the plan
Regulus
Over the course of his life Regulus and Sirius had had countless conversations about running away, all of them hypothetical, all of them went the same way. Sirius would say that they should run away and would begin planning what their life would be like if they did. When they were younger, they usually would fantasize about running away to live in a cave somewhere, ever since Sirius had gone to Hogwarts though they always ended up running away to the Potter’s. Every single time the conversation would end with Sirius fully convinced they could and should do it, and Regulus reminding him that they couldn’t. They hadn’t had one of those conversations in a long time
Not until just now
Sirius didn’t know it, but last Christmas, not long after Regulus had had to drag Sirius from the kitchen, up the stairs into his bedroom, his skin dripping with blood -courtesy of their loving mother- he had made a promise to himself. He promised himself that the next time Sirius asked him to run away together, he was going to say yes. And he was going to have a plan.
He had no doubt in his mind that Sirius would already have a plan when he asked him, but Sirius was not a strategist, he always got too caught up in the big picture-its why he was so shit at chess. His plan would probably work just fine if it was just Sirius, but if he was going with him, then the plan needed to be intricate and detailed, with no opportunity for their parents to be able to get him back.
When he was first coming up with the plan, he realised very quickly that no matter how protected the Potter’s house would be, the second he got back to Hogwarts they wouldn't be able to protect him anymore. His parents would be able to send him as many letters as they wanted, they could pull him out of school and send him to durmstrang or something if they really wanted, and they would. He knew that. He realised that the only way to do this would be to get rid of his parents
They’d have to kill them
He didn’t really care that his parents would be dead, they never really raised him anyway, that was all Sirius. He only actually cared that it would have to be either him or Sirius that would do it, he could think of a way around that though, if he really tried.
It took him three months, but he finally had a plan. Simply, the plan went like this: Kreacher would have to kill them (unknowingly of course), it would have to happen on the day they went back to school, and they would both have to be in on it.
He knew he couldn’t bring it up to Sirius first, it would have to be Sirius who came to him.
So he waited. He waited another three months. He knew that Sirius was almost 17 and that it was possible it wouldn’t happen but he kept it in the back of his mind anyway, just in case, just in case Sirius decided he needed to get out now, and decided to try one final time to get Regulus to go with him.
That day finally came within the first week of the summer holidays, he was sat in his room doing homework at his desk when Sirius came in. He acted like the idea was impossible and like they could never do it just enough so that Sirius wouldn’t know how much thought he had put into this already but he was so ready. He made Sirius promise to wait until the end of summer, and decided to reveal the plan to him a few days later.
“So we’re going to have to kill them?” he sounded more like he was confirming it rather than concerned about having to kill them, which was good really
“Yeah, I've thought about it and it’s the only way to make sure they can’t try to bring me back after we’ve gone back to school”
“And you’re sure that there’s nothing Dumbledore or the Potter’s would be able to do that doesn’t involve killing our parents?”
“I'm 100% sure. I've tried to ask Dumbledore to get you out so many times before but he’s useless, he doesn’t care about anyone.” he said this so matter of factly that it left no room for Sirius to doubt.
“okay then. I guess we’re gonna kill them”
Regulus knew that he wasn’t going to tell his friends, but he also knew that Sirius would. So, he made him promise that he would only tell James, Remus, and Peter. No one else, and especially not James’ parents. He agreed, nodding and got up to leave the room.