A/N: So I've always been very curious about exactly what happened when Sirius pulled his deadly prank on Severus, and how the other Marauders handled the aftermath. My girlfriend and I often have headcanon discussions together and this topic came up, and I rather like the ideas we agreed on for how things went around that time. Which, of course, got me wanting to write about it. So here we are. I do hope you'll all enjoy it.

Warnings: Language, eventual Sirius/Remus slash.

Disclaimer: Harry Potter and all of its characters belong to J. K. Rowling. I'm just borrowing them.

"You did what?"

Dead silence follows James' exclamation, and Sirius can do nothing but stare at his best friend for a few moments, perplexed.

He had been under the impression that when he returned to the dormitory he shared with his friends, he would tell James the excellent prank he'd just pulled on old Snivellus and that the Chaser would have a good laugh. He had not expected this reaction. Perhaps James hadn't heard him right.

"I said I've just told Snivelly about the passage under the Willow. How to open it and all. He was being a little git as usual, going on about how he'd get us all expelled once he figured out what we're up to...so I gave him a little 'help'. Doubt he'll get far, but it'd serve him right if he did, the slimy-"

"Sirius, you bloody arse!" James is on his feet now, all color drained from his face. "He'll be killed if he gets into the tunnel! Have you thought of that?"

He stares at James as though he's just grown two extra heads. "So what if he does? I'm sure he'll just run away if he actually gets that far. What is with you, mate?"

James is suddenly buttoning his shirt back up, having been in the process of getting it off when Sirius walked in, though he only gets half the buttons, as his hands are shaking rather badly. He gives up on them as he looks back up at Sirius, a fierce look in his hazel eyes that the Black heir has never seen before. "What's with me? The fact that you are a fucking prat and you've done- bloody hell, Sirius, do you even think about the things you say? You and I both know that Snape won't be able to outrun Moony! Not when he's- fuck, where are my shoes?"

Peter, who's just been sitting on his bed staring at the two of them with a look of wide-eyed fear, immediately jumps up and manages to find James' shoes, bringing them wordlessly to the taller boy, who grabs them with a determined set to his jaw. Not that the determination hides the fear.

"You're overreacting," Sirius says, though a strange, cold feeling is starting to travel up his spine. "And just what d'you think you're doing?"

"I-" There's a pause as James pulls his shoes on, "-am going to go get Snape before any damage can be done. Because the one who's going to get it the most if something does happen will be Remus, and I'll be damned if he gets in trouble because of you."

The words sting more than Sirius would have thought, and before he can make a retort, James is running out of the room and down the staircase. He blinks once, twice, before turning to Peter, who's trembling quite terribly and staring at Sirius, lost.

"What...Sirius, wh-what should we do? I-If James is right, then oughtn't we-"

"I'm not doing anything," he replies curtly, sounding haughty in a way that only a Black could. "If James wants to get his knickers in a twist over nothing, that's his problem, not mine. You do what you like, I'm going to bed."

On any other day, he might've felt guilty for the way he leaves Peter, who's still standing there and looking quite pathetic in his too-small pajamas that make him look fatter than usual. But right now he's too busy ignoring the fact that his best friend is pissed off at him, that perhaps he's right and he's made a terrible mistake. So he stalks off to bed and yanks the curtains shut, laying quietly in the darkness.

He does not sleep.

A couple hours later, Sirius hears noise coming from the entrance to the dormitory and he knows that James is back. His stomach has been tying itself into knots for the past however long he's been gone, but there's no relief to be had, not yet. The gasp he hears that undoubtedly comes from Peter, who obviously hadn't slept either, does not help matters at all.

"James! What happened? Are you okay? Is Snape okay? What's taken you so long to get back?"

There's silence for a couple moments before a 'creak' greets Sirius' ears, and he knows James has probably just sat on his bed. Unable to help himself, he pulls open his curtains and looks over at his best friend. He's the palest Sirius has ever seen him, disheveled, and he looks so bloody exhausted that it's a wonder he's even conscious. But he looks okay, all things considered. Hopefully this is a good sign.

"I'm fine. Snape's fine," he finally says hoarsely, not looking at Peter despite the fact that the shorter boy is eying him anxiously. "He got into the tunnel, I'd only just arrived- if I had shown up any later, he'd..." A visible shudder goes through James' body. "But I got him. Dragged him back out. He saw Moony, though- glimpsed him before I got him out of there. He threatened to go tell everyone, but we ran into Dumbledore near the entrance. Filch got him, I think, I'm not too sure. All I know is that Snape started mouthing off and Dumbledore just took us to his office, sat us down, and had us explain everything."

Sirius' stomach drops at these words. "Snape's convinced we all planned the prank on him, to kill him or something stupid like that, so I told Dumbledore what really happened. Told him Remus had nothing to do with it. He believed me, thank god, and he made Snape swear not to tell anyone about it."

Relief spreads through him when he hears this. Everything's going to be fine; James is okay, Remus isn't going to get in trouble, he didn't hurt anyone, and Snivelly- well, Sirius couldn't care less about him, but there will be other days.

"So I was right in the end, wasn't I?" He startles both James and Peter when he speaks up, an easygoing tone to his voice. "No harm done in the long run, right?"

Incredulity spreads over James' face and for just a second, it seems as if Sirius has struck him speechless. But then- "'No harm done'? Are you mad? Snape knows now, Sirius! He knows, and you should've seen the look on his face- he's going to do everything he can to make Remus' life hell for the next two years. And you have no idea how bloody close it was, how- how close I came to being too late."

"But you weren't-"

"But I could have been!" James yells, and there's so much fear and raw emotion on his face and in his voice that Sirius loses the will to speak. For the first time, it seems to hit him that despite all their bravado, they are, in fact, sixteen-year-old boys. And what James has done, it is generally not something that sixteen-year-old boys ever have to deal with. It occurs to Sirius that James' biggest worries are usually Quidditch matches and how to survive the boredom that is detention. Saving someone's life while risking your own...any normal boy their age would be terrified and shaky and thinking about the harrowing 'what-ifs'.

It occurs to Sirius that it's kind of his fault James has to know what this feels like.

He backpedals, voice growing apologetic. "Look, mate, you're right, I'm sorry. I was a prat, okay? But everything's alright, for the most part, so why don't we just go to sleep? You look dead tired, you know."

James expression doesn't change much- there is no smile, no trace of forgiveness that Sirius can't pretend he wasn't expecting. He looks rather like he wants to hit him. "Bloody right you're a prat," he says, his voice low. "I don't think you realize just how much. But you should save your apologies for Remus- he's the one who's going to have to hear about how close he came to hurting someone when he wakes up tomorrow." There's an edge to his voice, and Sirius feels a strange sort of pain in his stomach, like he's going to be sick.

"James," he begins, attempting to appease him, "I really am-"

"I said save it, Sirius." There's a tone of finality and something like anger, which causes Peter to look from James, to Sirius, to James again nervously. "I'm tired and I'm going to bed. Honestly, I don't feel much like talking to you right now."

The tension is thick and suffocating, which Sirius absently thinks is what a lethifold attack probably feels like, and he simply sits and stares dumbly at James as the Chaser wishes Peter a good night and promptly closes his curtains without any further words to him. This once again leaves the mousy boy staring at Sirius in a worried manner, which the older of the two isn't sure he wants to deal with. He isn't sure he wants to deal with anything right now, because this doesn't feel like a normal row between mates. James has never been this angry at him before.

"Sirius-"

"G'night, Peter," he says, quick to cut the other off. Peter gulps and mumbles good night as well, scurrying off to his bed; he can be pretty thick, but he seems to have caught on to the fact that Sirius wants to be left alone. Thank god for small favors.

Shutting the drapes, Sirius finds himself back in the darkness again, his eyes open as he mulls over the events of the last several hours. He tells himself that things will be better tomorrow, when Remus is back to his usual self. He'll apologize, Remus will understand (he always does), and he'll tell James to calm down and he'll be forgiven. Things will be fine. All he has to do is wait for Remus to talk sense into their best friend.

He repeats this to himself over and over until he falls asleep, but his slumber is far from restful. As a matter of fact, Sirius Black has never slept so badly in his life.

Nor has he ever so dearly wished for it to be morning.