The Butterfly Effect

Regulus slipped into the Slytherin common room silently, keeping away from the gathered students and padded into his dorm. He returned the invisibility cloak to it's owner, a sixth year Slytherin boy whose name he didn't always remember.

Seating himself on his bed, Regulus laid out the facts in his mind as he'd learned them. Remus and his brother were fairly physical, even if they weren't fucking yet. Sirius was actually serious earlier that day when he'd warned him off joining the Dark Lord. Sirius really did belong in Gryffindor house, and away from number twelve, which was slowly strangling him. Even Regulus could see that, and he did his level best to avoid seeing anything about Sirius.

This left him with a dilemma. He'd promised, to the delight of his mother and pride of his father, to join Voldemort's ranks, and bring honour back to the family name, tarnished by people like his mysterious cousin Andromeda, and his very own brother.

Brother. Regulus flopped back onto his bed, and curled up around his pillow. Sirius was really worried about him, spent time thinking about him. And he changed into a dog. For his werewolf boyfriend. For some reason, this seemed to be the greatest surprise of all. Not that he'd done it for someone else, that he'd done it at all. Animagus transformations were notoriously difficult to accomplish, even as an adult, fully trained wizard, and his brother had done it at fifteen. A sudden swell of pride took him off guard.

That's my brother, he thought, and for the first time in years he wasn't apologizing.

*

Sirius woke the next morning feeling moody and down. Nothing any of his friends did could shake up the funk he seemed to have slipped into, and after breakfast they largely stopped trying. Remus settled down beside him in History of Magic, and nudged a note over to him.

Stop thinking about that letter. There's nothing you can do right now.

Sirius blinked at it, and then glanced at Remus. "Thanks," he whispered, and tucked the note into his pocket. Professor Binns took a headcount, and satisfied that the students were all present, began his lecture on the Goblin War. Sirius settled in to sleep, and Remus dutifully began taking notes.

Sirius opened his eyes to find that he was no longer in the classroom. All around him stretched a great black lake, the water as still and flat as the surface of a mirror.

"Kreacher," a voice croaked from behind him. He whirled. Regulus stood there, doubled over and clutching his stomach as though it pained him. "Kreacher, take the locket. Tell no one what you saw here today. Destroy that locket!"

"Master Regulus!" A wizened old house-elf, one Sirius recognized as the despicable creature aptly named Kreacher. "Kreacher will do as Master Regulus says," the house elf said with servile pride. "Kreacher will tell no one. Kreacher will destroy the locket!"

"Good." Regulus' eyes turned to the lake, which was no longer still and pristine. The water was churning as though whipped by a storm, or by...

Sirius felt nauseous as he realized what was in the lake. Bodies. Thousands of dead bodies were rising up through the water.

Go to a cave.... cross a lake full of inferi... As though he were seeing it again, the anonymous note flashed before his eyes. Barrel full of poison...

The inferi were climbing up over the rocks, pulling, heaving, sagging, and rolling their way towards Regulus. Sirius searched vainly for his wand, but realized with a sudden panic that he didn't have it with him. Inferi were weak against fire, fire would push them back! Summoning everything he had, he tried to cast a fire spell into the Inferi. It was like he didn't exist; the magic, once called, dissipated immediately. "No! Regulus!"

The occupants of the cave ignored him, even as the echoes of his voice were fading. Sirius began moving forward, but it was as though he were wading through pudding. His limbs were slow and unresponsive, and he wasn't going to make it.

Kreacher disapparated with a resounding crack, and Regulus was dragged into the lake by the inferi. Sirius stopped in his tracks and stared at the place where his brother, his only brother, had disappeared beneath the water. The inferi grew still again, returning to their watery homes. The lake grew glassy, and there was no sign or trace that Regulus Black had ever been there.

*

Sirius jerked awake, realized instantly that everyone was looking at him strangely, and immediately leapt to his feet and crossed the classroom in two steps.

Just a dream it was just a dream, nothing more, he's still alive, he's okay...

Regulus had Potions now, in the dungeons, and Sirius took every shortcut he could think of to get there within just a few moments. He burst in through the door, and was once again the center of attention.

Professor Slughorn chuckled madly. "Sirius my boy! How nice to see you. What brings you to our dungeons on this fine day?"

Regulus had turned with the rest of his groupies, Snivellus Snape included, and Sirius simply sagged against the doorway in relief. "Regulus, I'd like to speak to you outside for a moment." He turned his attention to Slughorn. "If that's alright with you, of course, Professor."

"Fine, fine, my boy. Just don't keep him too long. We're working on Amortentia, and I know he'd hate to miss it!" Slughorn gave a jovial laugh, and shoo'd Regulus out. Sirius waited in the hallway while his brother made sure his potion wouldn't melt while he was away.

"What the hell do you want?" Regulus spat, the moment he was out of class. Sirius didn't answer immediately; he simply crossed the space between them and gathered his brother up into a tight embrace.

"I had a horrible dream, Reggie, a horrible dream that you died, you were pulled into the lake by the inferi, and I just had to see, I'm sorry."

Regulus stopped his attempt to struggle free when he heard Sirius' explanation. "Oh." There didn't seem to be much else he could say. Sirius seemed content enough to just hold onto him, and make sure he wasn't at the bottom of an inferius lake, but Regulus wasn't going to just stand there and take it. "Look, Siri, I'm fine. See? Not dead. But I am supposed to be in class. Aren't you in History of Magic right now, too?"

"Yeah." Sirius pulled away, and looked momentarily embarrassed. "I'm sorry for pulling you out of class like that. It was just..."

"Very realistic," they both finished at the same time. Sirius glanced up sharply; there was something in Regulus's tone that didn't quite fit.

"I've got to get back to class. Meet me behind the library when school hours are over," Regulus said quietly, and slipped back into the room behind him.

Sirius, who had only two more periods to do - Potions and the rest of his History of Magic, decided to skive off it, and figure out what 'behind the library' meant to Regulus.

*

Behind the library turned out to be a Slytherin-centric hiding spot, into which someone had dragged chairs and tables, and some wall-posters with famous Slytherins on them. Seating himself on one of the chairs, Sirius settled in to wait.

Almost exactly two hours later, Regulus slipped in from behind the tapestry covering the entrance, and paused. Sirius could see surprise written across his features, and wondered at it. Was he surprised that Sirius had actually shown up?

Silently, Regulus gathered his wits and settled on another chair, leaving a one-chair space between them.

"I had a dream about you, too. The other night." Sirius sucked in a breath, but Regulus held up a quelling hand. "It... terrified me. I dreamt..."

His words trailed off, and Sirius let him arrange his thoughts.

"It was weird," he said finally. "I dreamt that you had gone to kill your friend. The little mousy one, who doesn't belong. Patrick?"

"Peter," Sirius supplied quietly. Regulus nodded.

"Peter. You were going to avenge the deaths of your other friends, um... The Potters. And you did kill Peter. And a dozen muggles. And then you went to Azkaban."

Sirius sat back against the chair, staring off into space. Regulus had dreamed him going to Azkaban for murdering his best friend. Regulus sat quietly for a few moments, and then coughed quietly.

"I'm sorry," he said. "I wasn't going to tell you. And then you came into class today, and said that, and I just... I couldn't not tell you."

"It's alright. Thank you. I'd rather know than not know." Sirius lapsed into silence again, considering what he'd been told. After a few moments of uncomfortable quiet, Regulus coughed again.

"Siri, do you... can you really turn into a dog?"

Sirius blinked up at him. "Who told you that?" He asked mildly, hiding his utter shock rather well, he thought. Maybe there was still time to play it off as a practical joke played on him by someone who didn't like him much.

"No one. I saw you last night with Remus." Regulus's voice was also mild, and Sirius realized that neither of them would do very well hiding things; they were alike enough that anything one did, the other would instantly recognize. Sirius laughed.

"Alright, Reggie, tell me what you were doing out by the Forbidden Forest at nearly midnight last night."

Regulus allowed himself a small smile in return. "I told you. I dreamt of you going to Azkaban. I think, I was just trying to find out whether or not you were still here." Left unsaid was the fact that Sirius had done the same thing - woken up, and gone in search of Regulus. Blood will out, I suppose, Sirius thought, not unkindly.

"And you just..." He trailed off. "I thought I smelled something out of the ordinary. I thought it was just because we were so close to the forest." Now Sirius was amused, shaking off the chill that had accompanied Regulus's description of his dream. "You little wanker! Sneaking around and spying on people in the middle of the night."

"Well, I learned from the best," Regulus shot back, grinning. "Now tell me how you did it. I know why, of course."

"Well, if you must know, it took James and I the better part of three years to manage it. We studied, and took notes, and practiced, and then one day, I blinked and James had turned himself into a dirty great stag."

Both brothers were chuckling at the image by now, and Sirius continued his story. "Well, of course I looked at him, realized he'd done it, and asked, 'Well how the hell did you do that, you great git?' And he looked me dead in the eye, opened his mouth, and made the strangest grunting noise I've ever heard. And then, if that weren't enough, he looked down the end of his snout as though he'd been expecting words!" Sirius was howling with laughter at this point, and even Regulus's normally reserved demeanor had given way to outright laughing.

"So," Sirius said, composing himself only a little. "So I said, come now, change back and tell me again! And then it took him another twenty minutes to figure out the change back. Always said I was the brightest of our group." Sirius looked proud, and fond at the same time. Regulus found himself desperately jealous of James who could produce that look without even being in the same room. "So, he managed to change back, explained to me what he'd done, and then I found myself as a dog. James, of course, immediately suggested I make the change permanent, and then we had to help Peter with his transformation, and you should have seen the look on Remus's face when we showed him what we'd done. We kept it all secret from him, of course, and he about had a heart attack when we told him we were going to go with him the next full moon."

If Regulus had felt a sharp twinge of jealousy at James, it was nothing compared to the almost overwhelming hate he felt for Remus. "So, you've taught inept people before," Regulus said slowly, his mind racing.

"Aye, that's right," Sirius said, looking around the room.

"So you'd have quite an easy time of teaching someone who wasn't inept, wouldn't you?" He prompted. Sirius nodded.

"Reckon so," he added, and focused on Regulus. "Where are you going with this?"

"Siri... Teach me how to become an animagus!" Regulus blurted out suddenly, afraid that if he didn't just get it out and done with, he'd never have the guts to ask again.

Sirius looked compeletely taken off guard by the request. "Alright," he said, surprising even himself. Regulus had been expecting him to say no. "Be here... Saturday. I'll bring my notes, and we can get started. You don't have plans then, do you?"

"Not any more," Regulus said, standing. "Siri... thanks." He acted quickly, before his courage failed him, and hugged his brother. Sirius squeezed him back and let go.

"Get on with you," he said gruffly, already thinking about how he'd manage to teach Regulus in less than a year what had taken himself and James a little less than three to learn for themselves. At least they had all their notes still; Sirius was an avid paper-collector. He never threw anything away, no matter how pointless or stupid, or old, and he still had notes James had passed to him in their first year.

Regulus hurried out of the room, unable to wipe what he knew would look like a shit-eating grin off his face. Behind him, Sirius was grinning too. He'd mended his broken bridges, and even managed to forge a new connection with his brother. Maybe the horrible future from the letter wouldn't come to pass after all.

***
Alright! Another chapter! And still no signs of slowing down. I've had this idea brewing in my mind for WEEKS, but writer's block has all but taken over my mind recently. It's like having creative paralysis, trying to write while sitting on my hands. I promise that this is in the right section. ^_~ It'll be Harry Draco, and we'll even get some sex later on. This is just the build up, the background. (I'm usually not very good at this sort of thing. I tend to jump straight into the action, and end up disappointed with my own work. Unfortunately, while this is a useful tool for teaching myself to be a better writer, you lot get a load of crap in the meantime XDD)

thrnbrooke: haha. telling you that would be cheating. ^_~ You'll find out.
jbj1031965: thanks for your interest! I hope it turns out as good as you think.
Miss Nikki: It'll be Harry/Draco, like I said before. And you'll find out who wrote the note later in the story. And I'm really weird about my pairings, too. I ship Remus and Sirius, and Sirius and Regulus, and Harry and Lucius, and of course, Harry and Draco. XDD

EDIT: I fail. XDD This thing had a few spelling errors, a weird html error, and I'd forgotten most of my comments at the end. What happened, you see, is I was writing up until the point I needed to go to work, and I don't drive, so I was in the middle of making a comment to Miss Nikki, and my girlfriend showed up to get me for work, so as soon as I got home, I just posted the new chapter without reviewing it myself. I started to work on the fourth chapter, and decided to read the story in AFF to make sure it looked alright, and then realized that I had made some mistakes. Sorry about the random edit; I swear it's legit!