It was nearing quarter past two in the morning, and Lee Sungyeol was still very much wide awake.

He was in the kitchen of his apartment, sitting at the table where he usually ate his meals alone. The lights were on, but that was the only thing to indicate his presence. The tall man wasn't really doing much of anything- all he did was sit on his chair, eyes staring at the fridge on the other side of the room but mind focused on something else entirely.

Kim Myungsoo. That weird, outspoken guy. Just his name alone was enough to make Sungyeol's head hurt. Before, he would have merely raised a brow in mild amusement and barely-there interest at the thought of the raven-haired inspector. But now, after their last conversation or argument or whatever the hell it had been, Sungyeol didn't even know what  he thought about the frustrating man.

Honestly, what was wrong with that guy? Why was he so stubborn and persistent about everything? Sungyeol had told  him to stay away. He clearly remembered warning Myungsoo to back off and forget any chance of them becoming friends. "I didn't come here to make friends, and I don't plan on doing so any time soon,"  had been his exact words. And yet, Myungsoo ignored him. Like a moth drawn to a burning flame, he disregarded the danger and pain Sungyeol would give him, looking only at the mosaic of red, orange, and yellow lights illuminating ahead.

Searching in the dark with blind, misguided sight, wanting to find the truth that takes cover in the night.

And, if he wanted to be truthful, that  was what was making everything so goddamn difficult for Sungyeol.

The newcomer closed his eyes. An inaudible sigh passed his lips, drowned out by the hum of the refrigerator. Kim Myungsoo... If he kept his eyes shut, Sungyeol could picture the older man in his head as clearly as if he were seeing him in person. The sharp, sculpted features of his face, the piercing eyes that were constantly seeking answers, the short yet unkempt strands of his midnight hair...

"I shouldn't be caring for a guy like you. But... For some reason, I feel like I have to. Like I'm meant to do this. Something's holding you back from being your true self, Lee Sungyeol, and I'm determined to figure out why."

Sungyeol abruptly shook his head. Snapping his eyes open, he realized that his right hand had risen up, almost like it had subconsciously reached out to touch the image of Myungsoo. He yanked his arm down without wasting another second. The silent man willed himself to erase the image from his mind. What was that all about?  Kim Myungsoo was nothing more than an ignorant fool. How could just the mere thought of him  bring such a reaction out of Sungyeol, who had promised himself never to let anyone inside of his heart again?

Because, a voice in the back of his head whispered silkily, Maybe he was right. Maybe he really  is meant to change you, to tear off your mask for the world to see.

Sungyeol shook his head again. How frustrating this was all becoming. When he'd entered his kitchen at ten o' clock earlier, he had only intended to fetch a glass of water before going back to his laptop. But here he was, four hours later, sitting at the table with no glass and only nonsensical thoughts for company. Sungyeol didn't know how it happened. He didn't know how he ended up musing over his idiotic colleague for so long. But finally, after much consideration, the newcomer wordlessly concluded that any more thinking about Kim Myungsoo would lead to major brain damage, and he was better off going back to solving the investigation. He would deal with Myungsoo later, if need be.

His thoughts- forcibly- drifted off towards the day's events. He and Myungsoo had gone to the church at Sungjong's request, where they'd found absolutely nothing to aid them on Lee Minhee's case. Then they'd returned to HQ, where Woohyun had greeted them with news of the agents' conference.

"They found someone who may or may not be connected to the dead birds. He's an underground trafficker, supposedly one of the best in the black market."

Sungyeol narrowed his eyes. "Park Kyung..." he murmured, although his clenched fist didn't match the quietness of his tone. Briefly, he replayed the last scene in his mind again. When Woohyun had uttered Park Kyung's name, Sungyeol had had to use every ounce of control in his body not to react. He'd made sure he had only looked on with an appropriate amount of interest, although beneath his facade, he wanted so badly to punch the wall and gain bruised, broken fingers in return, so they could be a physical representation of the turmoil he was feeling inside-

In that moment of chaotic thoughts and hurricane emotions, Sungyeol made up his mind. It was a split-second decision- very rash, sudden, and extremely likely to be dangerous- but he didn't see any other way out. It was an inevitable act. If they ever wanted to win the game of the Mockingbird, Sungyeol would have to be the first pawn to make a move.

The tall man stood up from his chair. He crossed the kitchen floor, making sure to turn the lights off, then entered the adjoined living room. Swiftly, he grabbed his jacket from the sofa and pulled it on in a single fluid move. As he did, Sungyeol felt a thin, but stiff object in the coat pocket. He automatically reached down to retrieve it, already knowing what the item was.

Sure enough, it was his CSI badge. Sungyeol looked at it, a leather-wrapped piece of plastic identification. His picture stared back at him, unsmiling, straight-faced, sending him an unspoken message with guarded eyes. You said you would never go back to him, no matter what. Have you forgotten what he did already? Are you really going to let that hell back into your life?

"I don't think I have a choice," Sungyeol said quietly. He placed his badge on top of the living room table, which was ironically where he'd left his case notes spread out. Then, without looking back, Sungyeol strode across the room, turned off all of the lights, and slipped through the apartment door. It was only when he heard the click  of the door behind him that he realized how empty his jacket pocket felt. He had gotten used to carrying the weight of his CSI badge around, so it was rather strange not having it in his pocket. But, oh well. No matter.

He wouldn't be needing it where he was going.

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Somewhere else in the city, another agent was also spending his beauty sleep as a night owl. Currently, the time was 3:04 AM, and Bang Yongguk was taking a nice, relaxing stroll around his favourite park.

To readers who are shaking their heads at this scene, or chuckling at what might be considered typical Bang Yongguk behaviour, do not misunderstand. The weaponry agent was not out on a late-night jog, nor was this a part of his nightly routine. It was simply that Yongguk had too many thoughts keeping him awake, so he'd decided that some fresh air would help clear his mind.

Yongguk absentmindedly followed the curve of the path. He wasn't really too worried about the danger of being out so late- he was Bang Yongguk, for goodness' sake. If people were smart, they'd choose to run away unharmed rather than take him on head-first. And besides, this park was known for being a fairly safe place. At any rate, he was too busy thinking to pay full attention to his dark surroundings.

The G3A3.20.

The specially adapted rifle whose bullets leave unique markings on its targets.

The gun that had been used to kill Kim Hwayoung.

The gun that Lee Sungyeol was particularly skilled at using.

Yongguk didn't know what was worse: the fact that Sungyeol was a suspect, or the fact that it even made sense  he was a suspect. He supposed it tied in somewhat nicely together. Sungyeol, as Chen had logically pointed out, had been in Yangsan on the day of the fourth victim's death. He could possibly have a connection to Park Kyung. Plus, he always acted like he was harbouring a deep, dark secret inside. What kind of secret?  The bloody one of a murderer, according to Chen.

The muscular man sighed. Spotting a nearby bench, he decided to sit down and clear his head some more before moving on. He plopped down on the cold seat before letting his eyelids close shut. Yongguk always did his best thinking with his eyes closed. He wasn't quite sure why, but he suspected it was due to the fact that his sight was blocked off. With one sense gone, his remaining four where thereby heightened, allowing his mind to focus and hone in on whatever was bothering him.

As soon as his eyes closed shut, the picture of Kim Hwayoung's mutilated corpse flashed in his head. He could clearly see the gun wound on her chest, gaping in the twisted way only G3A3.20 bullets could leave. But who could have shot it?  Well, there was Sungyeol, obviously. He was their unofficial number one suspect, after all. But as much as he tried, Yongguk just couldn't see it. He simply couldn't see Lee Sungyeol as the one behind the Mockingbird murders.

Eyes still closed, Yongguk tilted his head up. The next logical step would be to track down the owners of all registered G3A3.20s. He and Zelo had already compiled a list before leaving work. It hadn't been hard; G3A3.20s were a relatively new model, so not many were released onto the market yet. In fact, the one that the weaponry division had was probably the first one sold into public. Yongguk remembered that day fairly well. Zelo, bless his young soul, had been prancing around and asking if he could be the first one to test the gun. Chaerin had scolded him like the mother hen she secretly was, telling him to calm down before he accidentally knocked down a weapons case. And there had also been Amber, laughing good-naturedly at the whole scene, and Myungsoo as well, watching them with a smile before going back to work. And who else had been present that day? Yongguk was positive he was forgetting someone... A person who'd also tried shooting the new rifle after the three weaponry agents...

'Ah, of course.'  Yongguk finally remembered. 'How could I forget him? He had the best shot out of the four of us- hate to admit it, but it was a bulls-eye on the first load-'

Suddenly, a new thought struck his mind. Yongguk stopped short, forgetting everything else that his inner self was telling him.

"No..." Yongguk said softly, a note of shock clear in his voice, "That can't be possible..." But even as the words passed his lips, the artillery expert knew very well just how possible  it could be. His mind began racing a mile a minute on its quest for answers.

Yangsan. Kim Hwayoung. G3A3.20. Lee Sungyeol.

'It's true that Sungyeol was in Yangsan on the day of Kim Hwayoung's death.'  Yongguk frowned to himself. 'It's also true that he's got a better shot than most people with the G3A3.20. But those aren't the only conditions to fulfill as the killer. Plenty of other people do. Sungyeol just happens to have both on his back... But he might not be the only one.'

"... He's not  the only one," Yongguk concluded out loud. His normally rumbling voice was nothing more than a low whisper, too afraid to disturb the peace of the night with his startling revelation. "All along, there was somebody else. Somebody we overlooked, because it was so damn obvious  yet so unexpected at the same time-"

It was at that moment something completely unforeseen happened to the weaponry agent. He never would have admitted it, but Yongguk never saw it coming. Although in his defence, he had his eyes closed the whole while, and there hadn't been any noises in his surroundings to alert him. But still... As Yongguk was sitting on the bench, an unseen figure suddenly attacked him from behind.

It happened so quickly and without warning, Yongguk was almost taken by surprise. Keyword: almost. He didn't practice fifteen different forms of martial arts for nothing. As slim, yet strong arms grabbed him in a headlock, the weaponry agent twisted off of the bench and out of his attacker's hold. He then whirled around to confront the figure face-to-face.

"I don't know what you want from me, but I should tell you that I'm not an easy target," Yongguk warned. He couldn't quite make out his opponent's face. No street lamps were around to provide light, so Yongguk had to squint to see the person. Even then, all he could see was the assailant's frame and the outline of his dark clothes.

His attacker said nothing. He- or she- merely jumped over the bench onto Yongguk's side. Clearly he had no qualms about fighting a military-level crime scene agent.

Without wasting another second, the assailant launched himself at the CSI man. Yongguk lunged to the side, but his opponent seemed prepared for that. He matched Yongguk's speed and whipped his foot out in a Brazilian kick.

Yongguk's animalistic instincts kicked in. Raising both of his hands, he used his left hand to block his face while he shot out his right one to grab the attacker's foot. Again, his opponent seemed to predict the oncoming move. He swiftly rotated his ankle and slipped through the weaponry agent's hands like an eel.

"Huh." Tensing his muscles, Yongguk narrowed his eyes at his assailant. "If you weren't so bent on knocking me out, I'd ask you where you learned to fight like that."

Again, there was no response. All the person did was swing another well-aimed kick in his direction.

Yongguk twisted backwards to dodge. Persistent little punk. But if that's how you want to play... Crouching low, he swung his leg out to trip the attacker. It nearly worked, but at the last second, the person leapt to the side and out of harm's way. He quickly dashed towards Yongguk and shot out his fist, aiming at the exposed surface of the agent's face.

Yongguk had prepared himself for that attack, however. With inhuman speed, he grabbed hold of the assailant's wrist and yanked him forwards.

What he hadn't  prepared for, however, was the attacker pulling out of his grip and grabbing him with the other hand.

'It was a trick! A feint!'  Yongguk cursed as he realized his opponent's plan a second too late. He tried to maneuver out of the person's hold, but he didn't budge. Instead, the attacker's grip tightened. His arm pressing against Yongguk's neck became a boa constrictor, and the leg that was wrapped around his feet locked into an iron hold.

A voice suddenly spoke beside Yongguk's ear. It was a male's voice, calm and smooth, but too low to distinguish its owner. "Don't take this personally, but you were getting in the way. The Mockingbird game is just starting to get fun. I can't have you ruining things now, can I?" Right after he finished talking, a damp rag was pressed firmly under the artillery expert's nose.

To Yongguk's horror, his movements immediately became slow and sluggish. His nose filled up with the scent from the rag. It was sweet, it was cloying, it had an acidic note to it... The part of Yongguk's brain that hadn't yet been affected recognized the smell. He knew that it would be futile to fight back- useless and a waste of energy- but he still tried anyway. As he struggled to break free, growing weaker and weaker by the second, dizziness rushed to his head. It was soon followed by a foggy, lethargic feeling, one that was too overpowering to brush off with mere willpower.

It was a valiant effort, it really was. Yongguk fought against both his attacker's grip and the sleepy fog creeping into his brain, willing himself to stay awake. But eventually, after what seemed like an eternity of slow-motion struggling, Yongguk lost control of his body and surrendered to the darkness in his mind.

It was 3:41 in the morning. There wasn't a single soul awake in the park, except for the person holding onto the unconscious crime scene agent's body. Nobody had been around to witness the fight. Nobody had seen how both men had battled in the dark.

Nobody knew how the mighty Bang Yongguk had been taken out by a rag soaked in chloroform.

[A/N]  Oooh, SUSPENSE! So many new questions are coming out of this chapter! Where's Sungyeol going? What does he have to do with Park Kyung? Who attacked Yongguk? What revelation did he come to before the assailant arrived? And most importantly: Will Yongguk be okay?

I thought I could have this whole summer to update this story, but there are too many things keeping me busy ;-; Also, I'm sorry to say, but I don't think I can update for another month. I'm going to Korea to visit my family next week, so I won't be writing for a while T_____T But I hope you enjoyed this chapter! I wish you all a fun, happy, and safe rest-of-the-summer <3