At the same time Hoya was interviewing Park Hana, Myungsoo was at his desk reviewing notes on Lee Minhee's murder. He squinted at the paper, trying and failing to stifle a large yawn. To say it had been a late night would be an understatement. After speaking to Sungyeol about everything, he'd staggered home at nearly four in the morning. Seeing as he had to leave for work at 7:30, he'd tried to get as much sleep as he could in the next few hours... But of course, after the events that had happened, he hadn't been able to close his eyes for a second. Instead, he'd stared at the ceiling in a state of exhaustion mixed with worries, wondering what he was going to do about the case and the situation with the rookie.

Just as his eyelids were about to droop shut, a cup of coffee landed beside his hand. 

"Here, drink this," a voice said as Myungsoo jerked back. Blearily, he lifted his head to see Sungjong blinking owlishly at him. 

"Thanks," the ravenet muttered, reaching for the beverage. He took a large gulp, not bothering to wait for the drink to cool down. The scalding liquid almost burned his tongue, but he gladly welcomed the heat. It was enough to make him feel much, much more awake than he had been earlier. 

"Late night?" Sungjong asked, grabbing a nearby seat. 

"You could say that." Myungsoo glanced his way as he took another sip. It had been a while since he'd last spoken to his friend, he realized with a jolt. What with the investigation and Sungyeol's disappearance-slash-return, he'd barely had enough time to even think about Sungjong, let alone find the opportunity to have a serious talk with him. He inwardly winced when he remembered their visit to Yangsan and their parents' graves. He knew he had to talk to Sungjong about that- about the kiss- sooner or later. It wasn't fair to either of them, especially Sungjong, to keep putting it off. 

'No time like the present.' Taking a deep breath, Myungsoo set down his cup and looked at his companion square in the face. 

"Look, we need to talk."

"I'll say," Sungjong replied lightly. "I haven't seen you in ages, and we're supposed to be working on the same case."

Myungsoo shook his head. "Not that. What I mean is, we need to talk about that- what happened in Yangsan- when we visited the cemetery-" 

"Oh. That." Sungjong looked at his hands. The atmosphere of the room was quickly becoming awkward, suffocating. It was enough for Myungsoo to wish that he'd never brought up the topic in the first place. "Maybe we should forget about it for now-" 

"I realize I've been ignoring you," Myungsoo interrupted. He figured it was best to speak while his confidence hadn't yet been shot. "And I'm sorry. You're my best friend and I don't want to lose you..."

Sungjong's voice was soft. "But that's all I'll ever be, right? Your best friend. Nothing more, nothing less." 

The older agent faltered. He honestly wasn't sure what he was supposed to say in response. Yes? No? I'm sorry again? He didn't know; he wasn't good at these kinds of situations. "I..." 

"It's okay. You don't have to say anything else." Much to his surprise, Sungjong lifted his gaze and smiled. There was no sign of melancholy; no anger, no resentment. It was just that, a simple smile. "I knew that from the day we met you would never feel the same way towards me. You were always looking out for me, and maybe I took that too much to heart. But I can't force you to change your feelings and I don't want to lose you as a friend, either. So I think it's best if we forget it ever happened and move on from the past."

"I see. If that's what you want." Myungsoo studied Sungjong's expression. His words seemed sincere, but the detective in him couldn't help but question them. Were they going to be alright? Was their friendship really going to be fine? Or, like a piece of paper crumpled and smoothed out again, were there going to be awkward creases that prevented it from being the same as before? The agent didn't dare breathe aloud in fear of ruining things any further.

"Seriously, stop looking at me like that!" Sungjong scolded him. "I've come to terms with it. You'd better not treat me any differently than before, you got that?"

"Okay, okay, sorry." Myungsoo felt the corners of his mouth tugging upwards. Same old Sungjong, naggy as ever. He reached for his coffee, thankful and relieved that things were slowly returning to normal. "So how's everything else with you-" 

"There you are. I've been looking all over for you," a voice behind him interrupted. Myungsoo turned his head to see Woohyun approaching them, hair a mess and shirt only half-tucked into his pants. He'd been so engrossed in his talk with Sungjong that he hadn't even heard the older inspector enter the room.

"Hey, Woohyun. Did you need something?" Myungsoo asked. He suddenly remembered his promise to fill Woohyun in on the situation with Sungyeol. With a quick glance at Sungjong, he silently prayed that the new arrival would have the sense to ask for the details when they were alone. Sungjong was his friend, yes, and there were usually no secrets kept between them... But at any rate, it was a topic Myungsoo wished to discuss out of ears and behind closed doors. 

Woohyun scowled at him. "You're looking unusually chipper this morning. How'd you sleep last night, you little bastard?" There were bags under his eyes but the message in them was as clear as day: You owe me an explanation.

Myungsoo gave him a tiny nod. He pointed at the steaming beverage on his desk. "Not so great, but Sungjong was nice enough to bring me some caffeine." 

"Any chance of me getting a cup?" Woohyun asked, squinting at the two seated agents.

Sungjong snickered. "As they say in Russia, fat chance, Igor." 

Woohyun opened his mouth to argue back but before he could do so, Myungsoo interjected with a cough. He was already tired enough from his lack of sleep. The last thing he needed was to hear these two bicker so loudly beside him. 

"Was there something you needed, Woohyun? I'm sort of in the middle of something here." 

"Yeah, actually." With a final sneer in Sungjong's direction, Woohyun jerked his thumb towards the door. "The minister of that church called. Said he needed to talk to us about something. I figured since it was initially your case, you guys should be the ones to go." 

Myungsoo looked at his younger friend. "You feeling up for a little trip?" 

To his surprise, Sungjong shook his head. "You and Woohyun go instead. There's a new lead I wanted to check out today."

"Alright then." As he gathered his notebook and jacket, Myungsoo realized that this would give him the opportunity to speak privately with Woohyun. And judging by Woohyun's lack of protests at having to work so early in the morning, the older agent was thinking along the exact same lines as him.

As he followed his dishevelled-looking friend out of the room, Myungsoo glanced over his shoulder. "I'll talk to you later?" He didn't know why his words had come out as a question.

Sungjong looked back at him with that same simple smile from before. "Yeah. See you later."

-------

As they walked towards Woohyun's silver lexus, the elder detective shoved his car keys into Myungsoo's hand.

"Here, you take the wheel. I can barely walk right now, let alone think about driving." 

"How long did you stay in the bar?" Myungsoo asked, both curious and amused. He unlocked the car and peered at his friend. If Woohyun was feeling hungover- or maybe just really tired and distracted from everything that was going on- then he couldn't help but wonder about Sunggyu's condition that morning. He knew the boss was at work, but the agent hadn't seen him when he'd signed in himself. 

Woohyun groaned and opened the passenger door. "An hour or two after you left. I don't remember, I was too busy trying to keep Sunggyu from drinking himself to death." Then, despite the obvious headache he was suffering, he added in a smug voice, "If you think I look like crap, wait 'til you see Gyu. He was wearing his jacket inside out and I don't even think he washed his face when he left his house." 

Myungsoo settled himself behind the wheel. "Poor Sunggyu," he said with a tired laugh. The coffee he'd received from Sungjong had done wonders for his sleep-deprived brain, but it hadn't quite been enough to shake the bleariness out of his head. Perhaps after they finished their business at the church, he would grab a few lattes for himself and Woohyun. "It's been a long time since he's had a night out, right?" 

"If you ask me, it was way overdue." Buckling his seat belt, Woohyun leaned back and closed his eyes. "Now hurry up and tell me why you left us last night. It's about Sungyeol, isn't it?"

Myungsoo complied, grateful for the privacy they had in the vehicle. 

Once he had finished detailing the entire story, Woohyun let out a low whistle. "Holy . So that's what Sungyeol's been dealing with... I knew it must have been something serious, but I never imagined it would be anything as messed up as that. So Park Kyung's his adoptive brother?"

"That's what he told me." Myungsoo glanced into the rear-view mirror and switched to the right lane. His recounting had taken longer than expected- only five more minutes and they would arrive at the chapel. "Sungyeol was the one who left and then went back to confront him, but Park Kyung never once tried to contact him during those thirteen years. I wonder why...?"

Woohyun rested his cheek on his palm as he watched other cars pass their lane. "If he's as single-minded and childish as you say he is, then he probably just lost interest. But I have to admit, Lee Sungyeol is one tough kid. I can't believe he's still standing, let alone working in a career that's as emotionally and physically demanding as ours. Anybody else would have suffered breakdowns or even followed the path of the abuser, but Sungyeol... Jeez. It sure does explain a lot though." 

"Does it? Like what?" 

"Like why he's as closed off as he is," Woohyun answered simply. "He's afraid of letting anyone inside and being hurt again." 

The younger man mulled over Woohyun's statement. He wasn't wrong, Myungsoo brooded, but he had a feeling there was more to Sungyeol's distant personality than his fear of getting hurt. It bothered him that he couldn't explain what it was, though. It bothered him more than he wanted to admit.

"So what are you going to do about him?" Woohyun suddenly asked, breaking the impromptu silence. 

"I'm not sure." Myungsoo was thankful for the change in conversation- he didn't want to linger on the topic of the newcomer's past any longer than he had to. "I told Sungyeol to lay low for a while- or at least until we get our heads straight- but you know as well as I do that he can't hide at home forever."

"We should tell Sunggyu, as well," mused Woohyun. "He'd want to know." 

Myungsoo glanced at him with a bit of surprise. "You think it's safe to tell him?" Not to second doubt the branch director, but he wasn't sure if it would be wise to let him in on the situation. While Sunggyu was an extremely intelligent and fair leader, the ravenet was hesitant to expose to him a man who was technically missing and wanted by the CSI. 

Woohyun shrugged a shoulder. "Yeah. It'll be fine. Just like I trust Sungyeol, I trust Gyu to do what's right for all of us, including the kid. Don't worry; he won't throw any suspicious or unwanted attention Sungyeol's way. At any rate, Chen and Kahi have no evidence to support their claims."

"... Alright then." Myungsoo concluded after a moment of quiet consideration. He supposed that would be the best thing to do, telling the leader about everything that had happened. He just hoped he wouldn't come to regret his decision. "We'll tell him when we get back."

They didn't speak another word until they'd pulled into the parking lot of the chapel.

-------

Myungsoo knocked on the door of the church's main office. "Hello, Father Kim? It's Kim Myungsoo and Nam Woohyun from the CSI. Are you busy now...?"

"Not at all, come in!" the pastor's voice called from inside.

Twisting the handle, the agent stepped into the room with Woohyun trailing behind him. There was Kim Junsoo, sitting at his desk with his usual minister robes on, and surprisingly sitting in the chair in front of him was a young man in his early twenties. His face looked pleasant enough but his eyes were shrewd and full of wit, telling the world that he was able to see through whatever lies it told him. What he was doing there, Myungsoo had no idea. He figured it had to do with the reason they were asked to come in the first place.

He cleared his throat and offered his hand to the pastor. "It's good to see you again, sir. How have you been doing these days?"

"Good, good, thank you for asking." Smiling, Kim Junsoo rose from his seat to properly greet his guests. He first exchanged handshakes with Myungsoo and then with Woohyun, urging them to make themselves comfortable in the spare chairs. 

Once they had settled down, he finally introduced to them the unfamiliar young man.

"Gentlemen, I'd like to thank you for taking the time to visit us," he began. "I can't imagine how busy you must be at the moment. I hope this won't take too long- I wouldn't want to keep you from your work. 

"This is Lee Jungshin. He's been attending this church ever since he was a child." Hearing his name, Jungshin smiled and bowed his head. "He has something that may be of use for your investigation."

"Oh? And what might that be?" Woohyun asked, perking up.

Jungshin rummaged through his bag and pulled out a memory stick. "Footage of Lee Minhee days before her death," he answered, expression turning solemn. He saw that the two detectives were exchanging startled but meaningful glances with each other. Before they could cast their suspicions on him, he quickly added, "Look, don't think I'm some kind of creep who liked taping her. It's just a coincidence that I have this, that's all. I'm a third year student in film and cinema studies. For the past month I've been working on a still-life movie here at the church."

His project, the student proceeded to explain, was meant to focus on time perception in the setting of his choice. He'd decided to film it here in the chapel as it was a place he was quite fond of and respected greatly.

"Throughout the past few weeks I set up cameras around the sanctuary." Jungshin held up a mini camcorder, as if wanting to prove that he was, in fact, a film studies major as he'd claimed. "I set them to record for ten hours straight every day, so I could capture images of both the emptiness and people coming in to give their prayers. Nothing too in-your-face, of course. My work is highly based on the element of discretion." 

"So how does Lee Minhee play into this?" Woohyun asked with a touch of impatience. 

Jungshin handed him the USB. "From my understanding, there's not a whole lot you know about her. Minhee lived alone and her parents are dead. Her friends and teachers probably told you that she was a great kid, really nice, but how's that supposed to help you connect her to the killer?"

In front of them, Father Kim looked apologetically at the inspectors. "I'm sorry. I told him that you asked a lot of questions about her background when we first spoke. I didn't think it would be a problem if he knew that much."

"No, it's fine," Myungsoo reassured him. The pastor hadn't told Jungshin anything confidential, but a guy as sharp as him was bound to pick up details from the bare minimum he was given. The agent turned towards the observational male. "Is that why you're giving this to us? For us to personally see what she was like when she was alive?" 

"Yeah," Jungshin nodded. "The people who I caught on tape weren't aware they were being filmed, so everything you'll see is the real Minhee. She was here a lot, even more than I was. I think there's at least sixteen hours' worth of footage there. I figured if you analyzed her body language, her facial expressions, then it could take you a step closer to uncovering the why of your investigation." 

Woohyun shoved the flash drive into his pocket and quirked a brow. "You'd make one helluva detective, kid. Are you sure you don't want to go into criminology instead?" 

Breaking his seriousness, Jungshin laughed. "Thanks, but I think I'll leave that to you. Movies have been my passion ever since I was young."

"Thanks a lot for your help, Jungshin." Myungsoo stood and shook hands with the student. "I think we'd better go now and review the footage. Do you want the USB back when we're done?"

"Nah, don't worry about it," the young man declined. Having risen from his own chair, he was now exchanging farewells with Woohyun. "I can always buy more if I need to. Besides, the original shots are uploaded on my computer at home." 

The two crime scene agents bid final farewells to the student and the pastor, and before they knew it they were back in Woohyun's car making the return trip to headquarters. 

Half an hour later they found themselves settled in Audio Tech Room Three, the memory stick plugged into a computer and coffee cups in hands (Myungsoo had wisely stopped by the lounge for caffeinated drinks before trudging to the tech room). 

"I guess we'll have to talk to Sunggyu later then," Woohyun commented as he watched his friend fiddle with the keyboard. 

"We'll go after we finish this." 

"Sixteen hours... I don't think I have it in me to stay for even twenty minutes." 

Myungsoo smiled wryly. "We don't have to watch all of it." As he waited for the clip to load, he took a much-needed gulp of his beverage. "We can just watch the first few minutes and fast-forward through some of it, to see Lee Minhee for ourselves, then ask the intelligence unit to analyze it."

"I bet Youngjae would just love for us to add to his workload," snickered Woohyun. He brought his own cup to his lips and downed half of the lukewarm liquid in one go. 

"Maybe if we ask nicely. Now be quiet and pay attention." 

For the next ten minutes they were silent, peering at the monitor with concentrated- and in Woohyun's case, slightly bored- expressions. Jungshin had taken the initiative to cut and paste many of the scenes, only giving them footage in which the deceased girl could be seen. During the first few moments she had done nothing but gaze up at the ceiling of the chapel. She had her hands clasped together and appeared to be deep in thought, features contorted in a melancholy yet determined expression. 

Suddenly she dropped to her knees, placing her entwined hands in front of her and closing her eyes in a prayer. Her lips moved as words spilled from them but there was no audio of her voice. Myungsoo frowned. Either the camera had been set on silent mode or Minhee herself had not made a sound.

"Can you start fast-forwarding now?" Woohyun spoke up. He had already drained his cup and looked like he was wishing for a refill. "It's not like we can hear what she's saying anyways."

The younger detective did so. Already he had a sense of the kind of person Lee Minhee had been. A devotee of religion, obviously. Somebody who was humble enough to ask for forgiveness- but not for herself, Myungsoo remembered. According to the minister, she had continuously visited the church to pray for the spirits of her parents... What had Kim Junsoo said about her praying for them, again?

"I recall one time when she mentioned something about 'atoning for their sins.' I wasn't quite sure what she meant by that, and to be honest, I still don't know today."

Exactly what kind of sins had Minhee been referring to? They'd gone over every nook and cranny in her parents' personal, social, and work histories. Nothing they'd discovered would have counted as an immoral violation, not even close. Just what had the young girl meant by their sins...

Woohyun, who had been sitting back in his chair with his arms crossed, suddenly leaned closer to the computer screen. "Hang on a second. Are you seeing what I'm seeing? Is that..."

Instinctively Myungsoo clicked the pause button. As he stared at the scene that had made Woohyun jump forwards, all feelings of frustration dissipated from his mind.

"Sungjong?"

There was no mistaking it was him. On the screen, Minhee had risen from the ground and was talking to the slender CSI agent. She had her back turned to the camera so it was hard to guess what she was saying, but thanks to the high definition of the camera they could see that Sungjong was wearing a politely sympathetic yet curious expression. 

Myungsoo couldn't tear his eyes away from the screen. What the hell was Sungjong doing there? He had never mentioned that he'd personally known or ever spoken to Lee Minhee... In fact, as with all of their previous cases, he'd treated this one with a purely professional demeanour, never giving the slightest hint that he had known her as a person and not a victim.

Woohyun wordlessly reached over to resume the clip, this time at normal speed. They both watched silently as Sungjong and Minhee continued their conversation for the next five minutes or so, until finally they left the chapel room together.

"We need to talk to him," Myungsoo said as soon as it was over. He quickly went back to the spot where Sungjong had appeared in the video and began watching it again. He had to be sure... There they were, Minhee and Sungjong, talking as strangers and leaving as aquaintances... Or had they known each other from before that day? 

Woohyun had already pulled out his mobile and was dialing a number. "He's not answering." 

"Keep trying." 

"All I'm getting is the voice mail." Woohyun frowned. All signs of exhaustion and boredom had disappeared, leaving behind a terse expression on his face. "Try calling him on your phone. Maybe he's just ignoring mine."

Myungsoo did so but when he tried, he, too, received no answer. He hit the pause button on the computer and stood from his chair. "We need to find him." The sudden development in the case was making his head spin. What had Sungjong been doing with Lee Minhee? Why had he been talking to her? Perhaps he was making a big deal out of nothing and was doubting his friend for no reason... Nonetheless, they needed to speak with him now and if it came to it, with the pastor and Jungshin, as well. 

As he led Woohyun out of the room, Myungsoo tried to think of the places Sungjong could be found in. All he had said this morning was that he had a new lead to follow; he hadn't mentioned anything about where he would be working. Myungsoo ignored the fact that his friend hadn't answered any of their calls- he was probably too caught up with that lead of his- but he had a bad feeling that Sungjong wouldn't be found anywhere in headquarters.

In fact, he had a horrible suspicion that Sungjong wouldn't be found anywhere at all.

-------

Somewhere in another part of the city, two men were sitting in a cafe together. One of them was hunched in his seat, eyes narrowed in a guarded expression, while the other was sipping from his cup in a completely relaxed manner. He seemed unaware of the suspicious looks his companion was shooting in his direction- in fact, he looked rather pleased with himself, as if thinking about a joke that only he knew the punchline to. 

The relaxed man set down his cup. "Aren't you going to drink your coffee?" he asked, gesturing at the other man's untouched beverage. "I can't imagine that you were given such luxuries in the station cell. Or maybe you'd like a sandwich instead. Are you hungry?" 

The only response he received in return was a glare. 

Picking up his drink, he studied his companion from the corner of his eye. Time had taken a hefty toll on this man, he mused to himself. It had been more than twenty years since they'd last seen each other, and if he hadn't known better, he almost wouldn't have recognized his friend. Deep wrinkles lined his forehead and grey had completely taken over what used to be a head of black hairs... But the biggest change, he decided, was the defined stoop in his shoulders. They were bent low, drawn closer to his body, as if carrying the weight of an invisible burden known only to the carrier. 

And he had a feeling he knew exactly what it was that burdened Kim Jongin so heavily.

The man took another sip of his coffee and set down the cup. "Drink, old friend. I'll go buy you something to eat." Perhaps after a light meal, their conversation could finally get started.

Just as he was about to rise from his seat, his companion broke his silence. "Don't call me that."

The man raised a brow. At last, a reaction. "Don't call you what? Old friend? But we are old friends. You and I go a long way back, Jongin. What am I supposed to call you instead?"

"We're not friends," Jongin spat out. "We never were. And now you and I have nothing to do with each other. I thought I made it clear that I never wanted to see any of you people again, least of all you, Yixing. After all these years, what more could you possibly want from me?"

The man called Zhang Yixing leaned back in his chair to appraise the male before him. "You speak harsh words," he said after a moment, ignoring the question of his intentions, "For someone who was so eager to help our cause." 

Jongin clenched his fists. "It was a mistake," he said bitterly. "A terrible, terrible mistake. I never should have listened to you. I should have just left your office as soon as you told me what you wanted to do. But like a fool, I went along with you and the others and committed the most evil deeds a man can ever do. Now I spend all of my waking moments repenting for what I did." 

Yixing's voice was almost amused. "And how far along have you gotten?" 

"Does my suffering entertain you?" Jongin shot him a look that was both incredulous and infuriated. "After everything we did- after everything you did- how can you just sit there and smile like it's meant to be funny? Don't you feel even the slightest bit of guilt and regret?"

An unreadable shadow crossed Yixing's face. He said softly, "The only thing I regret is not succeeding with our plans." 

Jongin opened his mouth to protest, to call him a monster, but after a while pressed his lips back together. It wouldn't be of any use to insult him that way. To call out a person as dehumanized as Zhang Yixing wouldn't make any difference at all. He knew from experience that his words would only go through one ear and fly out the other.

Instead, the elderly man crossed his arms. "Why did you bail me out?"

At the change of conversation, the expression in Yixing's eyes lightened up. His face was still serious, but the darkness covering his features had disappeared. "Ah, yes. Your arrest. I was quite surprised when I heard you'd been taken in. Shooting a detective, was it? Did you really do it in self-defence? By the way, a simple thank you wouldn't go amiss." 

"I never asked you to help me," was Jongin's immediate response. 

"Of course you didn't," Yixing said dryly. Then, as if wanting to shed his casual exterior, he leaned forwards and spoke in a low voice. "We need to talk. I've been trying to get in touch with you for nearly a month now. Why did you ignore all of my calls and letters?"

Jongin shook his head in an adamant refusal. "There was no reason to. We have nothing to talk about." 

"Yes, we do." With fluid motions Yixing pulled a creased piece of paper out of his pocket. Eyes flashing, he unfolded it and threw it to Jongin's side of the table. Jongin couldn't help himself- instinctively, he looked down to see what it was. He regretted his actions at once. There was only one thing on the crumpled sheet: a picture of a small mockingbird, dead with blood matting its feathers and eyes staring blankly ahead.

Yixing continued, "Five weeks ago, I received this in the mail. Obviously, I was surprised and wondered if it was prank mail at first, but then I realized: Case 21. Project Mockingbird. There's no mistaking what this letter is about. It's a warning, and the message is clear. Somebody's discovered what we did and whoever they are, they want us dead like this bird."

"No, no, no..." Jongin muttered, desperately trying to fight the chill that was running down his spine.

"Stop lying to yourself," Yixing scoffed. He peered in Jongin's direction with grim eyes, yet had a strange air of smug satisfaction around him. It was almost as if, as grave as the situation was, he was enjoying watching the other man tremble in fear. "As soon as it clicked I tried getting in touch with the others- the ones who were still alive, anyway. Taehyun and Hwayoung weren't answering my calls and Seonwoong, that old fool, had the same reaction as you. Now they're all dead, including that Minhee girl. And you know why she was involved. Come now, Jongin. I know you're not stupid. Don't you see the pattern here?" 

"There's no pattern!" Jongin snapped and pushed the paper away. He could feel a bout of hysteria threaten to escape him, but he forced himself to remain calm. There was no need for him to panic. Everything would be fine. "It's all a coincidence. They were just in the wrong place at the wrong time. You've deluded yourself into thinking something ridiculous, as usual." 

His companion drummed his fingers on the table surface. "And you've deluded yourself into thinking this has nothing to do with you, as usual. Get a grip, will you? You may be pretending life is fine and dandy now, but you know as well as I do that you're far from safe. He's watching us, Jongin. You and I are the only ones left."

Jongin straightened his spine, but before he could give a retort, Yixing beat him to it. 

"I've read all of the news reports on this Mockingbird killer. I went over the victims' deaths and histories in fine detail trying to find another reason for targeting them, and each time I concluded there was only one single possibility: Case 21. It's the only motive the killer could have for wanting to murder those people." 

"You're wrong," was Jongin's automatic response. He'd intended for it to be a snarl but instead it came out more like a croak. "Case 21 was buried in the past. I left it behind and I'm sure the others did as well. Besides, we ensured it would remain a secret from the public-"

Yixing gave him a pitying look. "That's the thing about secrets," he said quietly. "They never remain secret, no matter how long it takes for them to be uncovered." 

Jongin slowly moved his arms to his sides. He considered the limited options he had for his next move: one, he could argue with Yixing about how foolishly fantastical his ideas were, or two, he could leave the cafe and pretend none of this conversation had ever happened. After debating in his mind for a minute, he chose the latter. He knew that even if he sat there and talked with him all day, Zhang Yixing would not budge from his opinion.

The elderly man pushed his chair away from the table. "Believe what you want, Yixing. You can think or do whatever you want to, but leave me out of it. I have no wish to be dragged into your sickening games anymore." 

Rather than look defeated or frustrated, Yixing raised his empty cup in a mock salute. "But you were so keen the first time." 

Jongin chose not to dignify his remark with an answer. With a final wary look, he turned and walked towards the exit, leaving behind a cold coffee, a crumpled letter, and a smiling man who was watching his every move.

He had only gotten four steps away before he heard that smiling man speak again.

"Oh, and Jongin? One last word of advice," Yixing called after him in that same lighthearted voice. "Be careful or you might be next." There was no trace of malice to be heard, and Jongin knew if he glanced back he would see the grin still on Yixing's face. But as friendly as it sounded, it seemed more like a warning of sorts... No, not a warning.

It sounded like a threat.