Disclaimer: I own nothing

Required info found at the bottom of the story

Huge thank you to my Betas, Miss Horigan, Amelia, and Shini.

Regulus' eyes swam in his delirium. The coarse walls that surrounded him blurred, the rough edges of the rocks once illuminated by the light of his wand now shapeless. Black. The waterline indecipherable and the shore he had come from lost.

The difference between the present and the past was intangible and he fell inside memories from years before. Memories of when the walls of his childhood home trembled with screams, his mother's words lost inside a silencing spell that was meant to keep him unaware. A spell that locked away the voices of his parents, the slurs they spit at one another. A spell that did nothing to hide the wall that shook beneath the force of which his father had shoved her into it or the broken glass that could never be cleaned up completely, the shards always tucking themselves away in a hidden corner.

Memories where he did nothing to stop it. Where Sirius left him alone.

"Fuck, Sirius. You can't just leave." Regulus gaped at him, at the sadness held in his brother's face and the facade he built to try and hide it. Sadness that Regulus didn't give a shit about.

"I have to." He said the words with resignation, his voice forceful and unsympathetic as if this choice had been thrust upon him and not that he had taken it.

And Regulus knew that he would have left, too, if he had the chance, he wouldn't stay here. Not in a place with bruises and broken bones. With magic capable of healing them, of making them seem like they hadn't mattered at all. But, that was not a chance that would be offered to him.

He wondered how much of this opposition, this desire to leave and never come back was out of rebellion and how much Sirius actually carried in his heart.

"You have to? Or are you doing it because perfect James fucking Potter asked you to?" The words slipped from Regulus like knives, flung towards Sirius in a way Regulus was sure would wound him. "There is no light and dark side of this war, Sirius. We're all the same fucking shade of gray."

The rocks were hard beneath him, his body draped limply across them. Regulus didn't know when he had fallen. He saw flickers of gray hanging above him, suspended in memory, saw the movement of Sirius' lips and heard the broken sound of his voice telling Regulus he would never be enough. They ricocheted around the cavern, cutting across Regulus and though they were words Sirius would never say, they hurt him just the same.

"Gryffindor! Where dwell the brave at heart." Sirius' voice wavered with pride, his fists pressed into his hips and his chest puffed outward.

"They'll be disappointed in the git they got, then. First mistake the hat made, I think." Regulus' words were punctuated by his own laughter. Laughter that was cut short as he watched his brother deflate, though the change in him was nearly unnoticeable.

"Yeah, they'll never take you anyway." Sirius flopped backward on his four-poster bed, his eyes locked on the canopy above him.

"I wouldn't want to be with you anyway," Regulus retorted with an exaggerated wrinkle of his nose. "The stench of your superiority would make me sick."

"You'll fit right in with the other snakes," Sirius sneered, looking Regulus up and down. "Slimy, shrewd little Slytherins. Great way to carry on the family tradition."

"Sirius…" His brother's name fell from him in a lazy rasp, his body feeble. Regulus curled in on himself.

He just wanted the warmth of the brother he had known, the brother that had loved him.

"It hurts," Regulus hiccuped, stifling a broken sob. He could feel the snot that dripped from his nose although his tears had already begun to dry.

He hugged his arm close to his body, trying not to think of how it had looked, the bones beneath displaced. With a yelp of pain and the mumble of a spell it had been fixed, the broken bone melting back into one. The pain no longer radiated through his now healed arm, but that wasn't why he sobbed.

"I know," Sirius said from somewhere close beside him. His voice was full of things Regulus was too young to understand.

"I know," Sirius said again. He pulled Regulus close, the years and the distance between them suddenly erased. "He's hurt me before too."

Regulus cried all the things he could not say, the tears that had dried now spilling from him again. He didn't understand the rough grip his father had had on his arm or the sting his father's palm had left across his face. He didn't understand it, and that was the most agonizing thing of all.

"But, just think…" Sirius pulled away, a smile in his voice, his thoughts having drifted far from Grimmuald place. "... In a few more years we'll both be at Hogwarts. We'll be away… where no one can hurt us."

He wondered when all of it had gone so wrong. If he had been destined for this place at birth, his parent's ideals flowing through his blood, mapping parts of his brain he wasn't sure how to change, or if it was one of a million other decisions he had made. If it was when the Sorting Hat had shouted his name among the snakes and they had clapped victoriously, if it was the people inside Slytherin that had led him astray — people like him who were born into darkness and raised in the shadows of their wrongdoings, sickness, prejudice. Which one of those things had led him to the Dark Lord? Led him to this cave where he felt the fight for life slipping away, the desire to lay here forever consuming him?

Why had he not fought harder? Why had he simply accepted the things he had been told? He hadn't been brave, or chivalrous; he hadn't stood against the things he had been taught, he'd instead allowed himself to be swallowed, the serpent of Slytherin devouring him, spitting him out broken and disfigured, sure he'd never be whole again. It was no wonder why Gryffindor had taken Sirius and why it hadn't taken him.

Sirius sneered at him across the Great Hall as Regulus left, standing proudly as he walked from the sorting stool to his house table. He allowed himself only a quick glance at his brother, anything more than that hurt. They'd been so close once, back before house camaraderie tainted the things between them.

His own lip lifted in a grumble, shot back towards Sirius where he found defeat, disappointment reflected at him in return. Regulus swallowed any pride he had carried with him, pride that was instead replaced with the fear that this was the end between them, that whatever love Sirius had brought home for him the summer before would never be the same again.

Regulus blinked away the memories, the years of hate — love — dying away just enough that clarity could replace it. He reached out, gripping his wand which had fallen to his side. He cast another Lumos, the one that had brought him here, on the boat, across the water, and through each swallow of potion had snuffed in time.

The reignited light glimmered across the black water of a forgotten sea and Regulus shifted. His mind still swirled, his vision fuzzy, and he thought he may be sick. His tongue felt like sandpaper as he dragged it across his lips. Sandpaper in the Sahara. He was so very thirsty.

He rolled onto his stomach in a feeble attempt to crawl, to edge himself to the only water in sight. He moved across the ground centimeter by agonizing centimeter. The stones were jagged beneath him as he pulled himself. The sharp edges pulled at the fabric of his robes, tearing through and across his skin. His body was numb, impervious to the blood that trickled from him. Regulus couldn't tear himself away from the edge of the stony shore, the water that glistened across the white stones that gleamed beneath the light of his wand.

It was murky, the depths of it lost beneath the shadows of the cave. He trembled, his arm moving upwards, his hand hovering above the black water. His eyes scanned the surface, searching for the movement of fish, for anything that could lay beneath. He saw nothing.

Regulus dipped his fingers, wetting the tips. He brought his hand back to his face, letting one, two drops fall, splashing back where it had come. He brought them to his lips then, sucking the water from his skin, letting the salt that was somehow still so satisfying dance across his tongue.

He felt the effects of the potion dim, the rawness of his throat begin to ease, and the memories that had tortured him begin to return to dark places even he had trouble finding.

He dropped his wand, letting it clatter against the rocks before his hand met the water's edge again, breaking the surface and allowing the dark water to fill his palm. There was a splash of water, a shadow moving just in his peripheral vision. Regulus moved backward, his hand fumbling for his discarded wand as another movement came and something clammy clutched his wrist.

In the diminishing light of his far away wand, he finally saw it, saw the decayed flesh that had pulled away from bone, the grey of it hanging, sagging from what had once been a hand.

Regulus recoiled, trying to wrench himself from the grip that only seemed to tighten. His lungs froze inside him, his heartbeat thundering against his ribs as he tried desperately to scurry away from whatever the fuck had grabbed him. The hand holding onto him pulled and a body followed, lumbering from the water, crawling inhumanly towards him. The body was withered, shrunken and wrinkled by the water that had hidden it. There was decomposition throughout, patches of flesh that were missing entirely, though no blood spilled from these wounds. The thing that stalked after him was not alive, instead, reanimated by a dark magic Regulus had never known.

The creature smiled, the space that should have held lips lifting to reveal yellow, jagged teeth. The dark shadows of its eyes shone with a thirst Regulus had never known, one that dwarfed even his own from moments before. He wanted nothing more but to run.

His hand landed, finally, on the wand that he had so carelessly dropped. He gripped it now, the tip held outward, trembling as he thought of nothing. Every spell that he had known was now wiped from his mind, forgotten. For a moment he thought of Kreacher, wondering if the house-elf had known this was here though a part of him knew that the elf had no idea. He thought, then, of the corpse that crawled towards him, the second, the third following after.

The features of their faces blurred together, the rotting flesh seeming to repair itself before his eyes, his memories painting the features before him with a sight he had known before. The grey became shades of brown, from the lightest of light to the darkest of dark. The scalps before him that held only colorless strands morphed before him, too. The dead eyes filled with color, lips with a blush, and he understood.

His wand dropped in hesitation, the knowledge that the inferi that crawled towards him had been alive once and that he had done his part in stealing that away.

A fourth and a fifth followed, the rocky beach on which he stood now filling with Voldemort's victims, their bones and muscles charmed to take his own life away.

He felt another pull against him and he gave in, his body suddenly weightless. Maybe it was the delirium from the potion, his mind was still clouded by the images it had provoked and he was still so very parched. Maybe it was the thought that he hadn't done enough, that he'd let the monsters of the night lead him astray until he himself became one. Whatever it was, Regulus didn't fight.

His body splashed against the water, a hundred hands pulling at the fabric of his clothes, weighing him down. He was pulled beneath the surface, the terror he had felt drowning alongside him. He had wanted a way out, and as he let out a final scream, letting the putrid water fill his mouth, his lungs, he supposed he had found one.

Title/Link: Regrets Beneath

School and Theme: Ilvermorny and The Coffin Shop

Main Prompt: Regulus

Additional Prompts: Horror, Fallen Hero

Year: 3

Word Count: 2101

Summary: The cave in which Lord Voldemort hid one of his Horcruxes holds things that are more terrifying than the inferi that fill the sea. For Regulus that's old scars and memories of his brother more painful than the water that threatens to drown him.

Trigger Warnings: implied abuse