Chapter Text
The fire in the drawing room of Number Twelve, Grimmauld Place, had burned down to little more than glowing embers. Regulus Black sat hunched in a high-backed armchair, its velvet worn thin in places, staring at the ancient clock on the mantelpiece. He had been watching its hands crawl for what felt like hours.
It had been hours.
He’d sent Kreacher with the Dark Lord hours ago. The elf was to follow orders, to help with whatever task the Dark Lord required, and then to return. A simple instruction. A command.
But the elf hadn’t returned.
Regulus’s leg bounced with a nervous energy he couldn’t suppress. He knew, with a cold, sick certainty that had been growing in his gut all evening, that the Dark Lord did not place value on the lives of others. Magical creatures, to him, were tools to be used and discarded. A house-elf would mean nothing to him. Nothing at all.
The guilt was a physical weight on his chest. He knew this. He had known it when he’d offered Kreacher’s services, a bright, eager token of his own loyalty. He had been so desperate to prove himself. After months, of watching his fellow Death Eaters revel in torture and murder, he knew he didn’t have the stomach for it. He flinched at the Cruciatus Curse. He looked away from the blood. They noticed. The whispers followed him: too soft, too weak, too much like his brother. Offering Kreacher was supposed to be different. A service. Proof that his commitment to the cause was absolute.
And he did believe in the cause. Or, he had. The idea of a world ruled by wizards, a return to true order, it made sense. It was only logical that purebloods, the keepers of ancient magic and tradition, should be at the top. That was his heritage, his birthright.
But lately, a treacherous little voice had started whispering doubts. The Dark Lord’s methods were… excessive. He didn't just want order; he wanted utter subjugation. He didn't just want purebloods in power; he wanted Muggle-borns erased. Sometimes, Regulus wondered if the Dark Lord even cared about their world at all, or if he simply wanted to burn it down and build something monstrous from the ashes.
He should stop thinking like this. This was the path that led to his brother.
Sirius.
A pang of longing, sharp and unexpected, shot through him. His brother, the blood traitor, who had run off to live with a family of Gryffindors and Muggle-lovers. Sirius chose them. He chose ‘mudbloods’ and blood traitors over his family. Over him. There was no lost love between Sirius and their parents, that was true. Regulus couldn’t remember a time when Sirius hadn’t been at odds with them, a constant storm of slammed doors and furious shouts. Sirius had never loved them.
But he had loved Reg. Once. He had been the one to chase away the monsters under the bed, the one to sneak him treacle tart after dinner. He was his brother. Until he wasn’t. Until Regulus wasn't enough to make him stay.
A sharp, echoing *CRACK* shattered the heavy silence of the room.
Regulus jolted, his heart hammering against his ribs. He spun in his chair, his hand flying to his wand.
Kreacher stood in the middle of the faded Turkish rug. But it was an elf Regulus barely recognised. His usually large, bat-like ears were drooping, plastered to his skull. His skin, normally a healthy, if wrinkled, grey, was pallid and slick with what Regulus could only assume was a mix of water and sweat. His enormous eyes, usually a cloudy green, were bloodshot and ringed with red, and tears were carving clean tracks through the grime on his cheeks as ugly, heaving sobs tore from his tiny frame.
Regulus didn’t even know Kreacher could cry.
He was on his feet in an instant, crossing the room in three quick strides. He dropped to his knees before the elf, heedless of his fine robes. “Kreacher!”
The moment Kreacher registered his young master’s presence, the dam truly broke. He lurched forward, gripping the fabric of Regulus’s robes with surprising strength.
“Young Master Regulus asked Kreacher to come back!” The elf’s voice was a wrecked, high-pitched keen, thick with tears. “Kreacher had to come back! Kreacher promised! Kreacher had to come back!”
Regulus’s stomach plummeted. He wrapped his arms around the shivering, sopping creature, feeling the violent tremors wracking his small body. “You did a good job, Kreacher. You came back. You did exactly what I asked. But what happened? What did he make you do?”
Kreacher just sobbed harder, burying his face in Regulus’s shoulder, his whole body shaking with the force of his weeping. The firelight flickered, casting long, dancing shadows on the wall behind them, and for the first time, a deep, primal fear that had nothing to do with his parents or the Dark Lord took root in Regulus Black’s heart. Something was terribly, horribly wrong.
Regulus held the sobbing elf for a long time, murmuring soothing words his own mother had never once offered him. He didn't know how to comfort anyone—the Black family had never taught him that, only how to command. But Kreacher was his. His responsibility. His fault.
"Kreacher, you're safe," he whispered, feeling the elf's ragged breaths gradually slow against his chest. "You're home. You came back."
Finally, the sobs subsided into wet, shuddering gasps. Regulus gently pulled back, keeping his hands on Kreacher's bony shoulders. The elf looked utterly wrecked—his tea-towel was filthy, torn in places, and there was a wild, haunted look in his enormous eyes that made Regulus's blood run cold.
"Kreacher needs to tell young master," the elf whimpered, his voice raw. "The Dark Lord... he made Kreacher do terrible things. Kreacher had to obey."
"I know," Regulus said softly, though he didn't know. Not yet. "Come. Sit by the fire. You're freezing."
He helped the trembling elf to the hearth, conjuring a thick cushion with a wave of his wand. Kreacher sank onto it gratefully, still shaking. Regulus knelt beside him, summoning a warm blanket from the back of a chair and draping it around the elf's small shoulders.
"Warm some milk," Regulus murmured to his wand, and a moment later a steaming cup floated over. He pressed it into Kreacher's hands. "Drink. Slowly."
Kreacher stared at the cup as if he'd never seen one before, then clutched it like a lifeline. The warmth seemed to help. His trembling eased, just slightly, and he took a small, tentative sip.
"Now," Regulus said, his voice steady despite the dread pooling in his stomach. "Tell me everything. From the beginning."
Kreacher's eyes filled with fresh tears, but he nodded, clutching the blanket tighter.
"The Dark Lord took Kreacher to a cave, young master. A terrible place. By the sea." The elf's voice was a whisper, haunted. "There was a cave hidden in the cliffs. Kreacher had to steer the boat across the dark water—such dark water, young master, Kreacher could feel something beneath—"
"Something?" Regulus interrupted sharply. "What kind of something?"
"Kreacher doesn't know," the elf whimpered. "But it was cold. Hungry. Kreacher could feel them watching. Waiting."
Them. Not it. Regulus's grip on his wand tightened. "Go on."
"They came to an island in the middle. A small island with a stone basin. The basin was full of liquid, young master. Clear as water, but Kreacher knew it wasn't water. It felt wrong. Evil." Kreacher's voice dropped even lower. "The Dark Lord made Kreacher drink it."
The words hit Regulus like a physical blow. "He made you— Kreacher, what did it do?"
"Kreacher doesn't know how to explain," the elf said, tears streaming again. "At first, it was just... cold. Then the thirst came. Not ordinary thirst, young master. The worst thirst Kreacher has ever felt. Kreacher's throat closed up. Kreacher's tongue swelled. Kreacher would have given anything for water. Anything. And every time Kreacher tried to stop drinking, the potion... it made Kreacher keep going. It forced Kreacher."
Regulus felt sick. Compulsion magic. The Dark Lord had embedded compulsion magic into the potion itself.
"And the dead things in the water," Kreacher continued, his voice breaking. "They kept reaching for Kreacher. Pulling him down. Kreacher saw things. Terrible things. Faces Kreacher knows. Faces Kreacher loved—"
He broke off with a wail, and Regulus didn't need to ask whose faces. His mother. His father. Walburga and Orion Black, twisted and rotting, reaching for their house-elf with dead hands.
"What happened then?" Regulus asked, his voice barely above a whisper.
"When the basin was empty, the Dark Lord... he put something in it. Kreacher saw it, young master. A locket. An old locket, heavy and cold. Then he filled the basin again with more potion—the clear stuff—and he left." Kreacher's sobs returned, fresh and raw. "He left Kreacher to die on that island. With the dead things. Kreacher couldn't Apparate, young master, the magic wouldn't let Kreacher leave. Kreacher was so thirsty. Kreacher was going to die there, alone in the dark—"
"But you didn't," Regulus said firmly, gripping Kreacher's shoulder. "You're here. How did you escape?"
Kreacher looked up at him, his enormous eyes glistening. "Kreacher is a house-elf. House-elf magic is different, young master. The Dark Lord didn't think of that. When Kreacher couldn't take the thirst anymore, when Kreacher knew he would die, Kreacher Apparated. It hurt. It hurt so much. But Kreacher had to come back. Young master told Kreacher to come back."
Regulus stared at the elf, a complex storm of emotions raging within him—horror at what Kreacher had endured, guilt for sending him into it, and a cold, creeping curiosity about what the Dark Lord was hiding in that cave. A locket. Why would the Dark Lord go to such lengths to hide a locket?
"Kreacher," Regulus said slowly, his mind racing. "This locket. What did it look like?"
Kreacher sniffled, wiping his nose on the blanket. "It was heavy, young master. Gold, Kreacher thinks. With a serpent twisted into the shape of an S. Green gems for eyes. Kreacher felt... cold when Kreacher saw it. Wrong."
Regulus's breath caught in his throat. A serpentine S. Green gems. He'd seen that locket before, in a dusty case at Borgin and Burkes, years ago when his mother had dragged him through Knockturn Alley. It had belonged to Salazar Slytherin himself. It was a relic of their world, of pureblood heritage.
Why would the Dark Lord hide something so precious in a cave, protected by lethal magic and an army of Inferi? What could possibly justify such elaborate defenses?
Regulus didn't know. But he intended to find out.
Before he could ask another question, before he could even fully process the implications of what Kreacher had told him, fire erupted on his left forearm.
White-hot, searing pain. The Dark Mark was burning.
Regulus cried out, clutching his arm as the skin seemed to writhe beneath his sleeve. Kreacher shrieked, scrambling backward, his eyes wide with terror.
"Young master! The Dark Lord calls—"
"I know," Regulus gasped through gritted teeth, staring at the black skull and serpent writhing on his skin like a living thing. He was being summoned. Now, of all times. After everything Kreacher had just told him.
The pain intensified, an urgent, demanding pull. The Dark Lord wanted him. Expected him. And Regulus realized, with a clarity that cut through the agony like ice water, that he had a choice to make.
He could go. He could answer the call, bow and scrape, pretend he knew nothing, continue being the obedient little Death Eater everyone expected him to be.
Or he could stay. He could listen to the voice in his head that sounded far too much like Sirius, telling him that some things were worth fighting for. That some lines shouldn't be crossed.
The Mark burned on.
Regulus looked at Kreacher—his elf, his responsibility, the creature the Dark Lord had so casually tried to murder. He thought of the cave, the potion, the Inferi waiting in the black water. He thought of the locket, pulsing with dark magic at the bottom of that stone basin.
He thought of his brother, who had chosen what was right over what was easy.
The Mark seared his flesh, demanding obedience.
Regulus Black looked at the burning skull on his arm, and for the first time in his life, he made a choice that was entirely his own.