Yachō ni Kago / Cage for a Wild Bird

Note 1: This story is based on Shingeki no Kyojin: Levi Gaiden, Kuinaki Sentaku (Attack on Titan: Birth of Levi), the Levi-centric manga which came out recently. There will be some spoilers, so if you want to read the manga first, by all means do that. In this first chapter, this story will go past what is written and start postulating (based on an Erwin x Levi romance plot).

Note 2: Rated M for language, mild violence, and lemons in later chapters. But in case you've read my stuff before, and were expecting some smex right away, I'm afraid this story will move a bit slower, and will emulate the manga as much as possible. Anyway, enjoy!

Chapter One

Levi glared up at this blond dog of the military from where he knelt in the filth, seething with hatred. "Yeah, fuck it," he said eventually, in his most offensive, sneering drawl. "I'll join your Survey Corps."

He had said this mostly to save his friends from the threat of the blades at their necks, but partly out of an overwhelming desire to kill the man standing over him. The first one ever to catch him. Erwin Smith, he called himself. Son of a bitch.

One of his friends, Farren, managed to convince Levi not to murder that giant immediately when they got out of the lower city; he was right, logically it made more sense to use him to make some money and get out of the ghetto. But Levi knew better than to expect everything to go to plan. He would follow Farren's advice as long as it made sense, and when it didn't, he would do whatever it took to protect himself and his friends, a he always did.

But a few things happened that even he did not expect, while he was training with the Survey Corps. At first, he didn't understand how they could be so eager to throw their lives away, knowing himself how hard it was to stay alive even when titans weren't involved. But his opinion of them changed somewhat the first time he set eyes on the vast openness beyond the wall.

It was so bright. That was the first thing he noticed. He'd spent the last few years under the ground, lucky to find a few glimpses of sunlight here and there, but even above ground, he'd never realized how much light the walls and buildings blocked inside the city. The grass went on forever, no sign of human interference anywhere to be seen. The sunlight was not only bright, but warm. He had low blood pressure and tended to be cold most of the time, so the sensation of riding into the sunlight was undeniably pleasant.

Beside him, Farren and Isabela were frankly losing their shit.

"It's like somebody smeared the countryside out to cover the whole world!" Isabela cried gleefully.

"Crazy!" Farren muttered, his mouth hanging open.

Levi returned his gaze to the vast, sunlit land before them. "Yeah. It's not bad."

The first ever titan he killed, he admitted he had only been able to do because he saw how it killed the two soldiers who went in before him. He didn't consider it to be that big of an accomplishment. The three of them met up that night to discuss their plans, and Levi didn't really think about what he done that day. But then a soldier with glasses (and strangely indiscernible gender) named Hange Zoe cornered him.

"Everyone's dying to know how you do what you do. Seeing you fight brings us hope, and encourages us that defeating the titans isn't impossible." The strange soldier smiled at him. "It was really something."

He stared at the weirdo, not really having any kind of response for that. Or for the searching eyes of the rest of the team standing behind this Hange person, seemingly keen to hear his secrets, for that matter. He glanced aside bitterly, thinking about a conversation that had happened just a short time before. For some reason he didn't understand himself, he hadn't told Isabella or Farren about it yet. He assumed he would eventually, but…somehow, inside he still felt strange.

It was as his companions were searching Erwin's things. The man himself returned from his meeting earlier than expected, and Levi, on lookout, was forced to think of his feet. He cursed, knowing he would have to make conversation to keep him occupied, without making him suspicious.

The Nordic man noticed his expression and stopped. He glanced to Levi's left and right a little. "You're alone? Where are your subordinates?"

Levi scowled, refusing to look at him. "They're not my subordinates."

Erwin nodded. "I see." There was an awkward pause as Erwin stopped speaking for a moment. Levi's heartbeat started to raise, knowing he wasn't good at small talk, but he had to keep him here without arousing suspicion. Fortunately, Erwin then said, "So. How are you liking the Corps so far?"

Levi glanced skyward in thought. "It's a club for psychos and adrenaline junkies. And, of course, zealots who don't mind throwing their lives away."

"Of course," Erwin said, surprising him with his honesty. "Who else would risk their lives like this?"

Levi raised an eyebrow. "Hm. I guess that makes you chief zealot, then."

"I must tell you, it was really impressive seeing you today," Erwin said, smiling a little. Obviously he wasn't offended by Levi's comment. "I had high hopes, but I never expected you to take down an aberrant on your first day. Your teammates will feel a great sense of relief with you around, I'm sure."

Levi's mouth fell open at that, feeling an uncomfortable lurch in his stomach at the idea. Relief? Having these psychos depend on him? He could hardly admit it to himself, but he felt a sudden sense of fear at the idea. He cast a cold gaze at the ground before answering.

"I wouldn't have been able to do it if those two hadn't died before me," Levi muttered, gaze growing cold as his mind brought up images of how the titan ripped them up. "I saw the way it moved and why they died, that's the only reason I knew what to do."

Erwin's gaze seemed to grow more intense as he observed him silently for a time. "Is that so?" he asked softly. He nodded to himself. "Indeed, as you say, we are a society that is built on the sacrifices of others. Without them, we would not be able to progress."

And then Erwin said the thing that stuck with Levi for many years to come. "But just so you know, not a single one of us regrets the sacrifices we've made, and continue to make. There isn't one of us who wouldn't offer up our hearts, if it meant humanity taking the world back from them. We're that kind of society too."

Levi's eyes widened. He couldn't think of anything to say. For one of the first times in his life, he was utterly speechless. He couldn't decide for a long time after that if Erwin was really a hero, or if he was just fucking crazy.

At that moment though, Isabella appeared around the corner, skillfully hiding any signs of suspicious behavior. "Okay, Levi, done changing now," she said, adjusting her jacket. "God, you're such a prude."

"Mm. Coming," he said. He shared one last oddly significant glance with Erwin, then followed her and tried to forget it had happened.

Levi hated to admit it, but the longer he was around these people, the stranger he started to feel about what they were doing. Not so much so that he intended to drop their plans to betray and kill this man, but it did make him gradually more uncomfortable. And then, the next day, after the three of them had decided they would have no choice but to kill Erwin, the unthinkable happened.

Erwin's system of smoke rounds as advanced warning was working well at first – Levi had been very impressed the previous day. But then out of nowhere, the storm came.

None of the colored smoke was visible from more than fifty meters in the rain, and dissipated in moments. Levi felt a jolt of familiar fear as their situation looked bleak. Then, he had an idea.

"It's chaos now, the formation is broken. We won't get a better chance while we're outside the wall," he said, just loud enough that Isabela and Farren could hear him, but hopefully no one else riding near. "I think we should take him now."

Farren looked uncertain at first, and Isabela almost upset. But eventually, they exchanged a glance, their intense loyalty to Levi kicking in, and they both nodded. All at once, and ignoring the voice of their squad leader calling them, they squeezed their horses' flanks and shot off toward the front of the formation.

It was impossible to see more than a few hundred feet ahead in this weather, and they had to dodge the odd other group of soldiers, now panicking and trying to draw in their ranks. Once, a 3-meter-class titan stomped into view and picked one man right up off his horse and bit his screaming head off. Isabella went white and nearly fell off her horse, but Levi rode in front of her to block her view and keep her heading forward. They would have to go fast, before the formation was completely lost, or they would have no idea where Erwin was.

"There!" said Farren, pointing ahead and slightly to the left.

Levi followed his gaze and spotted the blond head among their superiors now racing to join with the rest of the group. Unfortunately, they were not alone. A 13-meter-class titan was hard on their tail, swinging his huge arms like pendulums, far too fast to avoid when any soldiers came close.

Levi clicked his tongue angrily. This was bad. If they killed him now, there would be no time to find the documents they needed. The best options was to drag his horse along behind them, and hope his corpse didn't fall off. If it did, or if killing him slowed them down, all these months of training, and risking their lives by leaving the wall, would have been for nothing. Was it too risky?

By some insane luck, Miké Zacharius shot into view, and sliced right through the nape of the approaching titan. Erwin even briefly stopped to grab Miké's horse for him. Now, thought Levi. Now, before the giant fell.

He kicked his horse, and drew his blade as he raced for his target. Suddenly, Erwin's head whirled around toward him, and Levi's heart pounded as Erwin drew his blade too. Levi snarled, assuming Erwin had caught on and was attempting to defend himself. But then he heard the scream.

Levi's eyes widened. He stopped his horse in its tracks and yanked it around back toward the direction he'd come from. An aberrant titan, 10-meter-class, had come out of nowhere behind them, with a big sickening grin on its face. And dangling from her cloak, which was held between the titan's index finger and thumb, Isabela was screaming.

"Damn it!" cried Farren in a panic. "What are you doing?! Cut him! What's wrong with you?!"

Levi's heart jumped into his throat. This couldn't be happening. He kicked his horse again, this time racing for the titan holding Isabela. But he knew already he was too far. Isabella thrashed in its grasp, even firing her grappling hooks at the ground, trying to get away, but she couldn't reach the giant, or anything to grab onto. The muddy earth rejected any attempt to dig into it. As Levi watched in horror, totally helpless, she looked up at him with pleading eyes as the titan reached up with its other hand and broke her back. Then it tossed her limp body into its mouth and swallowed.

Levi couldn't think. His whole head seemed to fill with rage and hate, he couldn't even comprehend what was happening. Farren was frozen in shock as the titan suddenly ran forward, stomping on his horse. The animal died instantly, and Farren was thrown some twenty feet away. He lay shivering on the ground, not even reaching for his blades as the titan's hand reached for him.

Once again, his eyes met Levi's as the giant's hand neatly picked him up, in the process crushing his internal organs, and popped him in its mouth.

Levi's body went cold. Rage turned briefly to nothingness as the shock rolled over him. So this was how the giants ate people. That was the only thought that came into his head as his horse continued barreling through the rain, headed for the monster that had just killed the only approximation he had to family.

Then, like a wave building in the water, his rage started to return. Soon that was all that was left. His humanity abandoned him as he raced toward the creature, drawing his blades in a total state of murderous nothingness.

His body on total auto-pilot, he fired his grappling hook and stuck it in the neck of the monster. The titan's grin faded as it tried to grab his wire, but Levi merely took a calming breath, then arched his arms around him, and spun at lightning speed for the titan.

He didn't care what he was slicing, he just wanted to cause it pain. His blades sliced neatly through its fingers as it tried to grab him, and subsequently through the beast's forearm as it tried to defend itself. The monster made a couple of half-hearted noises of distress, then Levi jumped onto its head. He locked himself there by firing both grappling hooks into the skull itself. His eyes widened with rage. He raised one blade high over his head, then stabbed it violently into the titan's eye.

It screamed, trying to swat him off, but he deftly dodged each attempt, and merely stabbed it again and again. Finally, he detached what was left of his blade and left it buried in that ruined eye socket, then did the same with the other eye.

The monster was rampaging around, screaming in pain and trying to swat him off, unsuccessfully. Levi merely glared down at it, and drew two fresh blades. Instead of going for the nape, though it would have been easy now, he jumped lightly down and positioned himself over the face of the creature. He raised his blade, and without thinking, sliced the creature's nose off.

Its scream increased its pitch, not that he cared. He then began carving at that face like a mad man, slashing over and over, much though none of these strikes would kill the creature. Nor, of course, would they bring his friends back. His muscles finally grew tired and he stopped for a moment to view his work.

"Levi, watch out!"

He glanced with very little interest at the speaker. It was Erwin, on his horse below. What was he yelling about?

All of a sudden, Levi realized the titan had removed one of his grappling hooks from its own head and was holding the wire in its giant fist. His eyes widened. That was not good. Normally, he may have been fast enough to slice that giant hand right off the wrist, but even if he was not physically and mentally exhausted, he knew without looking that he had no fresh blades left. He'd used them all carving up this bastard's face. He sighed, and in the moment before the monster pulled his wire, he closed his eyes in resignation.

Slice!

Levi's eyes went wide as suddenly his wire went slack. For the second time in their acquaintance, Erwin had sliced it. Levi was still heading for the giant's huge, open mouth, but at the last moment, Erwin changed direction by kicking off the stump of a hand, and tackled Levi in mid-air. Together, they tumbled to the soggy ground.

The only thing that saved their lives at that moment, as they lay briefly defenseless on the wet ground, was the fact that, though it had had time to regenerate its ruined eyes by now, Levi's blades were both still stick in those eye sockets. The titan moaned and trundled blindly around, looking for them.

Erwin got up and grabbed Levi by the collar. "Get up!" he said.

Levi was still somewhat in shock, so Erwin yanked him up by the scruff with him, whistled for his horse, mounted and then dragged Levi in front of him. "Ya!" he cried, kicking his horse's flanks.

Levi sat motionless in front of him as they rode through the pounding rain, trying to catch up with what was left of the battalion. Soldiers were riding with them here and there, but others were screaming and dying around them. Slowly, amid the madness of sound, Levi's senses started to return to him. He grabbed the wet fabric of Erwin's cloak, gripping it so hard his hand started to go numb in the cold rain.

"Put me down," he muttered darkly.

If Erwin heard, he paid him no attention, simply continued looking straight ahead and riding hard through the storm.

"Hey, you shitty bastard. Put me down," Levi growled, hitting Erwin rather hard in the chest.

Erwin paused, his expression still as stoic and unreadable as ever. "No," he said eventually.

Levi glared up at him in mild disbelief for a moment. Then rage rolled over his features. "Why not?!" he hissed.

Erwin frowned somewhat, and eventually his blue eyes flicked down to meet Levi's enraged black ones. "Because you're too valuable to the human race."

"Fuck the human race!" Levi cried, hitting him again. "Let me down right now."

"Levi," Erwin said, reaching up and cupping Levi's face in his hand, an action Levi did not understand at first. "I'm sorry. I'm sorry." Though Levi was a little too distracted to think much about it, in the midst of that storm, Erwin then leaned down and pressed his cold lips to Levi's. He parted briefly and murmured again, "I'm sorry." Then he joined their lips together once again and held Levi tight to him for a long few moments.

Levi honestly didn't care about anything at that moment, so he didn't fight hard. Soon, he was too cold, both inside and out, to bother thinking at all. So when Erwin wrapped his cloak around him and held him tighter still to protect him from the rain, he said nothing.

Commander Shardis was riding in front and shouting to get the attention of everyone who could still ride. Following him, they soon outran the storm, and made it back to the wall. They lost a third of their force in that one storm. And for Levi, his reason for living. Little did he knew, Erwin was already making plans to get that back for him.