A/N: For this chapter, especially for the first scene, I'd recommend you listen to this: www .youtube watch?v=ubZr AmRxy_M as it is also this chapter's namesake. Enjoy!

Thirteen Years Later

The sun beat down on the beach in Shinganshina, ushering in the unofficial start of summer. The sea was once again, issuing a siren call towards any soul wandering close, calling people in with its crashing waves, salty spray, humid air, damp sand, and crying gulls.

And as always, Eren was helplessly pulled in by its spell.

He had once again left his parents' beach house at dawn with, as usual, nothing but his swim trunks and his pendant around his neck. The chord was a little faded and the gemstone a little scratched, but he still wouldn't trade it for anything in the world, and it looked just as beautiful in the dawn light now as it did then. The only differences this time were, one, he was not alone on the beach, and two, he was fairly certain his parents would not have allowed him to go windsurfing when he was nine, and they most definitely wouldn't have let him go when it was still mostly dark outside. Hell, he technically wasn't supposed to be going now either.

But it had become his and his best friend Mikasa's (who he had met shortly after entering middle school) favorite thing to do when she came with him on their vacations. So here they were, dragging their boards out at sunrise, shushing each other like a pair of children who knew they were being naughty and trying not to get caught. But they couldn't help it. The breeze was fantastic right now, and the waves were just as great. When they plunged into the surf, they only allowed themselves a moment of muffled swearing at how cold the water was, before they dragged their boards out deeper, getting ready for the waves to come. And come they did.

As soon as Eren felt that telltale kick in the breeze, he got up on his board, let out his sail, and hung onto the bar, feeling the pull in every one of his muscles as he steered against the wind. And when he really got going, he allowed himself to feel everything he had missed out on: his hair being blown back, the wind roaring in his ears, the adrenaline rush as he quite literally fought against nature, winning for a moment before the wind and water threatened to knock him over. And best of all, he got to share it with his best friend. He looked over his shoulder to see that she was a few yards away from him, close enough that he could see her thighs and biceps flexing as she fought for control with her sail, as well as her elated expression, but far enough away that they wouldn't crash into each other.

A wave bigger than the others found his board, and he found himself gripping the bar on his sail, bracing his stance so that his muscles stood out on his entire body, and hopping right through it. As the water sprayed him in the face when he landed, he couldn't help it; the endorphins that he never thought he'd feel again were flooding his body, and he laughed joyfully, feeling like he had the first time he had every tried windsurfing all over again, hearing Mikasa echoing that laughter behind him.

Reunited with the sea after being away from it for five years, he felt like he knew who he was again.

Soon enough, the sun began to rise, and the breeze began to die down as the temperature seemed to even out, marking the end of the best surfing and letting them know it was time to head inside before his parents woke up and started worrying about him, though he was sure they could guess where they were. They hauled their boards onto the beach, shaking stray droplets out of their hair. Eren's was currently sticking up in every direction, as usual, while Mikasa's short hair was held back in a tiny ponytail. The young man was still out of breath, his shoulders heaving slightly from their exertions all morning.

"Well, I'm ready to go back to bed now," he half joked.

"Oh boy are you out of shape," Mikasa pointed out, "We're going to have to do this lots more, build your endurance back up."

"Well, as much as we can before my internship starts," he pointed out. He halted for a moment, struggling with his board against the wet sand.

"Oh, that's right!" she exclaimed, helping him pull his board up the beach, as well as pulling her own, "What day does that start again?"

"Tomorrow, actually," he stated, surprising himself by how much time had passed already.

"And it's at the Sina Aquarium?"

"Yes."

"And are you going to live down there or…?"

Eren huffed a laugh. "No, it's only a forty minute drive. I can make the commute. Besides, I don't feel comfortable leaving my mom alone. I know she technically doesn't need me, but I don't know. I always worry about her. My dad isn't there as much as he used to be, you know."

"She has Fern," Mikasa reassured him.

"Yes…" Eren sighed, "I guess…I just want to be home for a while too. Reconnect with my family again after, um, after being away so long."

Their steps slowed, and then stopped in the long grass, still far away from the beach house. Mikasa let go of their boards and turned to face him, her face opening up into an expression of deep concern. She opened her mouth to say something, but Eren interrupted her before she could.

"Surfing with you was a big help," he said quickly, "I feel better already. Reconnecting with the sea and everything, feeling its power, it's comforting. Being with you, it reminded me of when we were kids. This whole place does. Only time will help, and distance. And I'm getting both."

She regarded him steadily for several long moments, as if trying to gauge whether or not he was lying to her. When she deemed that he wasn't, Mikasa asked in a low voice, "He hasn't been texting you again has he?"

Eren shook his head. "Not for a couple weeks. Hopefully he's given up finally."

"He better have," she growled, her expression darkening, "I still think you should go to court and press charges against his ass. Get a restraining order against him or something."

He exhaled heavily, looking everywhere but at her. "I know, you and my dad both. But I"-

"You want him out of your life, you're done with him ruining it, I know," Mikasa cut him off, "But Eren"-

"Mikasa. Please let it go," Eren begged her tiredly, "I've made my decision and I'm happy with it even if no one else is. Besides, if he shows up on my door he risks getting his ass handed to him by a five foot nothing deaf lady and I doubt his ego would be able to handle that."

Mikasa let out a breath, and finally relented, "Well, he better stay away if he knows what's good for him. If not your mom, then I'll chuck his balls into the asteroid belt."

Eren snorted, and nudged her shoulder with his. "I know. And see, this is why I missed you. Besides, I'm free now and that's that. Got the tattoo to prove it and everything."

"Oh yeah!" she exclaimed, her expression brightening. "Hold still, let me see it."

He laughed, and did as she asked, straightening up his back and tilting his head forward as she wandered around to his back, her grin growing when she actually got a look at the tattoo. He had snapped a picture of it soon after he had gotten it about a month ago, back when it was still red and irritated, and sent it to her, captioning it with, "Thought I'd mark a new beginning in my life by getting this. Guess I really am a free little bird now :)." It was a pair of wings that crossed at the tips, one dark and the other light. The longest bottom tips ended in elegant curls that stretched just short of Eren's ribs. A few bubbles were scattered around the wings as well, making Mikasa smile.

"Wow," she said, "This looks much better in the natural daylight versus a photo."

"Yeah," Eren grinned, "And it's pretty much done peeling now."

"I think you're right," she agreed, and then leaned in closer, narrowing her eyes as she noticed something else about the tattoo. "Hang on…oh my gosh, the shaded wing! Those are all"-

"Yeah," Eren grinned even bigger, "Pretty cool huh?"

Looking closer, Mikasa saw that the darker wing in fact was dark because each feather was filled in with the image of a different sea animal, everything from a manta ray, to a humpback whale, to a tiger shark, to a sea lion, an otter, several conch shells, a dolphin, and of course, with a mermaid right in the middle. A mermaid with dark, sharp eyes, she couldn't help but notice. All of Eren's favorite animals, she remembered, creatures that made up a large part of his identity. Creatures now etched into his skin that would follow him forever, keeping him strong and reminding him every day what he lived for.

"I like it," she said, straightening up and coming back around to his front, "You know, I've almost been thinking of getting a tattoo too. Maybe something on my ankle. I'm not sure what yet though. What do you think?"

He let Mikasa pick up both of their boards again, continuing on their way back to the beach house, his spirits lifting. For the first time in several years, the clouds of anxiety, doubt, and pain had lifted, leaving everything warm and bright again.

000

Eren was disappointed that they didn't get to stay at their beach house for the entire summer as usual, but that disappointment was quickly replaced by excitement when he remembered exactly was he getting up for at five in the morning that next day. He had told his mother that she didn't need to come back with him, that he could get himself up and out the door like a big boy and that she could stay on the beach and keep enjoying herself, but she insisted on seeing him off that morning. Said it was a mom thing, even when he rolled his eyes and shook his head fondly.

So here he was, jumping out of the shower and into a pair of khaki shorts and a dark green shirt that sported the aquarium's logo on the top of the front as well as the back, which was a whale's tail against a setting sun with "Sina Aquarium: Rescue and Rehabilitation Center" written under it in bright orange letters. After picking up his pendant from where it normally rested (on a pile of carefully arranged conch shells), clasping it and adjusting it so that the gemstone sat nicely on his collarbone, he made his way into the kitchen. Granted his stomach was filled to the brim with nerves, but he supposed he should try and force something down his throat or he was going to be sorry for it later.

He padded in quietly, and smiled when he saw Fern laying on her cushion in the corner of the room. Her ears pricked when she saw him enter, but she didn't lift her head until Eren walked over to her and scratched under her chin, wherein her stump of a tail started wagging as well.

"You'll take good care of mom while dad and I aren't here, won't you kid," he said.

She licked his wrist in answer, and he leaned over further to kiss her head, before going over to start his breakfast.

He was eternally grateful that his dad had talked his mom into getting a service dog when he was transferred to a different hospital further away. Not only was Fern invaluable to helping Carla and allowed her much more independence, but Eren knew she also enjoyed the company while her husband was working and her son had first moved away five years ago. And honestly, Eren thought Australian Shepherds were underrated as service dogs. Perhaps because they were so energetic, but Carla was an energetic person, so it matched, and she had fallen in love with the little red merle puppy at first sight.

He sat down with his breakfast, enjoying the quiet. It had been a long time since he had even remotely this peaceful, but slowly, being in his childhood home again was doing wonders to loosen the shackles of anxiety. However, the moment he took a bite of his bagel, he felt it resurge again, a voice that sounded disturbingly like his voice telling him that he shouldn't be eating this, that it was full of carbs and it was make him gain weight that. "I'm not going to be dating some fat cow. Now you're going to have to spend all morning running to burn that shit off."

His heart raced, and he almost automatically spat out the bagel. Stop it, he commanded himself, and forcefully swallowed his mouthful, though the pounding in his chest didn't cease. He could feel sweat prickling along his hairline and along his spine, but before he could spiral down anymore, he felt a cold, wet nose poking his arm. Eren looked down to see Fern gazing up at him with her huge amber eyes, and he wondered how he hadn't heard her nails clicking across the floor when she had gotten up. No, he knew. He was too busy panicking.

She nudged his arm a little, trying to get him to pet her, and he obliged, the repetitive motion doing wonders at bringing him back. He closed his eyes and concentrated on breathing, feeling the air enter and exit his lungs several times, trying not to let the fear consume him.

Eventually, it began to die away, and even the nausea that had been conditioned in him from eating anything that wasn't salad also began to fade away. He swallowed several times, and played with Fern's floppy ears. She patiently let him turn them inside out and right side out again as she waited for him to calm down.

"God, Fern," he murmured, "That bastard fucked me up really good, didn't he? Bad enough that I can't even eat a bagel without getting an anxiety attack anymore. Maybe I'll need to check myself in to see a therapist if this doesn't stop."

She started licking his wrist again, and Eren continued to pet her while he ate with the other hand, the warmth of her fur keeping him grounded, and he found himself thanking his mom mentally for getting Fern, because it looked like she wasn't just a benefit to her.

Speaking of, as soon as he finished and was grabbing his keys to head out the door, he heard his mom enter the kitchen, looking half asleep but happy that she had caught him before he left.

"Hey baby," she signed drowsily, "You nervous?"

He smirked and laughed through his nose. "Am I that easy to read?"

"Is that even a question?"

Eren shrugged. He should have seen that coming. She came over to him and offered him a hug, which he accepted gratefully, bending slightly to do so. Warmth flooded his veins, and he could feel the fear drifting further away for now. After all, the small child in him told him that there was no safer place in the world than the arms of his parents.

When Carla pulled back, she signed, "This is the start of great things for you. You'll do fine, don't worry. Just come back with good stories for me, okay?"

"Don't worry, if I get in the tank with the sharks and one bites me in the ass you'll be the first to hear about it."

She snorted, leaned up to kiss his cheek, and sent him on his way, wishing him good luck with Fern by her side as he went through the doorway.

The sun was just beginning to come up by the time Eren got in the car and started to drive to the aquarium, blasting his music as he went. Soon enough, he left the city and drove out into the more rural part of the town, the scenery that flashed by his window turning into farmland and woods.

He had officially started grad school just this past fall, and when he heard the program required an internship in order for him to graduate, he didn't waste any time and began searching around right away. He was immensely thankful that Sina Aquarium had accepted him for a few reasons. For one thing, they were the closest aquarium to where he lived. For another, they doubled as a research center and had a working lab, at least that was what the lead scientist at the center, Dr. Zoe and her assistant Dr. Berner had explained to him when they interviewed him. So he was eager to get in there. They also had, to his knowledge, many of the creatures he wanted to work with one day, namely dolphins, seals and otters.

But most importantly, they were the only aquarium to his knowledge rumored to be keeping a mermaid among their rescued animals.

That rumor, above all else, was what got Eren's blood all hot with excitement, and his childhood dream come flooding back to the forefront of his mind. If he wanted to be a front runner in the mermaid field, perhaps this would be a good place to start getting experience.

That is, if the rumor was true.

When he had told them about his interest in the mermaid field and asked tentatively in the interview if it was true whether or not they had one of the creatures at the facility, Dr. Zoe had simply smiled neutrally and said to ask her that again when and if he got the position. So one acceptance and SARRC shirt later, and it was on the top of his list of questions for today.

He pulled into the parking lot at precisely seven, two hours before the center opened to the public, and headed inside, stopping at the front desk to let them know he was here to see Dr. Zoe. Said Dr. soon appeared to greet him, wearing her white coat over the top of her green Sina Aquarium shirt and a huge smile on her face as she did so.

"Eren!" she said happily, "Welcome! You excited?"

He held back from bouncing on the balls of his feet, feeling as giddy as a small child on Christmas morning. "Oh yeah."

"Well then come back with me," she said, waving him forward.

Blowing out a nervous breath, he followed her.

Once they disappeared from the front, she began to explain, "Alright, now today, we're going to start off with a full tour of the center. I'll show you the exhibits open to the public and the ones that aren't, the lab, and everything in between. I'll explain what you'll be doing while you're here, what you'll be doing in the lab, all that good stuff. Sound good?"

"Yes, sounds great Dr. Zoe," he answered.

She slowed down, taking note of how stiff his voice and his shoulders were, and her smile became a bit wider and kinder. "Oh hon, you don't need to bother with that Dr. shit, no one else does around here. Just call me Hanji. Likewise, you can just call my assistant Moblit. Neither of us care what you call us as long as we can dissect something by the end of the day."

"O-kay," Eren said uncertainly, but his shoulders dropped a little in relief.

"So, now that we have that settled," Hanji clasped her hands together, and continued on walking, "Let's talk about your duties here. You're going to be helping the other regular workers around here in the morning to get the facility reading for opening; cleaning tanks, feeding animals, cleaning inside the center, and whatever other little things we can think of for you."

"Alright, I can do that," Eren nodded along, deciding that didn't sound too hard.

"Good," Hanji said brightly, "Then in the afternoons, when you get done, we'll have you down in the lab to observe what we do. Once you get comfortable there and get in the rhythm of things, you can start doing your own research. Now, remind me again what you said you wanted to specialize in?"

"Linguistics," he told her, "Mostly for dolphins and whales, but I want to focus on dolphins I think."

"Splendid!" she exclaimed, "That's a cool field to go into, lots to look into. As far as I know, they've only just scratched the surface with the language of dolphins, so there's a lot to discover there. And we happen to have a couple of bottlenose dolphins here at the facility that you can spend time with here."

"And, remind me what you and Moblit focus on?" Eren wondered.

"We, Moblit studies biomechanics," she said, "He looks at all animals, but he's more fascinated by marine animals. I'm more of an all-around marine biologist. All of the animals in the sea fascinate me, especially the weird ones. Angler fish, goblin sharks, giant squids, gulper eels, oh yes. The creepier and more alien it looks, the more I want to take it apart and see how it ticks."

There was an odd, almost psychotic light in her eyes as she spoke about her passion, one that Eren admired and was afraid of at the same time. She was practically drooling, and he didn't know how to reply at first, so he settled on, "That's really cool."

Hanji cackled to herself for a moment, before she swung around and declared, "Okay, here we are at the first tank!"

They padded around like that for a while, Eren quiet for most of the time as he absorbed everything around him. The Sina Aquarium was a huge, state of the art center with giant tanks full of brightly colored tropical fish, tunnels full of sharks that swam over visitors' heads, open air tanks with seals, sea lions and sea otters, and even a few colonies of different species of penguins. There was also a "touch tank" full of friendly sting rays that actually, according to Hanji were known to splash people that didn't pet them when they asked for it. It rescued animals from both the wild and marine parks, took care of them until they were healthy, and if they could, released them into the wild again. Those that didn't qualify for release lived out the rest of their days in comfort as permanent residents at the aquarium.

They had finally entered the back part of the center when Hanji began to explain, "So this is where we house all the animals that we rescue. Visitors can't come back here, and we keep it nice and quiet for the animals that are still recovering. Right now it's pretty empty back here, actually. This is where the bottlenose dolphins are being kept. We also have a couple giant groupers that we'll probably be letting go in the next month, some otters, and a few sea birds."

Eren took a deep breath. The time felt right now to ask, especially since they were away from the front of the center. "So, do you guys really have a mermaid here?"

Hanji went quiet for a moment, before she chuckled lowly to herself, and turned her head towards Eren, saying, "I was waiting for you to ask me that. The short answer is, yes, we do."

When she didn't elaborate after they took a few more steps, Eren prompted, "And the long answer?"

"The long answer I'll explain to you when we get to his tank."

At that, Eren felt a jolt in his stomach. Had he heard her right? "What, 'his'?"

"Oh yes. The mermaid we have is a merman. The only one officially recorded by science."

He couldn't help but mention, "I actually met one when I was a little kid one summer."

"Really?" she hummed thoughtfully to herself. "Interesting. Maybe the females just outnumber the mails then. Or maybe the males are just really good at hiding. Hmm…"

When she finally stopped walking, they were standing in front of a huge tank, one where the clear glass went from the floor to the ceiling, and looking up, Eren saw that it even extended past that. It looked like that half of the tank was inside the building, and the other half was exposed to the outside so that natural light could warm the water. But what really caught Eren's attention wasn't so much the tank itself, but the bright yellow "caution" signs that were posted around the glass.

"So here we are," Hanji announced, "This is our resident mermaid, Levi."

Eren blinked a couple times at the name. "Levi?"

"Yeah, we didn't choose the name. Trost Sealand, the place we rescued him from, did. Apparently it was a popular name back when they caught him. It's resurfacing again I think."

Eren barely heard her though, as he was too busy gazing into the tank, straining his eyes for a glimpse of the mermaid within. The water itself was a bit cloudy, but even so, he could see that the bottom was covered in sand and gravel, as well as a few shells, anything you'd find on the sea floor really. There were several large boulders in the back as well, but it seemed the centerpiece of the tank was a large cave, the opening of which was pitch black.

The boy spent a few more minutes scanning the tank, before he finally asked slowly, "Sooo, um, where is he? You sure he's even in there?"

Hanji snorted. "He's in there alright. I doubt you'll ever see him though. I only ever get to see him when we have to sedate him and drag him out for his checkups. He spends all day and all night hiding in that cave. Luckily there's an air pocket in there or he'd drown."

"He never comes out?" Eren asked disbelievingly, "Not even to eat?"

"Nope," Hanji said sadly, "We have to drop his food right in front of his cave. We tried to get him to come out by putting it at the other end of the tank, but he wouldn't touch it, and he almost starved himself. So that's the way it has to be."

"Oh," Eren said morosely. "I was kind of hoping I'd be able to work with him, you know? Figure out the mermaid language. I imagine it's way more complex than the dolphin language."

"Well," the doctor sighed, "We do have a hydrophone in there. And some video cameras that monitor him. But I don't think those are going to help you, as he's very quiet and like I said, he never comes out of that cave. Other than that, unless you're going to feed him, I wouldn't recommend going anywhere near that tank."

He felt apprehension rising in his chest as he asked, "Dare I ask why?"

"Yes, you should," Hanji said seriously, "Since I was going to tell you anyway. Those caution signs around the tank," she motioned to them, "are there for a very good reason. Levi, while also being the newest one here, is at the moment considered the most dangerous resident in the center. Not even the sharks have caution signs on their tanks."

"What did he do so that he needs those?" Eren felt shivers skittering across his skin as he became more engrossed.

"We don't know the full story," she told him, "But we do know that Trost Sealand purchased him from an open water pen over a decade ago, along with a few dolphins for their park, for a small fortune. He was trained to perform, not only with the dolphins, but with the three other female mermaids the park had as well. When they weren't performing, they were kept in their tanks and visitors would pay to see real life mermaids. At night, they were kept in isolation in different parts of the tank, away from each other. In fact, the way I heard it, they had to keep Levi separated from the females all the time except for during shows because they kept attacking him. Why, I have no idea.

"Apparently, doing this sort of thing day in and day out took its toll on Levi, and I understand why. You figure the same thing happens with dolphins and orcas in captivity, and Levi is more intelligent than they are too. I know there's at least three incidents during either training or shows that he snapped and killed three of his trainers, either dragging them underwater and drowning them or tearing out their throats with his teeth. He's attempted to kill several others that have gotten in his tank with him too."

Eren's eyes widened throughout her story, and he allowed himself a moment to absorb it, before he said, "And they kept doing shows with him? Even though three of their trainers were dead?"

"Yup." Hanji shook her head, "He was the park's highest source of income, so they couldn't afford not to. I'd also wager he was driven to attack them too because they were physically abusing him. He's…he's covered in scars, Eren."

The boy felt sick at that, and then that nausea transformed into righteous fury. "Well damn, if I was being abused for years and years, I'd snap and kill the people that were hurting me too."

"Right?" Hanji agreed.

"How did you guys get him out, if he was worth so much money?"

"Partially because we had a warrant to seize him on the abuse allegations, and partially because the park's owner I guess finally figured that he was becoming more of a liability than a source of profit. None of the trainers wanted to work with him anymore, so they decided that it was better to let him go. So six months ago, we went and picked him up, along with a few other animals from the park, and he's been here ever since."

"Living out his golden years in a cave," Eren said wryly.

Hanji sighed through her nose. "I know. I wish I could help him, Eren, but he's much too dangerous. If any of us set one toe in that tank, he'd shoot out of the water and drag us down."

"Because he's scared," the boy insisted, "and no wonder. He doesn't trust humans any further than he can throw them, so he views every single of them as a threat. By killing them, he's just protecting himself, eliminating the threat before it can hurt him. It's like what dolphins do when they see sharks. If we could somehow get him to trust us, show him that we don't want to hurt him here then maybe we could"-

"Eren, I know this," she interrupted him, "But unless you can think of a way to make him trust people without putting anyone at risk, there's nothing more we can do for him except to keep him comfortable and make sure no one ever hurts him again."

"Can't you release him?"

"He was very young when they captured him. I doubt he remembers how to survive in the wild anymore."

The boy bit his lip, taking a moment to calm himself, before he finally muttered, "Sorry. I just…I just wish I could help every animal in his situation, and sometimes I have outbursts like that."

"I know," Hanji said softly, "I understand. I like you, Eren. You're like me. We know who we are, you know? And we know what we want to do, and God help anyone who tries to get between us and helping all the marine animals we can, because we're going to choke that motherfucker out."

That made Eren smile a bit, and his smile only grew when she continued with, "But hey, I certainly won't discourage you from finding that way to get him out of that cave. There's a lot of experiments I'd like to do on him too. Like, I'd kill to find out how his brain works, or see what kinds of sounds he makes and for what purposes."

Eren's eyes grew wide, and he asked excitedly, "Really? You mean it?"

"Would say it if I didn't," she said sincerely. "Alright now, the tour is over. If you'd like, for now, I can take you down to the lab and let you see the files we have on Levi. And you can meet Moblit too."

"Alright," Eren agreed, and began following her as she walked away. Eren started after her, but slowed down before he got too far, sparing the seemingly empty tank one last, lingering glance, taking in the still blue water it contained. He eyed the cave particularly, before sighing, turning back around and making his way down the hall after Hanji, listening as his footstep echoed in the eerie stillness.