paper. Yerim read the barely intelligible handwriting. If she read them right, it seems like her brother was trying to form a connection between each victim.

Yerim pondered a bit about a crazy theory she figured out the other day. So far, the age pattern still holds up. The date pattern is debunked after Seol Yehwa's body came out of the blue. The tattoo and the used-to-live-in-the-States pattern seemed highly probable. And if she's forcing it, there's another pattern that everyone failed to recognize. Yerim glanced at her brother's messy writing and her eyes dilated when she realized it.

The name. The name is a pattern!

Shin Yunho.

Sung Yoonhye.

Son Yiho.

Shim Yonghee.

Seol Yehwa.

The initials. S. Y. H! They all have different surnames as well.

Shin. Sung. Son. Shim. Seol.

What other surnames out there that started with S?

Soo. Si. Seon. Seok. Seo.

Yerim wrote down each victim's age.

24. 26. 28. 30. 32.

The next victim will be a 34 years old person with the initials S.Y.H.

Yerim wrote down the important piece of clue on a random sticky note she grabbed from Jaehyun's desk. She was about to stand up and head to the meeting room to write it down on the board when an officer came with a box of mails in his hands. She halted on her steps and bowed her head at the officer.

"Mails for team 1! Oh, they're gone?"

"They're out for a stakeout with Team 2, officer. Just leave the mails here, I'll tell the others later," Yerim said.

"Well, fine with me. 2 letters for Detective Jung, one for Detective Kim, and one for Detective Seo! Please sign here, Dr. Kim."

Yerim signed her name and put the envelopes on each guy's desk and her eyes stopped at a light blue envelope on her brother's desk. For Detective Seo Youngho. Yerim recognized the handwriting immediately when she glanced at a crumpled piece of paper her brother stuck on a styrofoam board on his table. The killer's notes. The incoming letter for her brother had the same handwriting as the killer's notes.

Unable to retain her curiosity, Yerim opened the envelope and pulled out a letter, wincing when she realized it was the same paper used as the killer's notes.

Hello, Detective Seo.

Your skills are getting blunt lately. Tired of catching me? Should I make it easier for you then?

Hahyehwa field. 13.00. Today. Don't be late. Don't bring backup. I will know.

See you soon. Try to catch me if you can:)

Yerim took a deep breath as she reread the letter carefully. The killer is luring her brother in. She re read the letter so many times and it dawned upon her that she has seen this handwriting too before. She rummaged through her purse for her wallet and dug through it, revealing a piece of crumpled receipts. She compared the writing to the letter and gasped. It has the same penmanship! She glanced at the header of the receipt.

Aqua Pharmacy

Jaehyun and her were correct! It was somehow related to the pharmacy! She took out her phone and opened the map application, searching for Hahyehwa field. It was located just behind the pharmacy. Someone, either Mr. Seo or Jaewon, is involved in this. Yerim then glanced at the sticky note she just wrote on. 34 years old S.Y.H. One name came into mind.

Seo Youngho.

The killer was targeting her brother all along! Yerim choked out a sob of frustration. Her brother is in danger! She didn't have time to proceed the whole situation when the main door opened and her teammates entered the precinct.

"Hi, Dr. Kim!"

She flinched and fumbled to quickly hid the letter. Her brother should not see this.

"Hi, Detective Lee. Have you received my email? The report. The autopsy results."

"Oh, yes, I have. Thank you very much, you're a savior!" The detective smiled gratefully before retreating to his own office.

"Hey. What are you doing here?" Jaehyun asked jokingly as he approached her.

"Waiting for you guys. I'm bored and hungry," she complained, pouting, hoping Jaehyun cannot read through her anxious state.

"Speaking of that, I'm hungry too. Shall we buy lunch?" Doyoung offered.

"Buy one for me. Anything. I have to go see the chief first," Youngho said as he mussed his sister's hair playfully before walking straight to the chief's office.

"Let's go, Doy. Yerim, wanna come?" Jaehyun invited.

"Nah. I'll stay here. I’m tired of conducting a three-hours autopsy alone. But can I borrow your cell phone, though? I want to play that one game you installed recently. It was fun last time," Yerim asked.

Jaehyun shrugged as he handed his iPhone to her, "Sure."

"Yay! Come back quickly with food!" She grinned awkwardly as the two boys went out again.

After making sure the boys are out of sight, a plan is forming inside her head, a plan to keep his brother safe. Quickly she ran towards the IT department, finding Officer Na Jaemin’s desk pretty easily. The man was whistling while typing a string of numbers on his keyboard.

“Oh, Dr. Kim! How may—"

“Officer Na!”

“Eh? Yes?”

“The application… You were the one who made the GPS tracking application for Shim Yonghee, right?”

Officer Na Jaemin grinned proudly, “Yes! Oh, I haven’t told Detective Seo yet, but I upgraded it for future use! It has a newly added S.O.S button function, it can now send alert directly to Detective Seo’s phone, and it can give a coord—”

“Install it to my phone. Please. Please,” Yerim begged.

“Uh, Dr. Kim? Is there anything wrong? Why would you—” “Just please. I need to try it out. It’s important. Can you connect it with Detective Jung’s phone instead? It will alert the receiver if I pressed the S.O.S button, right?” Yerim said, practically ing her cellphone to the confused officer.

Officer Na looked confused, but he nodded anyway, plugging Yerim’s phone into his computer and Yerim watched the young genius typed away.

“This is your phone, right? What about Detective Jung’s phone? Do you have it, Dr. Kim? I need to—“

“Here!”

Officer Na awkwardly grinned, accepting Jaehyun’s phone. Yerim watched as Officer Na tinkered with their two phones before handing it back to here.

“Here, Dr. Kim. This is the S.O.S button on your phone. If you tap it, even just once, it will send an alert with a loud alarm on Detective Jung’s phone, along with your coordinates. I just hope that there’s no bug, because I just finished developing it two days ago. The graphic UI is still… ugly, and the alarm sound might be outrageous, but it’s much better than my previous creation,” Officer Na explained thoroughly.

Overwhelmed, Yerim hugged the younger guy, “Thank you so much, Officer Na!”

“Just call me Jaemin, but you’re welcome!!!” the officer yelled as Yerim ran back to her brother’s desk.

She jotted down a note and stuck it on Jaehyun's desk, hoping the smart and observant guy would figure it out, before she left the precinct with fear but also determination.

___

She ran. She needed to relieve the tension within her so she ran to the field. She has 5 minutes before 13.00 comes. She took her time taking pictures of her surroundings. It might be a useful clue. She quickly shoved the phone to her back pocket and looked around warily.

"Well, well, look who we have here?" Yerim turned back rapidly and gasped when she gazed into a familiar man.

It was Mr. Seo! Jaehyun and her were both right all along! It made sense. He’s a pharmacist. He had the knowledge and the access to drugs. His built was consistent to the tall and lean man that Jaehyun saw. His built was sturdy enough to snap people’s bones into unimaginable position.

"I believe I sent the letter to Detective Seo Youngho, not you."

"He hasn't read your letter. I did," Yerim answered firmly.

"Why did you come, huh?"

"I want to keep my brother safe," she said curtly.

"Brother?!"

"He's my step brother."

Yerim swore she saw rage on his eyes and he was charging at her and the next thing she knew, a piece of cloth covered and she saw black.

Jaewon was cleaning the counter when the entrance door was slammed open and he shrieked when he saw his boss carrying a female body like a sack. He was worried when the man told him to close the pharmacy early. His suspicion was proven correct. He balked when he noticed the unconscious female.

"That's… the girl from the precinct! Sir…"

Mr. Seo growled, "Shut your mouth and guard the place. Try running away, and your body will be the next one I send to the police office."

"Y-yes sir…"

___

Yerim blearily opened her eyes, feeling slightly disoriented.

"Chloroform. ing chloroform," she muttered groggily.

She looked at her surroundings. She's in a… bathroom? A big one. She tried to stand up, albeit futilely, since her hands are bound behind her back and her legs are tied together with a piece of rope. She then glanced at her hair that fell on her shoulder and shrieked.

It was black. The man ing dyed it! And she knew how bad of a ing dye job he usually did. And with dyed hair she realized one more thing.

.

She's the next victim.

She tried to tone down the panic that rises within her and instead tried to wiggle her way out of the ropes that bound her. Even if she couldn't get out of it, at least she can loosen it up. She then tensed up when the door opened, revealing Mr. Seo, a wicked smile on his face. She winced when she saw he was already using gloves and also long-sleeved clothing. It would be hard to get her hands on him. If she could scratch him, she could at least get his DNA under her fingertips if he ended up killing her.

Goddamn it. That man was smart.

"Youngho's sister, huh? That wicked woman adopted you?"

Yerim furrowed her brows. "I don't know who's the wicked woman you're talking about but Youngho oppa's mother is my mother too, she gave birth to me, and she's nowhere near wicked," she spat.

"She gave birth to you? With that bastard? You bastard child!"

Yerim screamed when the man suddenly charged forward and slapped her on the cheek. She felt her left cheek stinging painfully after the loud slap.

"My father is not a bastard," she said through gritted teeth.

Mr. Seo crouched down and held her chin, "He ing is."

Another slap.

Yerim tensed up on her position when he saw the man standing up into the bathroom counter, pulling up a glass and filling it with tap water. The alarm inside her head ran when he took out a tablet from his pocket, crushing it with the back of a spoon before stirring it into the glass of water.

She writhed in fear when he shoved the glass to . "Drink."

She shut and shook her head firmly. God knows what's inside it.

"Drink!"

She shook her head again fervently.

He shook his head and forced open, forcing the weird tasting liquid into . She choked on it and he laughed evilly.

"You'll get caught. You'll ing get caught," Yerim screamed.

The man laughed boisterously. "Good. That's ing good. I can't wait to see my boy Youngho again," he spat before slamming the door close.

Yerim quickly used her hands to take out her phone from the back of her pants. Her fingers trembled as she opened the GPS SOS app Officer Na installed on her phone a few hours ago. She sent the SOS code and sighed. She leaned against the wall and kicked her phone somewhere not visible, afraid Mr. Seo would take it away if he sees it.

Nothing happened. No sound, no nothing, whatsoever. She was this close to crying. It finally hits her that she’s facing an A-list genius serial killer. She could possibly die today.

Slowly, she felt drowsiness gulfed upon her. It's the end. But at least her brother's safe. And that's what mattered.

___

Mr. Seo returned after thirty minutes, grinning when he saw the unconscious girl sprawled on the bathroom floor.

"I'd love to see how Youngho would react when he saw her baby sister shipped to the precinct." He cackled before picking her up and dunking her into the filled bathtub.