So this is just something that's been banging around in my head for a while now. Had to get it out, because I know I'm not the only one who sees the parallels. S4/S9 tag.

He starts out with good intentions.

In hindsight, that's probably what should have stopped him. After all, everyone knows where the road of good intentions leads. And it certainly isn't Heaven. That is his first hint; that, and the fact that he is working with demons.

He starts it in order to save people. That has always been his job, after all, to save people. And this, this is just another way of doing it.

His brother doesn't approve, and makes no secret of it (neither of them ever have when it comes to each other). But something is all cracked and broken between them, and they don't have the trust they once did. And anyway, it isn't like his brother can fully understand the good in it. He isn't the one doing it.

He knows, fundamentally, that it isn't entirely right. It is, however, necessary. And it will only last until she is dead, that she- demon that has been a plague upon their lives for far too long. He is the only one who can kill her, and once he does… then he will stop.

But what he doesn't account for is the addiction. The longer it goes on, the more he wants it… he can't stop thinking about it, and it keeps him up at night, remembering the power in it, the tingling rush in his veins. He can't stop. God help him, he doesn't want to stop.

His brother warns him against it, and although he knows it is out of concern and worry, it comes out as anger and exasperation and disappointment. They fight and argue and walk away hurt, and nothing is better. The silences in the car grow longer and tenser, their strained trust stretched tightly between them. It is only a matter of time before it snaps completely.

When it does, his brother locks him up. "For his own good", apparently, and doesn't he understand that he is doing this for a reason? Doesn't he see that this is the only way?

Despite his arguments and his pleas, his brother closes and locks the door and walks away, leaving him alone and trapped. It isn't long before his body begins rebelling against him, sick and fevered, and he nees it, he needs it.

Eventually, he gets out of that room (or rather, he is let out) with one thing on his mind. He has a job to do. One more thing to kill.

And what's another lie, another betrayal, at this point? It's not his brother's fight, not anymore. He's the only one who can do it, he was always the only one.

But then everything goes terribly, terribly wrong, because nothing is like he thought it was, and all this time he thought he was in control… when really he is completely powerless, and how stupid is he that it took him this long to notice?

His brother is there, seemingly out of nowhere, and he doesn't know why that surprises him, because even after all the angry words hurled between them, his brother still isn't giving up on him. He was the only one who never gave up on him, even after everything. Especially after everything.

It's too late though, because contrary to what he used to believe (when they were kids and it was nighttime and Dad was two states over and they didn't know if it was wind or something much worse rattling at the windows) just because they're together doesn't mean everything is going to be okay. But he lets himself believe, just for a moment, because he's staring the end in the face, and somehow it makes it just a bit better to know that his brother is here with him.

It ends with black eyes and blood at a corrupt convent in Maryland, it ends with black eyes and blood at a secret bunker in Kansas, and it's not really the end but he kind of wishes it was.

He should have seen it coming because his brother was right all along (and he remembers all the times when they were kids when "I told you so!" was a coveted opportunity, and what does that say about them that they're too broken to use it now?)

He should have seen it coming, but he thinks he probably did, and it didn't stop anything because they've been here before and they'll be here again, because a circle has no beginning, and a circle has no end.

Round and round the Winchesters go;

Where they stop, nobody knows…