After taking about forty minutes to circle the perimeter of The Reef, Katsuki swam from the shallows and its buzzing abodes down to the political and literal centre of his community, dodging away from a school of butterfly fish as he did. With the seabed here fifty metres below the surface, the water turned cool, but not freezing.

On the ocean floor, the council chambers sat in a state of reassuring dependability. Nestled in a circle of sand surrounded by red flower tree coral, boulder star coral and rocky outcrops, it was enclosed, protected. Its curving, abalone shell walls glinted with shimmering rays of sunlight from above. He twirled around one of the four auger-shaped spires on his way down, twice the length of his body, then slipped through one of the upper entrances. Inside, the chambers were grandiose, dotted with animal carvings on the sizeable columns, but largely empty. He floated down to the only significant piece of decoration: the stone table.

His parents sat at either end of the formidable table, wearing their bronze diadems in deference to their leading positions as Chief and Chief-Husband. The Captain-Turned-Head-of-Espionage, Hawks, was on one long side, with the mages, Midnight and Yaoyorozu, on the other. Even with the banquet-worthy furniture, they looked small in the midst of the wide-open room.

Midnight finished up the conversation she was having with his dad about Yaoyorozu's progression to Vice Mage. "'Bout time you showed up," his mum said, arms crossed under the manta ray robe she wore. The elegant wings draped over her shoulders and covered her form in contrast to the lack of clothing on any of the other councilmembers.

"I patrolled the border just like you told me to, old hag," he shot back, settling onto the seat next to Hawks; he was slouched in his chair with his silver tail over the armrest, leaving the wide fins on his back free to spread out. "So, what's the situation?"

On the map carved into the stone table, his dad set his finger down on a point near The Reef's border, where it was flanked by the Kelp Forest in their neighbouring tribe's territory. He answered, "A deep-sea scout was spotted here yesterday. When she was pursued, she seemed to disappear without a trace, so we suspect that they might have a secret tunnel running from here all the way into The Depths. Tokoyami was also knocked out and taken near this area." His usually gentle expression was hard now. "They're getting more brazen. It's more than just the border disputes and scuffles from the last few years; they're definitely planning something bigger."

"Seriously? How would they have carved that out under our noses without us bein' able to find it?"

Yaoyorozu stared at Midnight, who nodded to her to take the question. "Perhaps some form of reshaping or destructive magic. They could easily build and cover their tracks with that," Yaoyorozu said. "I am working on a spell to scan for hollows in case we cannot locate the entrance."

Hawks fluttered his back wing-like fins. "It won't be needed. I'm sure it won't take me long to find what the deal is."

"Oh, of course, this is just… just in case," she faltered.

"Okay, fine, but what about the big spell? As soon as we can cut off their ability to use their imbued magic, this shit and any other of their schemes won't be a problem," Katsuki pressed, leaning across the table to the mage.

Her black, flowing ponytail swished through the water as she was taken aback. "Ah, w-well, two-thirds of the necessary components are readily available. The other third, it turns out, may be… difficult to acquire."

He leaned in closer. "How difficult?"

Midnight cut in, "They're rare, land-based plants and minerals."

"Fuck."

"Well, we won't need it ready right away. It'll take me time to set the stage and draw out the inciters—I anticipate at least a couple of months," Hawks said, drawing little circles aimlessly on the map. "Tokoyami's told me everything I need to know now. I'll give a beautiful performance of my horrifying betrayal at the hands of the unforgiving, prejudiced coral reef inhabitants. Cast out from the only home I've ever known, pushed to make a new home on the abyssal plain and dying to enact my revenge."

Katsuki rolled his eyes at his dramatics. "And what if it's never ready? Any of your spy work is gonna mean fuck-all without the spell in place."

"Nonsense," he replied, a casual smile growing on his face. "Plenty of intelligence to report on, seeds of distrust to sow, not to mention subtle sabotage at a crucial moment."

His mum whacked Katsuki on the back of the head. "Yeah, you think it's all about one massive impact, you idiot? We'll win this in a war of attrition if we have to!"

He growled and clenched his hands into fists, shouting, "It's not a fucking war yet! We're gonna kill these bottom-feeders before they lay another finger on our turf and turn it into one!"

"Hey, hey, now," his dad placated, "we wouldn't even have approached Hawks if it weren't for Katsuki giving us the idea. Your strategizing has come on in leaps and breaches, son. We'll assign someone to go to the surface right away and start searching for these components, but we'll come up with alternatives, too."

Yaoyorozu nodded and placed a sandstone tablet onto the table. "Here is the list of items. We… have done our best to understand what we're dealing with, but…"

Midnight waved her hand. "Momo has done a fantastic job of researching their properties and likely locations, given our limited knowledge. With diamonds, gold and saffron, they'll be in many marketplaces; it's just a matter of expense. Not an issue. These three here," she said, pointing them out, "are regional plants and animals. Trickier. And these two…"

"…are a mystery," Yaoyorozu finished hopelessly.

Katsuki started to run through who could possibly be competent enough to be given this task. He struggled. "Moon's fucking tides. Why do these old spells even have these things?"

"We can't exactly create the trading partnerships our ancestors had overnight," his dad said.

Katsuki groaned and let his head fall on the table.

"Right, I think that about wraps up this meeting for me." He peeked up as Hawks sprung from his seat. Hawks continued, "I'm going to go for one last fly before I'm stuck 600 metres down." He saluted them, stretching out the fins that spanned from his shoulders to his waist and the pair flanking his tail. Swimming away, he flapped them with his belying strength and quickly gained speed. The resulting wave ruffled Katsuki's hair.

"Can we also be done with this now? Right now? Immediately?" Katsuki insisted.

"Don't be so impatient," his mother scolded. He flinched when she started stroking his hair, then relaxed. "But… I don't think we have anything more to discuss right now. I'll feed this back to the guards while you find someone to assign to the surface. We can reconvene then."

He shook her off and decided he would wreck a punching bag when he got home. Draw one of those fucking creeps from The Depths on it and pummel that stupid face until he was satisfied.

"Chief-Husband Bakugou, sir, may we discuss these components in a little more detail with you?" Yaoyorozu asked, holding up the tablet.

"Yes, of course. And no need for the formality," Masaru said.

"Right…" She squirmed in her chair and her lip wrinkled. "…Sir," she said and untensed.

He chuckled as Katsuki and his mother got up to leave. "See you back at home."

As Katsuki swam out of the building, the Chief going the opposite way, Kaminari looked up from the crackling electricity he was producing with his hands and leaped off the coral in excitement. "Hey, you're finally done!"

"Hah? What do you want, dunderhead?"

Kaminari's eel tail undulated as he came closer. "Dude, I was over by the west side of The Reef and there was some human dunking his head in and shouting your name! Well, actually, he was shouting 'Kacchan,'" he said, posing like a fawning lady. "That's so cute! Right, my little Kacchan?" Kaminari pinched his cheek. Katsuki yanked his hand off of him; he was rough only because Kaminari clearly didn't mind losing it.

"I will gut you, I swear."

"Yeah, course you will," he said, unperturbed as he twisted his arm so that they were holding hands. "So, why is a human asking to talk to you?"

"I don't fucking know, but I do know that I will punch you into the stars if you are in my presence for five fucking seconds longer, Denki," Katsuki warned, crushing their intertwined hands and raising them as if he were about to hit him with them.

"Well, you better get going anyway. He's probably already leaving! I'll see you later, Kacchan," he teased, slipping out of his hold effortlessly. Kaminari winked at him before he swanned off.

"I'll have you arrested for disrespecting the Chief-Son! Don't fucking test me!" he called out after him.

"Okay!" he heard from a distance.

He grumbled, sighed, then tilted his head back to the vast surface. Why in the ocean was that nerd coming back so soon? He made his way to the west side, swimming in the warm water just under the sky. He spotted the dark mass of the boat ahead of him, and, to his amusement, Izuku's face appeared in the blue.

He had his eyes scrunched up closed and he yelled out, "Kacchan! I need to talk to you!" then heaved himself out.

Katsuki thought about ignoring him, just like Izuku had done after the incident. Make him deal with the same silence and emptiness he'd found day after day on their shore. But… ugh, everyone was going to hear this weirdo shouting his stupid nickname if he did that.

With determination, he surged through the water, intending to burst out and demand to know what the trench Izuku was doing.

He broke the surface and – SLAM.

"Fuck!" he shouted, holding onto his aching forehead.

"Ow, ow, ow, ow…" Izuku winced as he leaned back into his boat. His head was wobbling so much Katsuki could practically see the metaphorical starfish spinning around him. "Why did you do that, Kacchan? Just, why?"

"Why me?! Why you! What do you think you're doing here?" he snarled. What happened to "never seeing him again"?

Seawater dripped from the ends of his green locks, staining his tunic a darker colour around his collar. Drops peppered his face on top of the freckles he hadn't grown out of. Katsuki noted he didn't have his fishing gear on the boat, just his oars. Izuku leaned on his toned arms and sighed. "I need to do something to repay you for those gems."

Katsuki raised an eyebrow. "Eh? For the cobalt?"

Izuku nodded, his face tight.

"Don't try to twist it, Deku, I wasn't asking for something in return. They were for your 'inconvenience,'" Katsuki said while air-quoting. "We're squared off now. So you can fuck off."

"I'm not twisting it!" he replied, offended. The wood of his boat creaked as he gripped it tightly. "I-I don't know if they're just like…like…trinkets to you, or something, but you don't understand what they…" Izuku stopped and swallowed. "Tell me what I can do. Please."

Annoyance rumbled in Katsuki's gut, sharp and uncomfortable, as Izuku's green eyes looked down at him. "What in the ocean do you think I need from a moronic human like you?"

Izuku glared, turned to the sky and said, "I don't know! I just—"

"Nothing. I don't want anything from you, or anything to do with you, so get back to your land and out of my sea, Deku," he warned as a vice gripped his heart. At least Izuku would know how it felt now. How dare he blame Katsuki and leave with no intention of coming back after he had just saved him? After all that time he made himself unreachable to the merman?

The muscles in Izuku's jaw stiffened. Katsuki forced himself to keep staring him down, to make him understand how much he meant it. Finally, the man relented: "Okay. I'll go."

Izuku fitted his oars into the rowlocks, got into a rowing position with practised ease, opened his mouth, closed it, then set off.

Katsuki scoffed and spent a few moments too long watching him leave before he pulled himself away. When he dove down, moved to the sandy floor and started making his way home for a date with his punching bag, he came across Yaoyorozu as she was leaving the council chambers.

"Oh! Chief-Son Bakugou!" she called to him, raising a hand.

He hesitantly slowed to a stop. "What?"

"I—sorry, is your forehead okay?"

"It's fine," he said tersely.

"R-right. Now that you've had some, um, refreshment, sir, I was wondering if…"

"Rrgh, can we not right now, Ponytail? I just got tied up talking to this stupid human and if my pretend murdering keeps getting delayed, it's gonna turn into real murdering soon e-fucking-nough."

"A human?" Yaoyorozu gasped. Her elegant, red-blue tail flickered with excitement.

"Don't get your tailfin in a twist. He's this pathetic, little shrimp who was nagging me about offering a favour before I told him to get lost."

She looked at him as if he'd transformed into a guppy. "I'm sorry, Bakugou, sir, did you just say you had a human willing to do you a favour and you passed it up? You do realise that would help solve our most pressing problem?"

"N-no—there's no way Deku of all people could—shut up!" he shouted, his face flushing.

To his surprise, the usually mild-mannered mage didn't stop, and he wondered if her inner betta was coming through as she got up into his personal space and gestured at him wildly. "No amount of research could compare to having an actual human as a guide, Bakugou! You have to tell him to help us find these spell components."

"Moon, okay, fine!" he relented, firmly pushing against her bare chest to give himself some breathing room. His tongue tripped over itself as he said, "I didn't mean to—I know that I—I-I need to catch that shrimp before he gets back to the shore."

Her dark eyes were especially steely as they bore into him. "Yes, you do."


Izuku was three-quarters of the way home when Katsuki found him. During the travel time, he had thought about their mission to the surface, how he felt about it now that he knew Izuku would be involved. And he knew what he had to do.

"Deku, hang on a second!"

Izuku's eyebrows rose and he came to a halt, seemingly more from bewilderment than anything else.

"I was just thinking, and, uh…"

He tilted his head at the merman, staying silent.

"There is… one thing you could do…"


Hope everyone is enjoying the story! Please do leave a review; they make me so happy and really encourage me to keep writing!