Note: Here is chapter 20 of Crescendo. It's getting close to a year since we started writing this, and it has been quite the journey. We'll go back to Korra in the next chapter, but for now, here's some more of Lin and Mako. Read, review, enjoy.

Republic City, Ten Years Ago

As Lin drove further into the heart of Republic City, she could feel her heartbeat increase. It was only slight, but the sensation was still enough to catch her attention. She couldn't actually be feeling anxious, could she? No, that was absurd; she was far too in control of her emotions for that to be the case.

Then again, she was hot on the trail of the biggest case in the city. The convoy of cop cars trailed behind her, sirens blazing into the midnight sky. Following her were nine senior officers, the most trained men she could gather. As the buildings around her gradually declined in quality and the citizens she passed grew to look more suspicious with each passing moment, she wondered how things had gotten to such extremes.

It had all started the report of a man being beaten to death in his own home three months ago. He was a good, honest man found dead in his bedroom, impaled through the neck with a wooden stake and covered in cuts and bruises. Despite assigning her best detectives, she couldn't seem to gather any information at all. There were no suspects, no witnesses, no motivations, and absolutely no evidence as to why a man was murdered in his home. The press eventually caught on, and Lin fed them the story, having nothing else to do with it.

From there, everything unraveled. More bodies began popping up in poor districts, badly beaten and killed with crude weapons. One man's eye had been pierced with a chopstick; another had his intestines cut open with a rusty saw blade. There were never any female victims. Most of the dead were larger, burly men who looked like they could take large amounts of punishment. The police uncovered two or three bodies every week at the height of the investigation. Yet, no one ever seemed to offer an explanation. When asked about their dead neighbors, the lower class of Republic City merely averted their eyes and walked away.

And then, about a month ago, the dead police officers showed up. The first was found hanging from a street lamp, naked and defaced. The second was found floating in Yue Bay with thin slices along his net. The third was discovered under a pier, his body being feasted on by the rats that scurried beneath the city. Every man Lin sent to investigate the situation further wound up dead within the week. It was like something out of a nightmare. She did not know how to stop something she could not see or feel.

Until, less than an hour ago, Lin Beifong received an anonymous tip over the phone from a distressed widow.

And now she was here, speeding towards the lone destination she was informed of in the depths of the city. She always suspected something darker was at play, but now she could finally confirm it. It was finally time to stop the madness that was plaguing her city, once and for all. She only hoped her backup would be enough to handle what lied ahead.

By the time she arrived at the square, she could hear the booming cheers and screams of agony. Their source stood directly before her: a massive, wooden, octagonal pavilion, several dozen meters wide on each side. In the darkness, the front entrance was lit up with torches and hanging lights, almost giving off a warm, welcoming atmosphere. If it wasn't for the screaming, Lin might have assumed that it was a theater of some kind. Instead, she knew, the true horror was kept behind the large, wooden doors, away from unworthy eyes.

Lin pulled to a stop, and on cue, the trailing cars did the same. She stepped out of her vehicle, and examined the structure intently. Lieutenant Kwo—a wise, aged officer—walked up next to her.

"So, that's Jackdaw's Den?" he pondered aloud. "Looks prettier than I thought it would be."

"Get a good look at it now, because it won't get any nicer than this," Lin said sternly. "Get some of the men to search the perimeter. There could be almost a hundred people in there. I don't want them overwhelming us."

"Gotcha," said Kwo, and he called half of the remaining officers over. "Lock down all other exits, and get two guys on the roof. No one gets in or out unless we say so." The troops nodded and rushed ahead; three snuck around the side, two launched themselves onto the roof with cables. The other four formed on Lin and Kwo, who slowly approached the main entrance.

"I can't believe something like this has been sitting right under our noses," muttered one of the cops.

"Why would someone even want to do this anyway?" asked another. "They'd have to be deranged."

"If we're lucky, you can ask the leader yourself," said Lin. As they went closer, the echoes and chants grew in volume, until it drowned out all other noise in the area, even within Lin's own mind.

"Maybe we should have brought more backup," Kwo mused. Lin shook her head.

"We can handle this. We're the best and brightest on the force. Once everyone is detained, we'll contact HQ for the pickup."

Lin pressed her hand against the wooden door, trying to feel the vibrations coming from inside. Even without being able to use her earthbending, she could feel the entire building trembling with excitement.

"Don't make any moves until you get the signal, got it?" Beifong instructed. "Don't break formation. If one person panics, we'll all go down. Is everyone in position?"

Her men gave her nods in agreement. The radio on her belt sizzled, and the other officers waiting around the building gave their approval. Lin took a deep breath, and raised her fist.

"Okay, on me. One… two—"

"Wait, are you just going to break the door down?" Kwo suddenly asked. "Isn't that a bit much? Couldn't we at least knock first?"

Lin cocked her head to the side, her face going blank. She shrugged, and lightly rapped on the door.

"Police. Open up," she said in a dull, unenthusiastic drone. Not even Kwo could fully hear her over the roar of the crowd. She sneered. "Well, that was worth a shot. Now, it's my turn…"

Without wasting a moment, Lin picked up her foot, and with one swift motion, kicked down the massive wooden doors, sending them flying into the building. As she stepped inside, the noise came to an abrupt stop. It was now clear for her to see what was causing the commotion. The entire ground floor had been stripped of furniture and covered in a thin layer of dark gravel. There was a long cord of rope laid along the floor to form a circle, roughly twenty square meters in area. Stairs were immediately to Lin's left, leading up to a balcony that wrapped around the circumference of the building. Torches hung from every corner, illuminating the crude ring in a soft, orange glow. Most notably, the entire balcony was full of drunken, violent people, who clanked drinks and cheered at the carnage below. Within the circle itself, two bloodied, shirtless men were grappling with each other over possession of a crowbar; a dozen other weapons were thrown around them, most of them already drenched in blood.

The two men stopped their fighting the instant the Chief entered, followed by her support team. The crowd went silent. Lin scanned the faces in the crowd. She counted nearly fifty men crammed together on the balcony, all struggling for a decent view. She scoffed.

"So, this is how people manage to entertain themselves these days," Lin muttered under her breath. She spoke up. "Who's in charge here?"

She received no response. Most of the barbarians merely exchanged glances with one another, unable to determine if the officers were real or part of a drunken hallucination.

"I'll ask again," Lin threatened, "who is the boss here? We'd like a word with him."

"I'm the boss!" called a deep voice from above. A figure pushed its way to the front of the balcony, and leapt over the railing and down into the arena. As he landed, the crowd hollered. He matched Lin's height, but was decidedly thicker, teeming with muscle mass. His face was heavily scarred, dark marks streaking down his nose and chin. His right eye was glossed over, and when he smiled, half of his teeth were missing or broken. Dark dreadlocks flowed down his back, and an equally long beard ran over his chest. His clothes were filthy, and Lin detected a horrid musk emitting from his person, as if he had bathed in mud minutes before.

The man walked straight up to Beifong, and smirked. "Welcome to Jackdaw's Den," he boasted. "Usually, all spectators and participants must pay a small entrance fee, but we can make an exception for you, Chief."

"You're the guy who runs this place?" Lin asked, unmoving.

"Yep," he admitted proudly. "Name's Jackdaw, and these… these are my boys over here." He motioned to the audience, who let out a collective cheer and laugh at their leader's actions. Lin remained unimpressed, but the big man continued. "Now, we weren't expecting any visitors tonight. It seems like someone must have snitched about us. That's against the rules. We'll have to pay that traitor a visit later."

"We're putting a stop to this," Lin stated confidently. "These little street fights of yours are over. I'm giving you one chance to come with us peacefully. Don't test your luck."

"Hmm," Jackdaw stroked his beard mockingly. "You make a strong argument, Chief. But the thing is: We like doing this. Jackdaw's Den is a vital part of our lives. We aren't just going to give it up. Right, boys?"

The crowd erupted into chorus of cheers. Jackdaw leaned in so that his rotten face was inches away from Lin's. Her scowl deepened as his smirk grew.

"This is your last warning," stated Lin once more. "You have made my life very difficult these past few months, and because of you, a lot of people ended up dead. So, either come with us quietly, or I'll make you come."

Jackdaw backed off, and turned away from the officers. He stroked his beard.

"Now, that's an interesting proposal," he pondered. "I have a better one… it involves you head hanging from my wall!" Without warning, Jackdaw snatched a nearby sword from the ground, and swung forcefully at Lin's neck. She was only barely able to duck in time, the sharp metal passing centimeters over her head. She lurched forward on instinct, planted her foot firmly in the ground, and landed a powerful uppercut to Jackdaw's chin, knocking the tyrant out cold. As his massive body hit the gravel with a thud, and the audience looked on in shock, Lin turned back to her comrades, and gave the order.

"Now!"

All at once, the ceiling burst open, and Lin's squad flooded the building from all angles. Cables were launched in every direction, locking on to any person they could find. Most of the criminals tried to flee, trampling each other to get to the stairs or throwing themselves off of the balcony. They swarmed, but the officers never gave up ground. Anyone who got close was tackled and cuffed; the rest were taken down from afar with cords wrapped tightly around their limbs.

A few tried to attack Lin. One picked up a shovel and took wild swings at her. The metal tool slammed against his skull with a flick of her wrist. Another tried to sweep her legs, only to get a boot in the throat. They kept coming at her, and she continuously knocked them down. She lost count of how many bones she broke, how many teeth she punched out, and how many concussions she caused. Yet, in the mayhem, she was able to watch her team at work, and it brought a sadistic form of joy to her heart. The other nine were fighting with machine-like efficiency. Not a single crook managed to get past them without being broken in some form or another. She knew she was working with the best. To them, fifty men were nothing at all.

With one final thud, everything went quiet. It wasn't until the adrenaline subsided that Lin made out the sheer number of bodies lying around her. The legendary Jackdaw's Den had been reduced to nothing in minutes. Blood and tissue coated the gravel beneath her feet.

"Kwo, we're going to need some help cleaning this place up," Lin called to her companion. Kwo nodded and stepped aside to call reinforcements. Lin took a deep breath. She would sleep well that night, knowing of all the work that she did.

But then, from off to the side, came a deep chuckle. "Oh boy… I told him these boys were a bunch of idiots."

Lin ground her teeth, and approached the large, hairy body from which the voice came. Jackdaw chuckled again. "Can't believe he wanted to start a rebellion with these losers. What a jackass."

"What the hell are you talking about? Who wanted to start a rebellion?" asked Lin.

"J…Jackdaw," the boss stuttered, blood bubbling from his lips.

Lin growled. "Jackdaw? You said you were—"

"Oh no… I aint anywhere close to being the big guy. He couldn't be here tonight. Said he had to take care of some misbehaving 'associates'. Shame, I think he would have enjoyed the chaos."

"Who is the guy who actually ran this place? What was his real name?"

"Real names aren't important to him," said the faux leader. "But… but once he figures out that you've ruined the Den, he'll carve your intestines out and feed them to you."

"Do you know where he is?" Lin asked. The large man shook his head.

"I aint telling you shit," he sneered. Immediately, a rough, metal boot shot into his stomach, and forced the air out of his lungs.

"Unless you want me to start breaking fingers next, I suggest you tell me what I want to know," Lin threatened.

"His… his name is Domin. Domin Kuzarov," he choked out, his tough façade fading under the immense pressure. "He lives on the end of Turtle Row, in the ashen wood house. He keeps the door unlocked; he knows that no one would ever try to steal anything from him without consequence."

"Well then, I guess we won't have to be too forceful with the man," Lin muttered. She removed her boot from the defector's belly, and spoke to her troop. "Listen up. Once we get this on lockdown, we're moving out to Turtle Row. It's time we put the man responsible for everything where he belongs.

"You really want to go after Jackdaw? Good luck!" wheezed the bleeding man. "Word of advice, Chief. You don't know what you're getting into. Jackdaw aint just like any other criminal out there."

"Save it for your lawyer," Lin sneered, and stormed out of Jackdaw's Den. She heard the sound of sirens blaring in the distance. The night was still young, and there was still one more monster left to catch: the one who started it all. She was ready to put this nightmare of a case behind her. By the time the backup arrived, she was already in her car speeding towards Turtle Row.

"So that's Jackdaw's Den," said Mako, satisfied. He leaned against the white hospital wall as Lin nodded her head.

"Fun, isn't it?" she joked. "Every weekend, they crammed as many people as they possibly could into that building to watch them beat the living crap out of each other. They were gathering good soldiers for a rebellion against the government, using the fights as some sort of screwed up training ritual. Apparently it got so bad that they started calling the entire surrounding area the same thing. A lot of people died back then."

"And this 'Jackdaw' guy, Kuzarov… he was the cause of it?"

"Yeah, he was the one who came up with the idea. Survival of the fittest mutated into its deadliest form. He was the reigning king of the battles. Every time someone seemed to rise through the ranks too quickly, he beat them into submission. It turns out that building an army was only secondary to stoking his own ego. The weirdest part: He was only a kid when he started it."

"A kid?"

"Well, nineteen," Lin corrected herself. "But he was young, brash and dangerous; the worst qualities you want someone to have on the wrong side of the law. That's why we went after him as soon as possible. We tried to bring him in without anyone else getting hurt."

"Let me guess… you never found him."

Lin sighed. "No, we found him alright. He was exactly where they said he would be. The ten of us stormed his house at one in the morning. The entire house was dark and made of thick, white wood, and the halls were so tight that we had to move in single file to reach him. We stumbled around in the darkness until we saw a red light coming from the underside of a door leading to a back room. I remember peering inside and having this terrible smell hit me. Jackdaw was there, standing over a guy chained to the wall. The man was missing his left foot; the wound was still fresh. A knife was being waved in front of his face.

"I gave the order, and three of us charged in, the others holding back. But, he didn't look surprised to see us at all. He grinned, proudly showing his work like it was some damn fine art piece. I told him everything that happened, everything we were planning on doing with him, and he wasn't fazed in the slightest. He just said, 'I'm impressed. I thought it would take you longer.' I had one of the officers go to cuff him."

Lin suddenly looked away, a pained expression taking hold. She spoke quietly. "I've never seen anyone move so fast. In the blink of an eye, there was a blade jammed into his throat, and the next thing I knew, the whole room was on fire. We had been led straight into a trap. He was a firebender, and it only took a few seconds for the flames to spread to surround us. The halls were too narrow to use our cables or gang up on him, and the foundation was too thick to dig up fresh earth to defend ourselves. I saw him charge headfirst at the others, and he carved straight through them. These were the most experienced officers on the force, and he tossed them aside like broken toys. The way he moved and fought… it was inhuman."

Lin turned back towards Mako, stricken with pain. "Ten of us walked into that building, Mako. I'm the only one who walked out. Well, me and him. I managed to drag him out by the hair before I collapsed of blood loss. I was stabbed straight through the kidney—still have the scar to show for it. I watched a lot of good men die that day. And that monster… he got away with everything."

"I thought you said you dragged him out of that building?" Mako asked sensitively. It was unsettling to see the Chief so shaken up about something. She had seen so much that it was easy to think she had gone numb to everything. "Do you mean he escaped?"

"Worse," Lin admitted. "We let him go."

Mako froze. "You let him go? He killed nine senior officers!"

"And almost killed a tenth," Lin corrected. "And, he tried to lead an armed revolt, and had been killing people left and right for weeks in the Den. He deserved life behind bars in a maximum security prison, without question. But, then he told us who he was working for, and what he was doing for them. And once that was out in the open, we managed to strike a deal."

"What would you have gotten that would justify letting someone like that go, exactly?" Mako asked inquisitively.

"Easy," stated Lin. "He was the one who gave us intel to bring down the Black Alchemists."

Mako raised an eyebrow. "The black who?"

"You never heard of the Black Alchemists?" Lin said in surprise. So much for a dramatic reveal, she thought. "I figured you would have heard about at least one of their attacks."

"Attacks? So they were a terror group?"

"More like a cult," Lin corrected. "No one really knew where they came from. Some said they were a subsidiary of the Red Lotus. Some believed they were created a thousand years ago as a pact between spirits and humans. Others think they were just a bunch of wealthy kids with too much time on their hands. Whatever they are—or were—they caused mayhem wherever they went. For decades, they committed radical acts of violence throughout the world, most of which without any reason whatsoever. They always managed to stay under the radar, even from world leaders. If the Red Lotus acted like a cannon, the Black Alchemists were like parasites feeding off of their hosts slowly and quietly. Nobody knew what they were after, nobody knew where they would strike next, and nobody had a clue how to stop them."

"Except Jackdaw," Mako said bluntly.

"He sold them out once he realized that all of his work was going to be undone. It finally got through his head that he wasn't playing a game, and he confessed everything. It turns out, Domin was one of the 'Dragonblooded', as he put it. To the tomes of the Alchemists, the six 'Dragonblooded' are the most fearsome warriors in the world, and act as the leaders of the organization. Jackdaw and the other five were planning a massive, coordinated attack on Republic City, using his army of burnouts to lead the charge. He agreed to hand us over the names of the other five heads of the Alchemists, in exchange for a heavily reduced service time."

"And you gave it to him."

"He got three years and five hundred hours of community service," Lin said sadly. "The information he gave us was legitimate, and within the week, the Black Alchemists were completely disbanded, never to be heard from again. I tried to screw him out of the deal. I saw what he did to my men. But, a deal is a deal… especially when you hire a damn good lawyer to help you out. After he was released from prison, he was placed under house arrest, where he remains to this day, under heavy monitoring."

Mako stroked his chin. "If Kuzarov is still in the city, it's likely that he's the one leading Jackdaw's Den. And if those two are connected, then that means there's a chance that he's also the Hanzi Killer too."

"Hmm," Lin groaned. "It just doesn't seem right. Jackdaw has been docile for the past five years. The Alchemists are dead and gone."

"You said it yourself that Jackdaw was good with knives, right? And he would have a motivation for trying to kill you. Plus, we know he's doing something illegal because we know Jackdaw's Den is functional again. The evidence is right there in front of us. Why can't you just accept that?"

"Because with Jackdaw, nothing is ever that straight forward," Lin said sternly. "We don't have any direct proof that links him with the recent killings, and he already have two strong leads that haven't been thoroughly checked out yet. Now is not the time to start another manhunt."

"But—"

"No buts. This is an issue we'll have to deal with separately. Off the record from the rest of the investigation." Lin thought for a long moment, and then said, "I want you to head back to the station and talk to the Deputy Chief about brining Jackdaw in for an investigation. If you really think he has something to hide, we'll get it out of him. But in the meantime, stay on your task. Search for the Killer. Find the Tinkerer. Jackdaw can wait."

"Yes, ma'am," Mako said with a salute. He faltered. Something did not sit right with him about Lin's story. He went to leave, when Lin called him.

"One last thing detective," she stated. "Don't tell anybody else about this. Don't mention the Black Alchemists. Don't mention the Den. Don't mention Jackdaw. Got it?"

"Don't worry, Chief," Mako said with certainty, "I won't tell a living soul."

"A cult!?" Sy yelled furiously. She grabbed on to the edges of the table, the force of her grip causing the wood to buckle. Mako rested his head in his palm. The other ten occupants in the coffee shop were staring at his girlfriend with blank expressions, unsure what to think of the screaming albino teenager. Yet, Sy barely reacted to the stares, instead shoving a finger directly into Mako's monotone face.

"Pardon my language," she continued, "but what the cocoa beans are you doing getting involved with a cult?"

"I'm not involved with a cult," explained Mako. "I'm investigating a former cultist. There's a—wait, how is 'cocoa beans' supposed to be bad language?"

"Duh! I'm not actually going to curse in public, Mako. There are children around. I have sensibilities, you prick!"

"Just please stop shouting," Mako begged. "I'm not even supposed to be telling you this in the first place, so please calm down."

"How am I supposed to calm down when you tell me something like that?" Sy asked in disbelief. "That's the worst thing you could possibly tell someone. 'Oh hey, Sy. I just want to let you know that a bunch of crazy guys in robes are going trying to capture me and cut me into ribbons on a sacrificial alter. No big deal.'"

"It's not like that at all. There isn't any giant conspiracy theory going on. There's a criminal who used to be a part of a long-dead cult, and now I have reason to believe that he could be involved with the Hanzi Killer. Besides, why is this freaking you out? It's no more worse than it was when I investigating before."

"What are you talking about? It's indefinitely worse," stated Sy. "Serial killers are just psychos who usually only attack a specific group of people due to some messed up mental health issue. Cults not only have a bunch more members and choose have a lot more variety when it comes to killing people, but when someone tries to interfere with them, they like to send messages, usually in the form of dead girlfriends!"

"And here I was thinking that you were concerned about my safety."

Sy groaned, and threw her head back. "Of course, I care about your safety. But it's your job to go after the bad guys, so you constantly throw yourself into danger. I—on the other hand—am a delicate, little flower. I want to stay as far away from illegal activities as possible. If you get in too deep with the wrong people, then we're both screwed."

"I think you might be overreacting to this. Nothing is going to happen to you or me. The Alchemists have been dead for a decade. And we are only bringing in this 'Jackdaw' guy for an interrogation, with plenty of highly-trained officers keeping watch on him. Lin even said that he went docile, so there's nothing to worry about. Everything is going to be fine."

Sy rolled her eyes. "If you say so, detective." She uttered the last word with just the smallest bit of contempt buried inside. She then grabbed her remaining half-cup of coffee, and downed the entire mixture in one large gulp. She slammed the empty foam cup on the table, and wiped the remaining brown drops of deliciousness from her lips. Mako watched her inquisitively.

"Uh… why did you just do that?" he asked.

"I felt like it," she grunted, folding her arms over her chest and glancing off to the side.

"Isn't that still really hot?"

"So what if it is?"

"Doesn't that cause you pain?"

"Bitch, I am the pain."

Mako scratched his chin. He did not have the greatest understanding of women to begin with, but with Sy, it seemed like that problem was amplified. Sy was—after all—like no one else, and that made getting to know her a troublesome affair at times. He did not understand why she seemed so on edge on something that in no way related to her. She still remained completely isolated from the rest of the case. There was absolutely nothing that could harm her, so it seemed illogical to him that she would be in such a terrible mood over his decisions.

But then, to screw things up even further, Sy stood up, walked around the edge of the table, and pulled Mako in for a tight kiss. Her warm lips interlocked with his for but a few moments, and he felt their tenderness as she breathed softly into him. She tasted distinctly like a blend of coffee and something unidentifiably sweet—a flavor that, like its owner, was unique in every way. She pulled away as suddenly as she started, and looked into Mako's eyes with an expression he could only describe as some sort of melancholy.

"Just watch yourself out there, moron," she said coldly, "and try not to get in over your head."

Sy sauntered out of the coffee shop, multiple pairs of eyes following her as she left. Mako looked down at his own, barely-drunken cup of coffee, and took a deep breath. He really did not understand women at all.