A/N: I have a lot of stuff to do, but I was in the mood for some silliness so I added this to my fill list. God, I'm terrible at multitasking.

Disclaimer: I'm not an expert on fish or tropical reefs. I did a bit of research, but if I have something wrong, this is an alternate universe so we'll just pretend all these fish are wherever the sirens are.

Steve lounged across his favorite rock, basking in the warm rays of sunlight striking the ocean floor. From his vantage point, he watched schools of fish weaving their way through the reef.

But then the beautiful rays of light warped and the fish darted into hiding.

Glancing up, Steve saw the water churning overhead. That usually meant one thing. Another human had fallen off a boat.

Sure enough, a young man in a lightweight suit tumbled gracelessly through the water, frantically flailing his arms and legs.

Oh lord. A human that couldn't swim. It looked like it was up to Steve to save him.

Steve swam up to him with a quick flick of his powerful tail. "Shh, don't struggle," he said soothingly, pulling the panicky man into his arms. "Don't waste your air."

By now he knew humans didn't understand mer speak. He wasn't sure what the man heard, but he stopped struggling and stared at Steve with wide, entranced eyes.

Steve cupped his hands around the man's face. "I'll help you back to the surface, okay? Just stay close to me." He pressed his mouth to the man's, making sure the human's lungs were filling with the precious air he needed to survive.

When he pulled back, the man looked dazed so Steve quickly prodded him to start swimming upwards. The longer humans were underwater, the quicker they started falling apart. He needed to get the man back to the surface as quickly as possible.

Luckily, the man seemed to be getting the hint and was kicking his feet and moving his arms with Steve helping push him in the right direction.

Suddenly the man jerked out of Steve's grip, opening his mouth in a garbled scream.

Steve's eyes went wide with horror as blood started to fill the water.

No, no, no. This wasn't right. How had the human gotten injured? Steve had been so careful to steer him away from any sharp-

Steve frowned and looked down.

Clint was floating below, ripping into the human's severed left leg with his sharp teeth.

"What's wrong with you?" Steve demanded. "He was a perfectly healthy human. I could have sent him back to his people."

"Well, he's not anymore," Clint said without a trace of remorse. "Might as well finish him off now."

"No, you don't," Steve said firmly. "I'm rescuing him."

"Dude. Humans can't survive with just one leg." Clint gestured around him. "Look at all the blood. He's not going to live much longer. Not long enough to get back to his people. And if we don't eat him, the sharks will."

Steve pinched the bridge of his nose. As much as it pained him to admit it, Clint was right. "Fine," he snapped. "But next time, kill the human before you start eating him." He fixed his friend with a stern look. "We don't play with our food."

"Aye, aye, Captain."

"I'm so sorry about this," Steve said, stroking a hand over the man's cheek. "But I don't want you to suffer." He grasped the man's head in his hands and with a quick motion, snapped his neck.

"There," Steve said bitterly, swimming away from the floating corpse. "Here's your dead human. You better not waste a single bite."

"Oh, come on," Clint said as he tore off a chunk of thigh. "Humans live such short lives. He would have died soon anyway."

"You don't know that. He was young. He could have had many long years of life still."

"What are we all arguing about this time?" Bucky swam up from his favorite spot under the coral, his long, dark tail slowly flicking side to side.

"Steve got attached to this human," Clint said, gesturing to the remains of the man.

Bucky gave Steve an exasperated look. "You can't keep every human you see."

"I wasn't trying to keep him," Steve insisted. "I was trying to take him back to his kind."

"Well, I'm glad you've finally come to your senses. Humans don't make good pets. Just look at that guy you've got in the cave. He's gone fucking crazy being cooped up like that."

"He's not my pet," Steve said with a sigh. "I'm just taking care of him because he's injured."

When he had found the injured, dark-haired man a week ago, crying and clinging to a piece of driftwood, he had felt sorry for him. There was no boat in sight, no other people nearby he could direct him to. So he had taken him to a cave just off the shore where there was a small swath of land above water. Steve had been really worried about him for a day as the man just laid there on a bed of seaweed, murmuring something that sounded like stains, peppers, and show fur, which made even less sense than normal human speak. He had to be sick and delirious. But then he had started to regain his strength and pace around the cave on his injured leg, muttering to himself and scratching weird marks into the wall with a piece of charred driftwood. Crazy or not, the human was fascinating and Steve liked to watch him.

"You really can't keep him for much longer," Bucky said gently. "He's starting fires in that cave, burning all the fish you give him, and then eating them like that. That can't be healthy."

"Hell no," Clint agreed. "When he gets back to his people they'll be horrified he's eating burned food."

"I know," Steve said. "I'm releasing him back into the wild as soon as his leg's healed." The human wasn't going to be able to swim very well with a bum leg.

"Hopefully they'll take him back as damaged as he is," Clint said. "But, hey, if they throw him back into the water, I'm calling dibs. I've been craving Italian."

"Nobody is going to eat him," Steve said firmly. "Seriously, you guys. How can you think of eating such an amazing creature?"

Bucky rolled his eyes. "Stevie, honey, you think all humans are amazing."

"Exactly! You've seen the boats they make, haven't you? And the fires on the beach? They may not understand a word we say, but I can see the intelligence in their eyes. They have their own language, their own civilizations. How can we think of them as food?"

Bucky shook his head. "Because we're sirens. We've always eaten people."

"We're carnivores," Clint said patiently. "See?" He bared his teeth. "These babies are made for ripping, tearing, and shredding flesh."

"They're also good for ripping, tearing, and shredding seaweed."

Clint made a face. "How do you expect to maintain all those muscles eating that crap? You're not going to get enough protein."

Steve shrugged. "I've been doing just fine so far. If I really start falling apart I'll start eating fish, but I promise you I'm never eating another human."

Bucky gave Steve a sidelong look. "And fish aren't intelligent creatures?"

"Not as intelligent as humans. And really, I'm not going to eat any fish either if I can help it. They're beautiful creatures, meant to be admired, not eaten."

"Tell that to the sharks," Clint said under his breath.

Bucky and Clint both broke into giggles.

Steve huffed and swam off. It hurt that his friends just didn't understand. But he knew somebody who would.

He surfaced inside the little cave and looked around briefly for the human. As usual, the man was standing up against the wall, scraping his driftwood against the rock to leave little black lines and swirls. The patterns were interesting even if they didn't look like anything.

"Looking good, human," Steve said.

The man dropped his driftwood and rushed over to the water's edge with a welcoming smile.

It was a big change from when Steve had first found him. The man had been frightened and hostile, unwilling to accept any of the fish Steve offered him. But everything had changed when Steve brought him a piece of driftwood to add to the seaweed and algae nest he was making him. The human had immediately started a fire and actually started eating the fish. Within a day, he was limping around, scraping the remains of the driftwood over everything to make the weird markings. Steve was eager to encourage anything that got the human back on his feet so he tried to bring him a few pieces of driftwood every time he checked up on him.

Steve offered up the wood he had found earlier and watched as the human looked them over and separated them out into piles. Some of the wood was used for his scribbles, others were used to light the fires the human was so fond of, and there was still another pile the human had yet to touch. Steve couldn't wait to see what he was going to do with those.

The human put a hand over his stomach and rubbed, one of the few gestures Steve understood. He obligingly dove back under the water and returned with a medium-sized triggerfish.

The human beamed and selected a few of the older pieces of driftwood to start the fire.

Steve lingered, propping his chin in his hands to watch. Fire always made him nervous, but the human seemed totally at ease fanning the flames, totally at ease holding chunks of fish mere inches from the fire.

The whole time he was burning his fish, the human kept up a steady stream of chatter. He was probably explaining important aspects of human culture, telling his life story, or even just talking about the fish. But it was all just gibberish to Steve.

Steve sighed and pillowed his head on his arms. "I wish I could understand you, human."

The human glanced up, pierced a piece of fish with a thin strip of driftwood and held it out to Steve.

Steve shook his head. "I don't eat my food burned. You shouldn't either."

The human insistently offered it again.

Steve sighed. "Okay, fine." He took the driftwood spear from the human's hand and took a bite of the fish.

"Wow," he said. "This actually isn't bad." The texture was totally different than biting into a live fish and that was a little hard to get used to, but the meat was warm and actually had good flavor.

The human raised an eyebrow.

Steve smiled reassuringly. "No, it's pretty good. I take back everything I said about the burnt food."

The human beamed and patted the ground beside him.

Steve frowned. Sirens rarely left the water. Sure, most liked the occasional bask in the sun and some of the wilier sirens positioned themselves on sharp rocks so they could lure humans in with their melodious voices. But Steve's ma had always warned him his scales would dry out if he stayed out of the water too long.

The human patted the spot again.

"If you insist," Steve said. He braced his hands on the shoreline and hauled the rest of his body out of the water.

The human's eyes went wide and he hesitantly reached out a hand towards Steve's tail, eyes flicking up to Steve's face as if asking for permission.

Steve smiled and nodded encouragingly.

The human slowly traced a hand over Steve's tail, keeping up his steady stream of human's touch tickled a little, but Steve held himself still as the human's hands traveled all the way up to his dorsal fin and around to the patch of scales on his chest.

"Totally different from how you look, right?" Steve said. "And I'm sure this is really different." He guided the human's hand to his gills.

The man was momentarily speechless, a look of stunned surprise on his face.

Steve chuckled. "How else do you expect us to breathe underwater? Well, I suppose it's still a surprise for a surface-dwelling human." He pressed his hand against the human's chest. "Your kind is only meant to breathe air. Such a tragedy."

The human blinked and offered Steve another skewer of fish.

"It's okay," Steve said. "The food's for you. I can catch myself another anytime I want."

The human stuck out his bottom lip and gave Steve the most put-upon expression he had ever seen.

"Okay, fine," Steve said. "One more bite."

One bite turned into seven and before Steve knew it, he had eaten almost the entire fish. He groaned at the thought of having to catch another fish, but the human seemed ridiculously pleased.

"Look," Steve said. "I'm sure you feel indebted to me for saving your life, but you don't need to make it up to me by giving me food that I've already caught for you."

The human frowned and cocked his head to one side.

Steve sighed. "Never mind. I'll be back in a minute."

When Steve resurfaced with the second fish, he was surprised to see that the human had made several quick etchings on the floor. There was a great many of them this time, all very different designs. Some were made of intersecting straight lines, some with curves, and others with dots.

The human pointed to them proudly, one by one and then looked up at Steve expectantly.

"Very nice," Steve said. "Your designs are getting more ambitious." With the human regaining strength in his legs, his scrapings were taking up more and more room in the cave each time Steve saw them. A very promising sign for his recovery.

The human scowled and smudged his designs. He started again, carefully scraping the wood across the floor with a look of great concentration on his face. When he finished, there was a crude representation of a smiling face and a fish.

Steve's eyebrows went up. Well, this certainly argued intelligence in humans.

"Yes, the fish was very delicious," he said. He eased the wood out of the human's hand and added a body to the face, complete with fins and tail.

The human grinned widely and added a smiling human figure and a second fish.

"Absolutely," Steve said. He nudged the fish towards the human. "All yours."

While the human toasted his new fish, he chattered away excitedly. Steve was frankly a little excited, too. It was the closest he had ever come to communicating with a human.

The human quickly shoved his fish into his mouth and started more scribbles on the floor.

Some of the shapes were recognizable. There was a pretty good representation of a boat, a bonfire, trees, and human dwellings. But there were also things he didn't recognize. Weird, misshapen creatures and impossibly complicated structures. Either the drawings were bad or there was a lot more to human culture than Steve realized.

Steve started adding his own scratchings. He wasn't doing them any justice, he was sure, but he scratched out a representation of Bucky, Clint, Natasha, and Bruce.

The human added three more human figures. The third was immediately scribbled over, the human muttering darkly under his breath. Whoever this hulking figure was, he was no friend of Steve's human.

Steve gently eased the driftwood out of the human's tightly clenched hands. "It's okay," he said soothingly. "Whoever he is, he can't hurt you here."

"Stain," the human said miserably. "Foe key mar moon deed."

"Sounds rough," Steve said. He patted the human's shoulder. "But it's okay now. You stay with us as long as you need to."

Oh god, Bucky was going to kill him for this.

Steve winced. And Bucky was also going to kill him for being gone for so long.

"Well, I'm glad you enjoyed your fish," he said quickly. "I'll see you tomorrow." He dove back under the water before the human could distract him further.

As he feared, Bucky was waiting up for him, arms crossed over his chest when Steve arrived at their pod's underwater cave. "You were with that human all day again, weren't you?"

"I'm sorry," Steve said. "But we were actually communicating with each other and I just lost track of time."

Bucky squeezed his eyes shut. "For the last time, Steve, he's just a dumb animal. I know some of the things that come out of his mouth sound almost like words, but he doesn't understand what he's saying. It's all meaningless noise to him."

"He understands the general idea," Steve said stubbornly. "He was showing me human life through images and when I responded, he understood all my drawings."

"Did he really? Did he tell you he understood?"

Steve sighed. "Come on, Buck."

"No, Steve. Just listen to me for a second. You're getting way too invested in this human. The more time you spend with him, the more you convince yourself that he understands everything you say and he's actually making sense when he talks. But no matter how much time you spend with him, he'll still be a stupid human. Promise me that he's getting out of here soon. I can't stand watching you lose your mind any longer."

Steve looked away. "As soon as his leg's healed."

Bucky shook his head. "You'll be saying that for weeks, Steve. 'Oh, he's not strong enough yet. Oh, he's still limping a little.' I'm giving you a week to get him healed and sent back to his kind. If he's still here after that, I'm eating him myself."

Steve sighed. "Okay, I'll take him back to shore next week." God, he was going to miss that human. But hopefully he would be happier back with his own kind.

"Good," Bucky said. "It's getting kind of late so we might as well hunker down for the night."

"Sure," Steve said. It was always safer to be inside the cave by sunset. Too many predators prowled the waters at night. The only sirens out after nightfall were the ones up to no good.

Steve swam into the cave after Bucky. Clint was already inside for the night, sprawled out across his favorite rock, his striped purple tail stuffed inside a crevice. Steve saw a shimmer out of the corner of his eye as Natasha swam by, her sleek silvery tail catching the last of the sunlight.

"Bruce here yet?" Steve asked.

"Here," Bruce said from the corner of the cave.

"Oh, hey, Bruce." It was easy to overlook the man sometimes as his lower half blended in so well with the color of the rocks.

"Good," Bucky said. "Everybody's here. Time to turn in for the night." In a quieter voice, he added, "I want to get an early start tomorrow so we can go check out Shipwreck Cove."

"That sounds amazing," Steve said as he pulled Bucky down into their bed of kelp. "I can't wait to spend the whole day exploring with you."

"You sure about that? You don't want to spend the day with your pet human again?"

Steve frowned. "Bucky, come on. You're my best friend in the whole wide ocean. Why wouldn't I want to spend the day with you?"

Bucky shrugged. "You've been spending an awful lot of time with that guy lately. I was beginning to think you forgot about me."

Steve punched his shoulder. "Jerk. How could I ever forget about you? You're on me like a barnacle all the time."

"Would you two cut out the lovers' spats for one night?" Natasha snapped. "Some of us have a long day of hunting planned tomorrow."

Steve sighed. All those poor humans. At least Natasha tended to kill them quickly so they didn't suffer.

"Oh, don't worry," Bucky said cheerfully. "I'll keep his mouth shut."

"Knock it off, jerk," Steve said, shoving away the hand Bucky attempted to clamp over his mouth. The two of them wrestled in the darkness for a moment until Steve managed to pin Bucky down and nip his flank.

Bucky yelped. "Fuck, Steve," he whined. "That hurt."

"I'm sorry," Steve said smugly. "I thought you knew how to keep quiet."

Natasha groaned. "Why did we ever agree to live with these two idiots?"

"Safety in numbers," Bruce said.

"If any sharks show up, they'll get eaten first," Clint said.

Bucky huffed and curled his tail around himself. "Alright, fine, you assholes. We're going to sleep."

Steve patted Bucky's side. "You okay, Buck?"

"No thanks to you, punk." But Bucky reached out a hand to ruffle Steve's hair. "Night, Stevie. I'm looking forward to tomorrow."

"Me, too," Steve said fondly. "Jerk."