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2026-01-22
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2026-05-26
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3/?
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Under The Darkest Tides

Summary:

Looking back on it years later, that was the moment. The one where Regulus understood the gravity of the tantric tragedy they had become raveled in. It was that moment on the pitch surrounded by every divine force that he realized he would sacrifice it all for his James.

One day, Regulus Black will choose freedom.

Chapter 1: September 1, 1976

Chapter Text

The smell of salt clung in the air and rested on Regulus’ porcelain skin. The sun was high in the sky showering him in heat that even the cold water of the lake couldn’t soothe. 

 

He allowed himself to sink down to the bottom, feeling water pressing down on him and his limbs grew boneless. He couldn’t see anything but felt the way the wind gently moved the water, small leaves brushing against his skin occasionally.

 

As his lungs started to tighten and his ears started ringing he kicked up and floated to the top. When he broke the surface of the lake he was met with birds flocking overhead, wind whistling through the trees, small bugs lingering on flowers. 

 

The air was clearer in the openness of the Manor in France. There wasn’t a cloud in the sky, only a light, shallow blue that seemed to twinkle whenever Regulus looked at it. 

 

Maybe it was his imagination, but Regulus liked to play pretend.

 

He could smell lemons and tea coming from inside the Manor, he was sure his mother would call him in sooner than he would like. 

 

Regulus inhaled sharply before descending once again to the bottom of the lake, keeping his eyes open this time. He felt the sting quickly and his vision blurred. The sun faded away as he fell deeper and deeper and deeper and deeperanddeeperanddeeperanddeeper-

 

“Reg! We’re almost there you’d better put your robes on,” Pandora’s soft voice flooded his brain as he blinked away the grogginess. He sat up straight, rubbed his eyes, sighed, then looked around at his friends staring at him.

 

“Didn’t know you drooled Archie, how is it we’ve been friends for five years and I never knew you drooled?” Barty asked before snickering. Regulus wiped his mouth, a scowl coming to his lips naturally. 

 

“You should be asking how we’ve been friends for that long instead,” Regulus muttered before grabbing his robes and heading to the bathroom at the back of the train.

 

The room was extremely small, barely any space to move or breathe. The air was stuffy but Regulus only needed a few minutes. After getting dressed he looked at himself in the mirror. 

 

His white dress shirt was buttoned all the way to the top and a single wrinkle couldn’t be found. His tie was tied tightly exactly around his collar, almost suffocating him.

 

Regulus cleared his throat before loosening his tie slightly, it looked rather odd so he unbuttoned the top of his shirt and moved his collar down. Barty makes this look effortless. Regulus felt like an imposter.

 

He fixed his tie and re buttoned his shirt and tried not to hear his mother’s grating voice demanding him to look pristine. 

 

The longer he looked at his face the more it felt like it was someone else’s and he had skinned them before placing the skin onto his bare bones. His eyes were sunken in, matched by bruised under eyes. His cheekbones had gotten sharper as he lost weight and grew a bit taller this summer. 

 

Regulus straightened his posture and moved his focus to his hair. His mother was always complaining about how long it was but she also thought he looked ridiculous with short hair so she left it a little longer than his ears. 

 

It was perfectly combed and out of his face. He ran his hands through it and let it frame his face so he wouldn’t look so startling. 

 

He walked past several compartments before reentering his and sitting back down. Pandora was braiding her hair, charming small butterflies into it.

 

Her hair was long and so blonde that it was almost white.  Her skin was extremely fair and got red easily, similar to her twin brother. 

 

Evan was next to Pandora, sprawled out with his feet in her lap, he had similar hair though where Pandora’s had loose waves, Evan’s was pin straight. 

 

The twins had the exact same creepy eyes, large pupils surrounded by a blue so dark it reminded Regulus of the Black Lake. Their eyes shone a deep green in the sun like the lake as well. 

 

Pandora and Evan were technically Regulus’ cousins but they were brought up in France so they hardly saw each other.

 

Barty was next to Regulus. They had met in their shared dorm first year, Barty had been ready to pass out on his bed but introduced himself first. He sounded vaguely Italian but Regulus wasn’t sure until years later when he met Barty’s mother. 

 

He remembered Barty because he had stalled the sorting hat for three minutes. Regulus couldn’t remember the exact moment they had become friends, it was something as natural as ocean tides. 

 

One day, Barty showed up in his life and Regulus is eternally grateful. He never had any friends aside from–

 

“So here’s the plan, Aleksander Greene is throwing a party later tonight, all of Slytherin will be there. I’m thinking we could put together a prank on Gryffindor and then get some first years to carry it out.” Barty plotted, Gryffindors liked to play pranks on Slytherin.

 

One of their most notable was conjuring a gigantic snake in the common room. The snake was red and gold and was so large it filled up most of the common room. Some sixth year made it a deep emerald green and shrunk it — not all the way but enough so it could rest in a corner. 

 

They had named it Salazar — unoriginal — and kept it as a pet. In retaliation, Barty somehow convinced a third year to spike four Gryffindor’s glasses at breakfast with a strong sleeping potion. 

 

The four of them spent the entire day dead asleep in the hospital wing, Regulus tried his hardest not to think about them at all. 

 

“C’mon Crouch, aren't you tired of getting children to carry out your scheming by now?” Evan asked before lighting a cigarette with his wand and opening the window. 

 

As a prefect Regulus should stop him from smoking or deduct points, but getting Evan to quit smoking is as much of a lost cause as trying to drink the Black Lake. 

 

Evan whistled and held out a finger, a brown butterfly from Pandora’s braid flew and landed on his finger. “I refuse to let those incompetent swines prank us first,” Barty motioned Evan to pass him the cigarette.

 

Evan passed it to him without breaking eye contact from the butterfly, Regulus was pretty sure that Barty didn’t even like smoking but instead liked the idea of seeming cool to Evan. 

 

“What are you going to do when one of your henchmen inevitably snitches?” Pandora asked. 

 

“Oh Pandora, uno don’t call them henchmen that’s derogatory, due they’re all too afraid of Archie to even consider snitching.”  

 

Regulus rolled his eyes, a stressed sound filled the compartment. Evan was staring directly at the butterfly which rested on his finger and watched as it squirmed uncomfortably and tried to fly away but for some reason was tethered to Evan. 

 

The butterfly looked like it was shaking and started making weird small noises of discomfort or pain. Its wings were flapping but for some reason it couldn’t escape.

 

“Evan,” Pandora hissed, Evan broke eye contact and chuckled before telling his sister to relax and let it nestle itself into Pandora’s braid again. He stole the cigarette from Barty, taking a long drag before throwing it out the window. 

 

Regulus has always been curious about the type of magic the twins possessed, Evan with his weird stunts and episodes, and Pandora’s dreams that haunted her every time she was awake. 

 

Barty was looking at Evan like he hung the moon, his brown eyes twinkling with amazement and something more before he regained his composure and cleared his throat. 

 

“So, party tonight?” Barty asked, Regulus would rather drown himself than go to that party.


Growing up loved and appreciated was something James had never thought twice about. However, when his best friend — his brother — showed up at his doorstep on a rainy July night, he knew it was something he would cherish forever. 

 

James cherished the warm hugs, the words of support, the home cooked meals, the feeling of going to sleep knowing he was loved. 

 

Sirius turning to James and making the decision to flee to his house made James feel like he had succeeded at being a good friend. 

 

It all happened fast. One minute James was helping his mother with dishes after dinner, and the next he was ushering Sirius in and sitting him down and screaming for help. Sirius had been shaking, from the cold sure but he was also scared. A feeling James had never seen on Sirius before. 

 

He had silent tears streaming down his face, muttering too quietly for James to fully make out what he was saying. 

 

His mother cast a few spells, drying him off, warming him, healing a few bones. James got him some old clothes to sleep in. 

 

They didn’t ask any questions, just made sure he was healthy and then let him sleep in the guest room closest to James’ bedroom. 

 

James remembers the next day vividly. 

 

He woke up extremely early as usual, he showered and then spent hours waiting. Waiting for Sirius to wake up and come downstairs. That moment never came. 

 

It wasn’t until three days later that Sirius finally emerged from what would become his room. Still wearing James’ old clothes, he crept downstairs and sat at the table next to James.

 

“Mum is home. Dad is at work, he’s looking forward to seeing you.” James spoke softly, cautious of his words, not wanting to make this any harder for Sirius. 

 

It had always been uncommonly difficult for Sirius to be vulnerable or show any “weak” emotions, no doubt his father’s influence. Sirius nodded slowly.

 

He inhaled sharply, “I’m sorry for just showing up–”

 

“Don’t even attempt. You know you’re always welcome here. It’s no trouble at all, you’re no trouble at all. You can stay as long as you’d like, forever hopefully.” James interrupted.

 

Sirius turned to face him, “my memory’s fuzzy. I can’t remember what I did to make her mad this time. I think I must’ve blacked out at some point, my father used a curse this time.”

 

James felt anger boiling and burying in his bones. He didn’t want to interrupt Sirius but he was so close to just going over there and cursing both of his parents. 

 

“He doesn’t usually get involved like that. My father has always been more… cold. Maman– mother is the hot tempered and impulsive one. He likes to stay calculated, always one step ahead. I’m not used to his magic, it hurts more than hers does.”

 

Sirius frowned and cleared his throat, “I spent so much time trying to escape her expectations that I ended up just like her. Bold, hot blooded.” Sirius inhaled sharply, “I remember now, she wanted me to get married.” 

 

James’ jaw dropped, Sirius was only sixteen. Noticing his shock Sirius nodded, “she hadn’t officially arranged it yet, she was just warning me and I guess I flipped out. My ma– mother was forced to marry my father when she was younger than I am. He was a lot older and her cousin.”

 

Sirius snorted, “their pureblood mania. It’s funny I ended up like her when I spent most of my childhood with my father. He wanted to teach me how to be a man and the perfect heir. My brother ended up like him in the end though.”

 

James’ shock grew but he concealed it better. They all knew Sirius had a brother, all throughout first year he couldn’t stop rambling about his “angel little brother” who was soft despite his parents wanting to toughen him up. 

 

Ever since he came to Hogwarts and was sorted into Slytherin, Sirius never speaks about him. Never. When his brother is mentioned his mood immediately sours, he never liked talking about him, seeing him, and worst of all interacting with him during school at least. 

 

To hear Sirius speak about his brother so casually was mind boggling. “I left him there. My brother has always held grudges, he’ll never forgive me. I didn’t even say goodbye, I just left. I only took my wand and a picture.”

 

James’ brows furrowed, Sirius dug around in his pocket and pulled out a wrinkled picture. James held it carefully, the first thing he noticed was how young Sirius was. He couldn’t have been older than six years old.

 

He was standing in front of a large lake with his arm slung around a boy even younger than him. They had the exact same grey eyes so James assumed it was his brother. The picture moved and showed the two of them sprinting and jumping into the lake.

 

“My cousin Andromeda took it.” Sirius snatched it back and buried it in his pocket harshly as though he was ashamed to have it. “It was one of her last summers with us before she was disowned, we always went to the Manor during summer.” Sirius sniffled quietly, “he loved swimming,” Sirius mumbled. 

 

James’ mother entered the room soon after, made both of them tea before talking to Sirius about living with them. 

 

It had been roughly two months since that day. 

 

The Hogwarts Express was moving so fast that the scenery outside blurred together. Sirius was eating some of Remus’ chocolate while Remus pretended not to notice. 

 

Peter was drifting off next to James, stroking his cat softly. 

 

 

A knock sounded on the compartment door, messy blonde hair peaking through. James opened the compartment, "Jamie you tosser! Didn't write me once this whole summer!"

 

James chuckled, "oh the outrage! It's wonderful to see you Mckinnon." They hugged tightly before she joined them.

 

"Wow okay I understand," Sirius put on his best sad face before hugging her. Once she made her rounds she sat in between James and Peter.

 

Marlene gasped, "my little cat!" She snatched the cat from Peter's arms and peppered her face with kisses. "Lily and Mary are changing into their robes, you'll see them at the feast."

 

"How was your summer Pearl?" Remus asked wiping chocolate from his lips. Remus and Marlene had grown up together in Wales, however, this summer Marlene had gone with her family to visit Ireland.

 

"It was the greatest experience! Ireland is so beautiful, oh Remus you would've loved it. We went to these cliffs, and we looked down on this beautiful spot of water. I saw Matty for this first time since last summer, guess what? He's got himself a cariad!" Marlene spoke fast, her words sometimes blending together.

 

"Shut it! Old Matthew finally found someone to put up with him?" Remus sat up. He knew Marlene better than the rest of them, including her family. Matthew was Marlene's brother who was quite older than her so they didn't see each other very often.

 

Marlene nodded enthusiastically, "her name's Claire. She's a muggle from London, he's absolutely smitten. Couldn't quit talking about her!"

 

As Marlene rambled on about her trip, James felt a sense of peace. Everything's going to be alright.


The sorting ceremony lasted an unbearably long time as usual.

 

The food was delicious and James couldn't fit enough in his mouth to stop his hunger. It seemed all four boys were going through the same thing because everyone's plate was nearly empty.

 

Marlene had joined Lily and Mary who sat close to the boys without being next to them. The candles overhead burned bright and James could tell this was going to be another good year.

 

Classes started tomorrow which was a bit of a bummer but there was bound to be a party in Gryffindor tower which everyone was looking forward to.

 

There were still some students trickling into the Great Hall, new first years were making sounds of disbelief about the castle no doubt. James let out a sigh when he finished his plate, "quidditch tryouts this weekend. You're sure your not going Padfoot?"

 

Sirius nodded and sipped pumpkin juice, "no offense Prongs but it's not worth waking up at the ass of dawn everyday. Plus now I have the freedom to quit."

 

Sirius' parents forced quidditch onto him from a young age. They wanted him engulfed in wizard activities. "I can't believe it's Frank's last year," James complained.

 

From a young age he had idolized Frank Longbottom due to his quidditch abilities. "D'you hear Alice met Mrs. Longbottom this summer? I heard she fainted cause of nerves," Peter said.

 

"Merlin, poor girl. I met Mrs. Longbottom one time and I swear the woman is mute. She didn't talk to anyone but Frank." Sirius spoke. Augusta Longbottom had raised Frank all on her own, she was extremely protective and strict when it came to him.

 

Remus chimed in and soon enough there was whole conversation about the myths they've heard of Frank's mum. James was easily distracted though.

 

By some twist of fate, James had looked over to the entrance of the Great Hall right as Regulus Black walked in. He carried himself with poise and confidence, he walked smoothly not slowing for a second.

 

Regulus was surrounded by some friends of his but it's hard to miss him.

 

James loathed him. He hated how he walked like he owned the world, as if he's never done anything wrong in his whole life. He hated how Regulus treated Sirius, letting his parents make a fool out of Sirius.

 

It wasn't right that Sirius loved his brother so much that when he came to live with James he was sick thinking about Regulus. And for what? For Regulus to just not care?

 

"Prongs? You alright?" Peter asked, James nodded and gulped some water.

 

"You guys wanna pull a prank on Slytherin tonight?"


All four of them were standing in front of the entrance to the dungeons, concealed by the invisibility cloak. They hadn't really thought this plan through so they were stuck out here until someone opened the door.

 

"Alright stick to the plan, corners only it has a bigger impact." James reiterated. This wasn't going to be their best work considering it was hastily put together, but it would still bother the Slytherins which was all that mattered.

 

"What if they're also having a party?" Peter asked, the Gryffindor party was in full swing despite the late hour.

 

"I highly doubt Slytherins party at this hour. If majority are in the common room then we'll do the dorms." Sirius planned, James knew that there had to be Slytherin parties but they had never seen one.

 

He assumed it would be a sad sight full of waltzing and fancy champagne.

 

Thankfully, a few moments later a girl stumbled out. The door was wide open and they moved fast not paying much attention.

 

Once they made it inside the first James noticed was the sound. It was unbearably loud. There was some sort of music playing, only instrumental nothing muggle like what played at Gryffindor parties.

 

James was never any good at music but he could hear at least five different instruments playing, each one adding something to the catchy rhythm filling the common room.

 

It smelled strongly of smoke, firewhiskey, and… water? James looked over and saw a huge window. He wasn't quite sure what he was looking at until what looked like a mermaid swam in front of it.

 

James flinched back, he had heard a rumor about the dungeons being under the Black Lake but he never fully believed it. Not until now at least.

 

Smoke filled the air and what looked like a regal ballroom with black leather couched was filled with people.

 

James turned and was in relief to find that he wasn't the only one in shock. Everyone's mouth was agape and their eyes were wide.

 

It's hard to believe the same Slytherins that walked these halls hexing younger students just for the fun of it, knew how to not be completely miserable.

 

"Guys, what is that?" Peter whispered, his voice shaking and then he pointed to the ceiling.

 

James followed the direction and his eyes blew open at the sight of snake. Not just any snake but a huge dark green snake that was wrapped around the top of a column. It's head was looking down at a group of maybe ten people who were standing right underneath it.

 

The snake hissed loudly and then everyone in the common room who was holding a drink took a sip.

 

"That's not the same…" Peter trailed off.

 

"I think you're right Wormy." Remus responded.

 

James swallowed, "alright stay close to the wall and head up to the dorms, ready?"

 

Everyone nodded and then they began shuffling, careful not to let their feet poke through.

 

They carefully moved around people and managed not to bump into anyone. Relief washed over all four boys once they reached the stairs.

 

"Black!" They all froze and turned around. How could someone have possibly seen Sirius?

 

"Not you Pads," Remus whispered then nodded to the other side of the room.

 

Sirius froze, his face turned a little pale when he saw him.

 

Regulus Black was leaning casually against a column with a drink in his hand talking to that Ravenclaw girl. He was sweating a little bit and it looked like he was wearing his school robes. His shirt was messy and his tie was loose. It was the most disheveled James had ever seen him.

 

A guy who must've been a seventh year walked up to him, James assumed it was the one who gave them all a heart attack.

 

Regulus turned to face him and they exchanged a few words before the other guy handed Regulus a cigarette.

 

He lit it with his wand and then continued talking to Rosier.

 

"Pads?" Remus whispered, Sirius was staring at Regulus with a haunted look on his face. James motioned for the stairs.

 

They managed to make it into an empty dorm and pulled the invisibility cloak off. "Padfoot?" James asked softly.

 

Sirius nodded frantically and snapped out of it, "I'm fine. Just wasn't really expecting to see him. Especially at a party." He muttered the last part.

 

He inhaled sharply, "well? We've got a prank to pull and we're on limited time let's go."

 

Remus pulled out the itching powder from his trousers and began sprinkling it on the beds. They moved fast staying vigilant and under the cloak.

 

They were in one of the last dorms but before they could get the powder out, the door opened.


It took Barty all of dinner to convince Regulus to come to the party.

 

He continuously said no but when they got to the common room, the party had already started.

 

So, Regulus decided to drink. A lot.

 

It was the only way he could get through such a loud event. Thanks to Aleksander Greene he had a cigarette in his mouth which mixed with the copious amount of firewhiskey he had drunken… Regulus was having a good time.

 

Pandora left a few minutes ago, claiming she need to "fly with the birds" to get back to Ravenclaw Tower. He was sitting on a couch now, pressed up against Barty.

 

He heard Salazar hiss and took a huge gulp of his drink before dropping his head onto Barty's shoulder. Evan was sitting on the armrest so Barty had his head on Evan's thigh.

 

Regulus could feel how warm Barty was.

 

"I need to go to bed," Regulus said before standing slowly, Barty nodded and grabbed Evan.

 

Regulus had lost his cloak which left him feeling a little bare in only his white shirt and tie. As they trekked up the stairs Regulus struggled to keep his eyes open.

 

He rubbed his eyes and opened his dorm door, he heard a faint clatter but didn't care enough to question it. "Archie when did Pandora leave?" Barty asked.

 

Regulus shrugged off his tie and threw it on his side table, "maybe ten minutes ago."

 

He began unbuttoning his shirt and threw it next to his bed before grabbing his pajamas.

 

"Look at what we have here," Evan said mischievously.

 

He held his hand up to the wall and picked up a small black spider.

 

Barty was laying face down on his bed and didn't look up. Regulus looked and tugged at his nape, "save it. We'll feed it to Salazar in the morning."

 

Evan smirked before throwing the spider onto Regulus' shoulder. Regulus sighed, his mother had taught him from a young age that flinching was the ultimate sign of weakness.

 

Evan chuckled before plopping down on his bed, Regulus stood in nothing but his trousers with a spider on his shoulder. Before he could decide against it he picked it up and held it in his hand.

 

Regulus sighed and covered it with his other hand before focusing as hard as he could. He could feel the spider squirming, it's legs clawing for a way out, and then it stilled.

 

He opened his hands and put the dead spider on Evan's nose.

 

Regulus changed quickly and then with a wave of his wand turned the lights off before heading to bed.

 

He was drifting towards unconsciousness when he thought he heard a door close, but he was too far deep in fatigue to care and let himself fall asleep.