note: this is au. i moved around ages and i'm not really sure how, but regulus is in sixth year and sirius is in seventh in this fic

for quidditch league, round 3, kenmare kestrels, chaser 3: The Castle of Otranto by Horace Walpole: Write about someone who ignores an important warning. / optional prompts: 3. (season) winter; 6. (setting) nighttime; 8. (object) locket

thank you to ari for betaing!

1722 words by gdocs

"Do not —" Regulus says, gasping for air as he tries to fight his way out of the lake. He's weak from the potion, and he probably couldn't conjure up enough energy to cast a spell, even if he could remember how to get rid of Inferi. "Do not tell anyone about the locket." He's breathing hard, the cold air not helping him catch his breath. Hands grab at his feet and Kreacher isn't sure what else he can do other than stand there in horror as Regulus is pulled further in. He snaps his fingers, but even his house-elf magic doesn't do anything to dispel the animated corpses. "Anyone who knows is in danger. Destroy it and do not tell —!"

There are hands grabbing at his arms now, at his torso. Regulus lets out a little yell of shock, but he's weak, too weak to do much fighting back. He gets pulled under, leaving Kreacher alone with the locket and Regulus' last order.

…

Sirius can't stop craning his neck around and scanning the Great Hall. More specifically, he can't stop scanning the Slytherin table. There's a sea of silver and green robes, but among them Sirius can't spot —

"Mate," James says, making Sirius snap his head back around to the Gryffindor table. "Your anxiety is becoming contagious."

"Sorry," Sirius says, but the apology doesn't mean he's going to stop drumming his fingers on the table and glancing behind him for some sign of —

"You do realize people still have today and tomorrow to come back from holiday, right?" James tells Sirius. Sirius stares pointedly ahead, not letting himself glance at James or at the Slytherin table, but he can still feel James' eyes on him. "It's fine."

"Right," Sirius says, apparently limited to one word replies. He knows that — it's not unusual for people to come back on the second or third day after break. Even Peter and Remus aren't back from their holidays yet.

Still, Regulus has always been back on the first day.

There's a bad feeling in Sirius' stomach. One that he, for some reason, can't seem to shake.

…

Term starts.

Term starts, and Sirius can't help but glance over at the Slytherin table during every meal. Regulus pointedly is not there.

Sirius knows that while he stares at the Slytherin table, trying to pretend that Regulus could magically just appear there, his friends are staring at him.

James doesn't say it's okay. Sirius wouldn't believe him if he did.

…

Sirius has been pacing outside of Dumbledore's office for the past twenty minutes. He wants to speak to him, he does, but he's not even sure what he'd say. He has no doubt that Dumbledore would try and help him — he was the one, after all, who let Remus into his school despite him being a werewolf. Sirius doesn't think that there's much Dumbledore wouldn't do for his school.

Still, his mind is blank. He probably shouldn't even be worrying. Didn't he give up the right to worry about his brother when he left him? Sirius was the one who chose to leave Regulus. Regulus didn't choose it. And now Regulus is —

Well, Sirius doesn't know, and that's the problem.

Sirius pauses his pacing when he hears someone else enter the hallway, but his eyes are still on the floor.

"Mr Black?" the person asks, and Sirius looks up, lips pursed, to find McGonagall standing there. She's looking at him with her brows furrowed and a slight frown on her lips and Sirius' stomach churns. "Are you alright?"

"I was hoping I could speak with Professor Dumbledore," he tells her, trying to keep a face of impassiveness.

"Professor Dumbledore is away on some other business," McGonagall tells him. He can faintly feel his heart drop. "He won't be back until next week. Is there something I can help you with?"

Sirius shakes his head.

…

The week before the full moon is always marked by Remus waking up in the middle of the night, sweating from a high fever. They've been living in the same room for seven years, and by this point they don't really wake up from Remus' gasping for air anymore. It's become normal to them at this point.

Tonight, though, Sirius hasn't even gone to bed at all. He hears Remus wake up for the third time and sighs, rolling over to face Remus in the darkness.

"Do you want to go walk outside for a bit?" he asks, his whispered question cutting through the silence of the night. There's snow on the ground and the air is cold. Sirius figures that the cool of the night might help Remus' fever, and he needs to walk anyway. He's restless.

"Sure," Remus says, not asking why Sirius is awake, which Sirius is thankful for.

They get dressed fairly quickly, and within minutes they're outside, their breath visible in the air as they walk around the grounds. The Black Lake's been frozen over since before their Christmas holiday and usually Sirius would take the opportunity to slide across it to make Remus laugh and scold him, but tonight he doesn't feel much like doing anything like that.

Instead of dispelling some of his anxiety like he had hoped, the cold makes him just that — cold. So now he's cold and anxious.

It seems to help Remus, though, which makes Sirius feel a bit better.

"Do you want to head back in?" Remus suggests, after a while of them stomping through the snow.

"Sure," Sirius replies, digging his hands so far into his pockets that they're scraping the bottom. He lets out a deep exhale, watching the mist for a few seconds before walking back towards the front door of the castle. Sirius doesn't even walk three steps before he trips over his feet, falling forward and landing with his face in the snow.

"Are you alright?" Remus asks, going forward to grab Sirius' arm. Sirius can feel that Remus' grip is weak — he's not going to actually be able to help Sirius up — and he just doesn't want to move right now. He wants to just stay there in the snow.

"I'm fine," Sirius tells him, rolling over onto his back. "You can go in, if you want. I'll be there soon."

He must be sending off pretty strong "I want to be alone" vibes, because after a second of hesitation, Remus does leave him. Maybe Remus is just cold.

Sirius lays there for a few seconds, letting his body go a little bit numb. He should get up, he thinks, but his brain is filling with thoughts of Regulus and it feels like it's weighing him down.

A loud crack sounds in the courtyard, and that gets Sirius sitting up quickly and looking around. He's already on edge from Regulus not being at Hogwarts and his lack of ability to do anything about it, and he doesn't have his wand on him. The crack sounded like someone Apparating, though, and Sirius knows that no one can do that on Hogwarts grounds. He's fine. It's fine.

Slowly, Sirius gets to his feet and slowly heads towards the door, trying to watch his step. He's also watching the grounds in front of him, just in case.

"Master," a voice says from behind him and Sirius' heart freezes for a second. He whips around, really wishing he had his wand on him and he looks down to see an awful sight in front of him.

"Kreacher," he says slowly. Sirius hates his parents, but he thinks he would rather see them right now than Kreacher, who's standing in front of him, clutching the chain of a locket in his hand.

"Kreacher has been waiting until Master Sirius was alone to speak to him," Kreacher says, giving the tiniest nod as a form of a bow. "Master Sirius has not been alone. Kreacher thinks that Master Sirius might —" he pauses, like the words are hard to get out. "Master Sirius might help Kreacher."

The two of them look at each other for a second, and then it registers to Sirius that Kreacher probably knows where Regulus is. Regulus always had a weird affinity for Kreacher that Sirius never understood. Still, if Sirius could use it —

"Where's Regulus?" Sirius demands. He's fairly sure that, as a Black, he still has control over Kreacher, no matter what animosity he and his parents feel towards each other.

"Master Regulus is dead," Kreacher says, and Sirius almost doesn't believe it. He has half of a second to dwell on it, before Kreacher punches himself in the stomach. Punishment.

"Stop that," Sirius demands, and Kreacher's back stiffens. "What do you mean, Regulus is dead?"

Kreacher looks like he's in pain, like every movement he does is painful. Still, he holds up the locket in his hands and Sirius takes it from him. He doesn't understand.

"Master Regulus told Kreacher not to tell anyone. Master Regulus said that anyone who knows is in danger," Kreacher tells Sirius. Sirius averts his eyes from Kreacher and onto the locket, looking at the ornate S on it, in the form of a snake.

He doesn't understand, but he also doesn't particularly care if he's in danger or not.

"Explain," Sirius commands. "Now."

He grips the locket in his hands tight, and he's sure that there's going to be little imprints on his hands from the chain. Still, he doesn't care. He doesn't care about the locket, or about being in any danger. He just cares about what happened to Regulus.

"Master Regulus died to get that locket," Kreacher says, nodding his head towards it. Sirius looks at it again, his breath catching in his mouth. "Master Regulus said that Kreacher must destroy the locket."

Sirius doesn't really understand. He feels like he's missing half of the story. All he knows is that Regulus died for the item that he's holding in his hand, and somehow it's so important that Kreacher, of all people, decided to seek Sirius out. He doesn't need much more explanation, because anger is filling his brain instead of curiosity. Regulus is — Regulus died. Regulus died for this.

Suddenly, the locket feels a lot more heavy.

"Let's destroy it, then."