Sirius stood on the pavement for far longer than he intended to.
That made him annoyed with himself. He had faced far worse things than this damn house. He had been gone for the better part of a decade, had crossed three continents and fought in wars that the wizarding world didn't officially acknowledge had happened, had acquired a wife and four children and a castle above the North Sea, and Grimmauld Place looked precisely as it always had.
The same dark terrace. The same iron railings with their serpent motif, oxidized now to a greenish black. The same quality of shadow that number twelve generated regardless of what the sky was doing, as though the house had opinions about light and had been enforcing them for centuries. The neighboring houses pressed close on either side, the Muggle residents behind their doors entirely unaware that number twelve existed at all, which was how it had always been and how it would remain.
And yet here he was. His hands steadier than he would like to admit they had any right to be, given what was on the other side of that door.
He had told himself he was never coming back. He had meant it, at sixteen, with the complete and absolute conviction of someone who does not yet know how many promises the future makes impossible. He had meant it through the war, and through the Custodian years, and through every year of the decade since. He had been very consistent about meaning it.
And yet here he was.
Every avenue he had explored for Regulus had come back empty. No records. No sightings. No trail of any kind, magical or Muggle, to follow. Whatever Regulus had done before he vanished, he had done it in a way that left nothing behind for anyone to find. The only place that remained unexamined was the place Sirius had promised himself he would not examine.
There could still be something here. There had to be.
He thought about the morning he had left. Rigel in the doorway of the family wing at Blacktide, watching him with those blue-green eyes that never missed anything. Corvus beside him, thinner than Sirius would have liked, leaning slightly on the doorframe with the careful management of energy that had become so habitual it no longer looked like management. Lyra, who had assessed the situation and taken Corvus's hand without being asked. Alphard, who had not understood the concept of departure but had understood that something was happening and had attached himself to Sirius's leg with both arms and said no with the conviction of someone making a constitutional argument.
He had extricated himself from Alphard with some difficulty.
Esme had stood beside the children and looked at him in the way she looked at him when she understood something he hadn't said. She had considered coming. But they had decided together that they did not like the idea of leaving the children alone too long, even with the house elves. Especially since it is very new and the two new parents are trying to establish relationships with their new children.
And where Sirius was going, he needed to face it himself.
"Come back, okay, Papa?" Corvus had asked, before the departure. Quietly. Carefully. With the specific phrasing of a child who has learned that asking for things is a risk worth taking, but only barely.
Sirius had looked at him for a moment.
"I will, little star," he had said, and meant it in the way you mean the things that matter most.
He carried that with him onto the pavement outside number twelve.
He took a long breath.
He went in.
*****
The dust hit him before anything else did.
Sirius started coughing the moment he opened the door.
Then the smell. Damp. Old stone. Something underneath that had no precise name — the accumulated residue of a house that had been many things and had let none of them go. Dark magic did not dissipate cleanly. It settled into walls and floors and the grain of old wood, and the house at Grimmauld Place had been home to generations of people who had not been careful about what they left behind.
He stood in the entrance hall and let the lights come up slowly, reluctantly, at his magical signature.
Neglect was the first word that came to mind. The house was not abandoned. Sirius knew that. He also knew that his parents both died in this house. His father first and then his mother. Sirius never went to their funeral. His father was because his mother sent a scathing howler to him not come. And his mother? That reason was too obvious.
But the surfaces. The floors under a layer of dust thick enough to hold the impression of his own footsteps as he moved. The mounted elf heads along the wall, which had always been there and had always turned his stomach, now additionally draped in cobwebs that softened their outlines into something almost ghostly. The umbrella stand made from a troll's leg, still by the door, still inexplicable.
Nobody had cleaned this house in years.
He stood with that knowledge for a moment.
He had not let himself think much about Kreacher in the years since he left. Kreacher was part of the house, and the house was something he had sealed away and declined to revisit, and the seal had held well enough that thinking about what he had left behind in it had not been a daily occupation. But standing here now, looking at the dust and the cobwebs and the comprehensive evidence of a house that had been running without maintenance for a very long time, he felt something he had not expected.
The elf was gone. Whatever age or isolation or the severing of the family magic had done to Kreacher in the years since Sirius left, it had apparently done it completely.
He had not thought about what that would feel like.
He moved further in.
*****
Sirius still knows where he is going. Memories he didn't want to resurface are present in his head whenever he looked at every surface of the house.
His father's study, door closed. He did not open it. Orion Black had been a man who had treated indifference as a form of dignity and absence as a form of authority, and who had produced two sons neither of whom had been given a reliable model for what a father actually was. Sirius who now has four children promised to never be like him. He did not need to open the study to think about Orion, but he thought about him anyway.
The drawing room, where the family had gathered for the formal occasions that Walburga had arranged with the precision of someone staging an argument with reality. Here is how the Blacks behave, here is the proof of it. He looked in through the open door. The portrait of the family tree covered most of one wall, the tapestry faded now but still legible, the burned patches where names had been removed still visible as darker absences in the weave.
He did not look for his own name. He already knew it was still there. He didn't bother to think about it and turned away.
As he went further in Sirius stop on his heels. He wanted to curse.
His mother's portrait was at the end of the first-floor corridor.
He had known it was there but didn't realize that his mother has intentionally activate this portrait upon her death. Not everyone activates their portraits. He passed by his father's and that one was not moving. But his mother portrait?
She looked exactly as she always had. That was the first thing he noticed and the most unsettling. Death had not given her the quality of something resolved or historical. She was simply Walburga, suspended in paint at the height of her certainty about everything, still wearing the expression she had worn at him across every formal dinner and every disciplinary confrontation and the final screaming match that had ended with a door slamming hard enough to crack the frame.
The portrait's eyes were closed. Sleeping, or whatever portraits did in the absence of an audience. He stood in the corridor and looked at her for a long moment.
He thought about what it would have cost her to admit, even once, that she had been wrong about something. He thought about the particular cruelty of a woman who had weaponized love, who had loved her family in the most destructive way available, as a standard to be met and a judgment to be administered and never, not once, as a thing that simply existed between people without conditions attached.
He thought about Corvus in the doorway saying come back.
The contrast between those two things was so large he could not hold both in his mind simultaneously.
"Goodbye, Mother," he said to the sleeping portrait.
She did not wake. He had not expected her to.
He went further up.
*****
Regulus room was smaller than he remembered. It was intact in a way his own room had not been. He had checked his room, and it was stripped of everything personal within. The Gryffindor colors, his muggle music collection and some of his muggle posters. He felt smug seeing some of them are still up. It is obvious that they were some attempts to remove it, but Sirius was brilliant enough to make some of them permanent in his room. He would like to see the look on his mother's face when she attempted to remove those. Some of those posters were inappropriate.
Regulus room has been preserved well. There doesn't seem to be as much dust compared to the rest of the house.
Books on the shelves with markers still in them. A Slytherin scarf over the chair. The Slytherin Quidditch pennant on the wall above the desk, slightly askew, which Regulus had put up himself and which apparently no one had straightened in the years since.
Sirius stood in the middle of the room and looked at these things.
He had been furious with Regulus. For years and years, he had been furious for the choices, for the Death Eater mark, for the stubborn, maddening refusal to simply leave the way Sirius had left, for dying without ever having a conversation that resolved anything.
He picked up the photograph from the bedside table.
Him and Regulus. Somewhere in summer, both squinting into the sun. Sirius apparently saying something. Regulus laughing. That laugh, the one that had always been unexpectedly loud for someone so contained, the one that Sirius could still hear if he let himself.
Before the sorting had become a wall. Before the war had become a canyon. Before he had left and Regulus had stayed and neither of them had found a way back to the people, they had been in this photograph.
He set it down carefully, face up.
He did not know how long he stood there. Long enough for the light through the window to shift slightly, the afternoon moving toward evening.
He was still standing there when something hit him from the shadows behind the wardrobe.
It was not effective, as attacks went. But it had the absolute advantage of complete surprise, because the house was empty, and the elf was dead, and Sirius had not been braced for anything to come out of the shadows at all.
He caught a glimpse of enormous, clouded eyes and ears like crumpled leather, of a duster being brandished with more intent than technique, and then his body did what a soldier does when face with a surprise — he stepped back, cleared his wand hand, and said, sharply, "Stop."
The family magic was in the word. The command landed with the weight of a bloodline behind it, and the creature stopped mid-swing.
Sirius stared.
The house elf stared back.
He was old; older than Sirius remembered, the enormous eyes cloudier at the edges, the skin more deeply lined, the general impression of him one of a creature that had been running on considerably less than full capacity for a very long time. He was wearing something that had once been pillowcases and was now closer to a personal philosophy about fabric. He was holding the duster with both hands and was breathing in small, furious huffs.
He was alive.
"Kreacher," Sirius said.
The name came out differently than he intended. He had intended flat and controlled. What came out had something in it he had not planned for.
Kreacher's eyes narrowed. The loathing in them was old and thorough and had clearly been maintained with some care. "The blood traitor," he said. The quietness of it was worse than a shout would have been. "Kreacher thought never to see the blood traitor again. Kreacher had hoped—"
"You're alive," Sirius said.
He heard how that sounded. He could not entirely help it.
Kreacher's expression shifted into something that combined loathing with the bafflement of a creature encountering an unexpected variable. "Kreacher is alive," he said, with the precision of someone explaining arithmetic. "Kreacher has always been alive. Kreacher has been here." The pause before the last two words carried everything in it. "Alone."
Sirius looked at the elf. At the state of him. At the dust on his makeshift toga and the duster that had clearly not touched a surface in years. He looked around the room. The dust, at the preserved photograph, at the Slytherin pennant still slightly askew on the wall.
He thought about what he had left behind when he left. He thought about what it was to be bound to a house that no one came back to.
There were things he needed to say. They had been sitting in him since the moment he understood, in Grimmauld's entrance hall, that Kreacher was still here. But they were not the first thing. The first thing was Regulus.
"I'm here because of Regulus," Sirius said.
The name changed the room.
Kreacher went very still. Something moved across his ancient face — something raw and unguarded, the specific expression of a creature whose deepest loyalty had been spoken aloud without warning.
"What does the blood traitor know about Master Regulus," he said. Very quietly. Very carefully.
"I need to find him," Sirius said.
Kreacher's eyes narrowed. "Master Regulus is gone," he said. The flatness of it was not indifference — it was the flatness of something that had been said to oneself so many times it had worn smooth. "Gone into the depths. Master Regulus is gone."
"I know what everyone thinks," Sirius said. "But I may have evidence that he is still alive somewhere. I just don't know where—"
"A—alive?"
The word came out of Kreacher like something had struck him. He stumbled back a half-step, the duster falling from his hands entirely, his enormous eyes gone wide in a way that made them look almost young.
"Master Regulus — is alive?"
"I don't know for certain," Sirius said, carefully. "What I know is that he may be in a kind of coma. Somewhere. I just don't know where—"
"COMA?!"
The sound that came out of Kreacher then was not a word. It was the sound of something tearing — grief and guilt and five years of carrying something alone all arriving at once with nowhere to go. He grabbed at his own ears with both hands, the way house elves did when the self-punishment instinct overtook everything else.
"It is Kreacher's fault," he said, and his voice had gone to a completely different register — raw, wretched, the voice of a creature in genuine anguish. "It is Kreacher's fault. Kreacher left him. Kreacher left Master Regulus. He was alive and Kreacher left him — Master Regulus ordered Kreacher to go, Master Regulus said go and Kreacher went and Master Regulus was still—"
He was pulling at his own ears hard enough to make Sirius wince.
"Kreacher." Sirius took a step forward. "Stop that. Stop—"
"Kreacher left his master! Master Regulus was still breathing and Kreacher—"
The elf broke off. He had spotted something on the desk. His eyes fixed on it with the specific focus of a creature that has made a decision and located the means to carry it out, and Sirius followed his gaze to the letter opener — bronze, decorative, but with an edge — and understood immediately.
"Don't," Sirius said, and crossed the room in two steps, putting himself between Kreacher and the desk.
Kreacher looked up at him. The anguish in his face was total. "Kreacher failed," he said. "Kreacher failed his master and his master is—"
"Stop." Sirius crouched down, which put him at eye level, and spoke with the particular authority that was not a command but was something adjacent to one. "You did not fail him. He gave you an order. You followed it. That is not failure, Kreacher."
"Master Regulus was alive," Kreacher said, and the words came out in pieces. "Kreacher did not know — Kreacher thought — the potion, the Inferi — Kreacher thought there was no — but if Master Regulus was alive then Kreacher left him there—"
"You didn't know," Sirius said.
"Kreacher should have known! Kreacher should have gone back! Master Regulus ordered Kreacher not to return but Kreacher should have—"
"Kreacher." Sirius put a hand up, not touching, just present. "Listen to me. I am going to get him out. That is why I'm here. But I need you to tell me where he is."
Kreacher looked at him with those enormous wet eyes.
"Kreacher cannot," he said, and the guilt in it was immense. "Kreacher was ordered. Master Regulus placed commands — Kreacher cannot speak of the cave, cannot speak of what happened, cannot return — Kreacher is bound," and the last word came out as something close to a wail. "Kreacher wants to tell the blood traitor. Kreacher wants — Master Regulus is alive and Kreacher cannot—"
His hands were moving toward his ears again.
Sirius made a decision.
"Kreacher." His voice dropped to the register that carried the full weight of what he was, the heir of the Most Ancient and Most Noble House of Black, the bloodline that Kreacher was bound to above all commands placed on him by any individual member of it. "I am ordering you. As the heir of the House of Black, with all authority that carries — I am ordering that every command placed on you by Regulus Black regarding the cave, regarding what happened, regarding where he is — I am negating them. All of them. You are released from every instruction he gave you to stay silent."
The effect was immediate and visible.
Something passed through Kreacher like a shudder — not physical, but magical, the sensation of bindings releasing that had been in place for five years. The elf gasped, a short sharp sound, and stood for a moment with his eyes closed and his hands pressed flat against his sides.
Then he opened his eyes.
"Now, Kreacher," Sirius said. "Tell me everything."
And Kreacher told him.
It came out in pieces at first — halting, circling, the way something comes out when it has been held in for a very long time and the holding has become its own habit. But the commands were gone now, the bindings released, and underneath them was five years of a creature that had been desperate to be heard and had had no one to hear it.
He told Sirius about the Dark Lord. About the cave on the coast, and what it had been made to protect, and how Kreacher had been taken there — used, in the particular way that the Dark Lord used things, as a test for whatever enchantments guarded the basin at the center of the lake. Whether a house elf could drink the potion. Whether a house elf could survive what happened after.
He told Sirius about Master Regulus. How the young master had noticed Kreacher's condition when he returned. How he had asked, carefully, the way Regulus always asked, but with the specific quality of attention that had always made Kreacher feel that the answer mattered. How Master Regulus had spent weeks thinking before he said anything at all and then had come to Kreacher one evening and said, very quietly, that he knew what the locket was and that he intended to do something about it.
How Kreacher had begged him not to go.
How Master Regulus had gone anyway.
Sirius sat on the edge of Regulus's bed and listened without interrupting. His face was doing something complicated that he was not entirely managing to control, and Kreacher, who had spent thirty years reading the faces of Blacks, noted this and continued.
He told Sirius about the cave. The boat across the black lake. The basin. The potion that Master Regulus had made Kreacher watch him drink — every drop of it, cup by cup, while Kreacher stood at the water's edge and obeyed the command not to help no matter what he saw. What the potion had done. What Master Regulus had looked like by the end of it.
He told Sirius about the Inferi.
How they had risen when Master Regulus's hand touched the water. How there had been so many of them — hundreds, pale and silent and reaching — and how Kreacher had screamed and tried and been ordered, in a voice that had barely been a voice anymore, to take the locket and go. To not come back. To find a way to destroy it.
"And Kreacher obeyed," he said. The words came out like a wound. "Kreacher took the locket and Kreacher left. Kreacher left Master Regulus in the water with the monsters and Kreacher — Kreacher has tried to destroy the locket as Master Regulus commanded and Kreacher cannot—"
His voice broke entirely on the last word.
"The locket doesn't matter right now," Sirius said. His voice was very steady, which Kreacher understood cost him something. "We will deal with it once we get to Regulus. Until then—" He looked at the elf directly. "I'm commanding you to keep it safe. Wherever you have it hidden, keep it there. Don't try to destroy it again. Can you do that?"
Kreacher nodded, a small and miserable movement.
"Good." Sirius stood. The steadiness in him had the quality of something assembled under considerable pressure, the way a person becomes very controlled when the alternative is not being controlled at all. "Now. The cave, Kreacher. Where is it?"