The battlefield shifted on its axis.

Regulus Black. Gone for months. Presumed dead. Hunted, missing, vanished. Now stood in the middle of no-man’s-land like a revenant from the deep.

But this was not the boy they remembered.

He was barefoot, dripping water. His robes—what was left of them—were shredded, soaked and tangled with rope, kelp, and rusted chains. His left arm was missing from the elbow down, just a bandaged, scarred stump held to his side. Claw marks raked across his chest, his throat, one deep scar tearing down over his eye. That eye burned gold now. Unnatural. Like a wolf or a god.

In his remaining hand, he held a locket. Gold. Ancient. Familiar.

He stared straight at Voldemort. And then, without a word, he threw the locket down into the mud at Voldemort’s feet.

It sizzled. Melted. The Horcrux was dead.

“YOU—” Voldemort’s snarl shattered the silence. He raised his wand with a sharp snap. “TRAITOR!”

But Regulus didn’t flinch. He stepped forward. And again. And again.

The Death Eaters recoiled. Voldemort himself took a step back.

Regulus’s voice rasped like he’d swallowed sea salt and glass: “In all my years of living… it isn’t very often that I get pissed off.”

A ripple of disbelief swept through both sides. Sirius stared like he’d seen a ghost. James whispered, “Is this real?”

Regulus kept walking. Closer. Slower. “I tried to chill with the waves. I tried,” he growled. “But damn, you crossed the line.”

“You dare—” Voldemort hissed.

“I’ve been so gracious,” Regulus spat. “And yet, you hurt a friend of mine.” His voice cracked with fury. “That’s right. The elf you poisoned and left to die is mine.”

The locket sparked where it lay broken in the mud.

Regulus bared his teeth. “I’m left without a choice and without a doubt.” He raised his wand—burned black and jagged like driftwood. “Guess the pack of wolves is swimming with the shark now.”

“Merlin’s balls,” Fabian whispered. “What is he?” said Marlene.

“I’ve gotta make you bleed,” Regulus growled, “I need to see you drown.” His eyes were glowing now. Unholy. “But before you go—I need to make you learn how.”

A wind picked up. No one cast it. The air shifted. Water began to ripple in every puddle. Every stream. Every drop of rain left on the ground.

“Ruthlessness,” Regulus said softly, “is mercy upon ourselves.”

Something stirred in the mud.

“You are the worst kind of prodigy,” he snarled, turning his full attention back to Voldemort. “’Cause you’re not even great. A pureblood who reeks of false righteousness. That’s what I hate.”

The ground trembled. Pale hands clawed out of the dirt. Inferi. Inferi were rising.

“Shit—shit—” Remus gasped. “They’re his,” Lily whispered. “He’s controlling them—”

Dozens. No—hundreds of Inferi pulled themselves out of the ground and the puddles, clawing their way from the earth like a plague.

Regulus didn’t look at them. He didn’t have to.

“‘Cause you fight to gain power,” he spat at Voldemort, “but won’t work and get your hands dirty. I mean—” He laughed. “You totally could’ve avoided all this had you just killed my elf.”

He tilted his head. Smiling too wide. “But nooooo.”

Screams broke out as the Inferi attacked. They didn’t touch the Order. They only attacked Death Eaters.

“YOU’VE LOST CONTROL—” Voldemort shouted.

“You are far too cowardice,” Regulus snarled. “Mercy has a price. It’s the final crack—we’re bound to break the ice now.”

Death Eaters fell screaming, dragged into the dirt. Torn to shreds. Burned. Drowned. The army of 200 was shredded in seconds.

“When does a ripple,” Regulus said, voice like thunder, “become a tidal wave?” He pointed his wand. “Forty-three. That’s how many you’ve got left under your command.”

Voldemort’s face twisted. He raised his wand—screamed a spell— Regulus met it. A blast of dark light clashed in the middle.

“When does man become a monster?” Regulus roared. “I am your darkest moment!”

They were duelling now. Spell after spell. Light and shadow clashing like fire and tide. The battlefield lit up with every strike.

“The monster that always draws near,” Regulus growled, stepping through the curses like a beast, feral and untouchable. “Any last words?”

Voldemort snarled and threw a curse—Regulus caught it on his ruined arm, wincing but grinning like it only fed him.

“You reveal your name,” Regulus said, voice breaking, “then you let him live. Unlike you, I’ve got no mercy left to give, ’cause—”

They clashed again. The entire earth shook with the force of the blow.

“Ruthlessness is mercy upon ourselves!”

And then Regulus was on him. He tackled Voldemort into the mud, disarmed him with a blast that sent the wand flying. He straddled the Dark Lord’s chest, wand pressed to his throat.

Voldemort gasped, struggling— Regulus smiled.

“And now,” he whispered, “it is finally time to say goodbye.” He leaned down. “Today you die.”

A flash. A scream.

And Voldemort was gone.

Silence.

For one perfect breathless moment, the world stopped.

Then someone screamed. Then everyone did.

The Death Eaters ran. The Order stared.

Sirius collapsed to his knees. James was gripping his wand like it was the only thing keeping him alive. Marlene was sobbing. Lily had covered her mouth. Remus was staring like he couldn’t breathe. Fabian and Gideon looked like they’d forgotten how to speak. Frank was holding Alice, and Dorcas was shaking, one hand over her heart.

Peter had fainted.

Regulus stood slowly, trembling, covered in blood and seaweed, still breathing heavy like a monster that hadn’t finished its hunt.

He turned. Looked at the Order. Looked at Sirius.

And said, voice barely human, “The line between naïveté and hopefulness is almost invisible. So close your heart. The world is dark.”

He looked down at his own hands. Then, softer: “Ruthlessness… is mercy.”

He raised his wand. Looked up at the sky.

And whispered: “Die.”

The Inferi collapsed like puppets. The water went still. The air cleared.

And Regulus—Regulus Black, 18 years old, broken and bleeding and risen from the sea—closed his eyes.

He didn’t fall. He didn’t run. He just… stood.

The last wave had broken. And the world would never be the same.

The battlefield was barely holding together.

Smoke curled up from blackened grass. Fires crackled from the ruins of what once might’ve been homes. Inferi corpses lay motionless and slowly rotting under the cleansing silence, and the only thing louder than the wind now… was the pounding of desperate footsteps.

“RETREAT!”

The remaining Death Eaters—forty-three reduced to a scrambling, terrified handful—broke rank and fled into the smoke. Some Disapparated with loud cracks. Others tripped over their own dying comrades trying to run, dragging broken limbs and blood-soaked robes with them. Panic swallowed them whole.

But not all of them fled.

Two masked figures lingered just out of reach. One was tall, blood on his collar. The other smaller, shoulders heaving.

The smaller one—trembling—took a single step forward. A hand, hesitant and shaking, lifted—reaching toward the storm-stained silhouette still standing at the battlefield’s heart.

Regulus didn’t move.

The tall one grabbed the other’s arm. Pulled. A tense, whispered exchange passed between them, and then the taller one wrenched them both into smoke. They vanished into shadow.

Sirius blinked, eyes wide, breath caught. “That was them. That was fucking them—” “No time,” Remus rasped, dragging him up. “We’ve got to—go—GO—”

And then the spell broke.

The Order—finally unshocked, still raw and reeling—sprang into action. Shouts rang out. Stunners and binders flew into the air like firecrackers. James and Lily sprinted after fleeing Death Eaters, Frank and Alice close behind. Fabian and Gideon split up, covering the flanks. Peter regained consciousness with a scream and immediately started vomiting into the dirt.

They were trying to salvage what they could. Capture who they could. Secure the wounded. Secure the dead.

Except Dorcas.

Dorcas didn’t move.

She was still standing in the middle of the field, her wand forgotten, her gaze fixed.

On him.

Regulus Black.

Wet. Bloodied. Inhuman. Standing over the corpse of a dark god.

She stumbled once, then again. Someone screamed her name—maybe Marlene, maybe Sirius—but she didn’t stop.

Regulus turned his head slightly, looking at her out of the corner of a single golden eye. That one eye blinked slowly, like a wolf lazily sizing up a bird. No reaction. No emotion. No recognition.

But he didn’t raise his wand.

Dorcas didn’t care. She ran.

She reached him in seconds, threw her arms around him—and pulled him in, tight and shaking and sobbing. She buried her face in his shoulder, in the seaweed and blood and rope. Her whole body shook.

And he let her.

He didn’t hug back. Not exactly. But his remaining hand curled lightly, just barely, around her side. His head tilted. His chin dropped. He let himself lean.

For a moment, she held the monster who ended the war. And the monster let himself be held.

The rest of the Order slowed to stillness. The last of the Death Eaters were gone or stunned, floating in conjured nets or bound with ropes, unmoving in the grass.

James was standing over one of them, wand lowered. “He really did it,” he whispered. Lily didn’t answer. Her mouth opened. Then closed. Then opened again. “He… he did it,” Alice breathed, sounding like someone saying the words just to believe them. “Is he—” Peter squeaked, voice dry. “Is he really dead?”

Silence.

No one moved. No one breathed.

Regulus turned slowly. Pulled away from Dorcas, who let him go without a word.

He walked across the torn battlefield, dragging his broken body over the cracked, bloodsoaked ground. His eyes didn’t blink. His limbs didn’t tremble. He moved like something already half in the grave.

He stopped beside the body.

Lord Voldemort. The Dark Lord. Tom Riddle. A man who’d torn the world apart and made everyone believe he couldn’t be stopped.

Regulus crouched. Took a breath. Then slowly, coldly—

He stabbed his wand through the corpse’s eye socket.

No movement. No spell. No shadow. No scream.

Nothing.

The Dark Lord was dead.

The war was over.

A scream broke the air. Someone fell to their knees. Someone else started sobbing. Others collapsed entirely, burying their faces in their hands or in each other’s shoulders, too overwhelmed to speak.

Dorcas watched him, hand over her heart, lips trembling. Sirius didn’t move. He was staring at his little brother like he was seeing a ghost.

Remus was the one who said it, barely a whisper: “…He did it.”

Regulus stood up slowly, wiping his wand on his torn robes. He turned, eyes scanning the crowd—burned gold, hollow, storm-drowned.

The Order looked back.

No one said anything. Because no one knew what the fuck to do now.

The silence stretched long and heavy, like fog over a grave.

The only sound was wind shifting through the scorched grass, licking the tips of ruined stone and smoldering earth. Bodies were still, spells gone quiet. The Order stood stunned in the battlefield’s ruin, staring at the boy who had ended a war.

The boy who didn’t look like a boy anymore.

Regulus Black—once the sharp-eyed heir of a pureblood dynasty, now a creature torn from the depths of some sunless sea—stood barefoot in the mud, staring back at them.

And they stared.

Slowly, the crowd began to shift. Lily moved first, a few steps forward. Then James. Frank. Remus. All of them, like pulled by tide, creeping in a little closer, unsure whether to be afraid or to weep.

Because Regulus wasn’t just hurt. He was changed.

His skin shimmered faintly under the moonlight, patches of slick scales peeking through bloodied robes and shredded sleeves. Gills fluttered faintly at his neck. One of his ears—now finned and ridged—twitched when the wind touched it. His teeth, visible as he breathed, were needlepoint and glinting wet. His eyes—one ruined, one golden—had slit pupils now. Serpentine. Deep. Drowning. His fingers ended in claws, sharp and blackened. His very bones seemed more angular, stretched, like something wearing human skin too small for it.

He looked like a siren that had crawled from the dark and devoured its own myth.

Marlene let out a noise somewhere between a sob and a swear. Mary covered her mouth with both hands. Alice was holding Frank’s arm like she might fall.

Dorcas stood nearby, frozen again, watching with too many feelings on her face to name.

Sirius’s breath hitched.

He looked like he might be sick. Or scream. Or collapse.

But he didn’t. He ran.

“Regulus—”

Everyone turned. Sirius shoved past the others, eyes wild, his hands trembling, sprinting across the burnt ground. He didn’t even think—he just acted.

Because it didn’t matter what Regulus had done. Didn’t matter that he’d disappeared. Didn’t matter that he’d worn the mark or vanished or betrayed them or joined the other side—

Because that was his brother. And he was alive. And he was bleeding.

Regulus didn’t move when Sirius reached him. Just tilted his head slightly. Watched.

And then Sirius threw his arms around him.

Regulus made a soft, startled sound—more exhale than voice. But he didn’t fight it.

He let Sirius pull him in. Let his big brother wrap him up, clawed hands resting awkwardly against Sirius’s back.

Sirius buried his face in his hair, whispering, “You stupid fucking brat—what did you do—what the fuck—what the fuck—”

That was all it took. The dam burst.

The rest of the Order rushed in at once, shouting over each other—

“Is that really him—?” “What the hell happened—” “Where did you go—” “Are you hurt—how are you alive—” “WHAT THE FUCK IS WRONG WITH YOUR EYES—”

“STOP!”

Regulus’s voice cut through the crowd like a blade across glass.

They froze.

Because his voice was… not a voice.

It slurred like water through stone. Hissed. Echoed. Multilayered and melodic and terrifying, a rasp and a growl wrapped in something far too beautiful to be human. It was the sound of being dragged under. Of your last breath before the sea swallows you.

Everyone stared. No one dared speak.

Regulus exhaled through sharp teeth.

“…You want answers,” he rasped, voice flowing like a haunted song. “Fine. You’ll have them.”

He looked up, gaze sweeping the ruined field. The wind howled, carrying the scent of blood and salt.

“I was seventeen when I found it,” he said. “The locket. The one I gave you tonight. It wasn’t just a trinket. It wasn’t just cursed.”

He paused. “It was a Horcrux.”

A beat. Silence. Confusion.

“A what?” James asked.

Regulus blinked slowly. “A Horcrux,” he repeated, tone clipped and slurring, like the word burned his tongue. “A piece of a soul, torn and sealed. Voldemort split his soul. Shoved pieces into objects. To make himself immortal.”

Everyone stared.

“That’s not possible,” Lily whispered. “That’s madness,” Remus muttered.

Regulus snarled. “And yet he did it. Seven times.”

Sirius flinched.

“The locket was one,” Regulus continued. “I only knew because of Kreacher. Voldemort used him to test the protections in the cave. Forced him to drink the poison. Left him there to die.”

He bared his teeth. “I sent Kreacher home. Then I drank it myself.”

No one breathed.

“The Inferi dragged me under. I should’ve died.” His voice dropped to a growl. “But I didn’t. The locket was still around my neck when they pulled me down. Dark magic. Dark blood. Ancient wards. The lake was old, and I was my mother’s son.”

He gestured to his gills. His teeth. The scales on his wrist.

“Magic reacted. Changed me. Reforged me.”

“You—transfigured yourself?” Frank asked, voice too high.

“No. The magic broke me,” Regulus hissed. “And rebuilt what was left.”

He stepped back. The crowd shifted.

“The months after, I hunted them. All of them. The diary. The cup. The ring. The diadem. The snake. The soul fragments left behind.”

“Alone?” Gideon croaked. “You did this alone?”

“Yes.” “But—” “You—”

Regulus raised a hand and they fell silent.

“I had to. No one else even knew. He would’ve won. You know he would’ve won.”

He looked at them all. At Sirius. Dorcas. Lily. All the faces of the Order. All the wide, exhausted eyes.

“You weren’t supposed to see me again,” he said quietly. “But I couldn’t… let him win.”

The wind stirred again. This time softer. Like it was listening.