Chapter Text
Becoming animagi had been such a James thing to suggest, Sirius thinks, as he’s slowly stirring the stewing kettle. The book he’s holding tells him to maintain a perfectly even pace; 11 stirs clockwise, 16 counter clockwise, 22 clockwise again. Ingenious, needlessly complicated, empathetic. And yet, James is the one who’s getting out of most of these post-dinner potion sessions, as so many of his evenings are taken up by Quidditch practice.
Remus, of course, doesn’t know: he wouldn’t approve, wouldn’t want them to put themselves in harm’s way for him. As if he weren’t totally and completely worth it.
Many evenings, Sirius ends up down here by himself, Peter accompanying Remus to the library, to avoid suspicion (and, Sirius supposes, to study for their upcoming exams). He’s kind of glad Peter is here tonight; it gets boring and a bit lonely in the draughty, abandoned dungeon. Especially now it’s spring, and the daylight hours are long, the weather is warming up, and he’d also rather be on the Quidditch pitch, or even in the library, where at least there’s windows.
‘Ok,’ he says, carefully putting the ladle to the side. ‘So I’ve completed step 728… can you hold the book for a moment while I grab the pufferfish eyes?’
It happens in a flash – Peter’s hand reaches across the cauldron, but he stumbles, and the book begins to fall. Both their hands grasp frantically for it: Sirius catches it just as it hits the potion, quickly drawing it back, but too late to avoid it splattering sticky orange potion all over their hands.
Sirius is suddenly not quite as glad Peter is here tonight.
‘Watch it!’ he sneers. ‘That could have gone so wrong. You better pray that the touch of parchment hasn’t impacted the potion’s integrity, or you’ll be the one starting us back up from step 1.’
Peter stares at him with round, panicked blue eyes. ‘I’m – I’m sorry,’ he stutters, before quickly grabbing a handkerchief, reaching for Sirius’ hands. ‘Here – let me clean us up.’
As soon as their potion-covered hands touch, there’s a flash of light behind Sirius’ eyes, then a feeling as if he’s being sucked down into a whirlpool. He wants to scream, but finds he can’t – wants to look at Peter, to see what’s happening, if he’s feeling this too – if he’s ok, but finds all has gone dark. He feels his feet, firmly rooted to the floor, then the whirlpool drags him under, sucking his soul out through the bottom of his soles, down, down beyond the dungeon.
When he finally manages to pull air into his lungs, he is once again rooted to the floor. But with new feet. Alarm bells start going off in his head, because – these aren’t his feet. How can these simultaneously be his feet, while also clearly... not being his feet?
When he's able to open his eyes again, he finds he’s in front of a mirror. Except, it’s kind of a weird mirror. It has no discernible edges. And there’s something slightly off about his reflection, like it’s flipped. Plus, his body appears weirdly 3D – almost like a fairly solid mirage, rather than a reflection.
Also, he’s never seen a mirror in this room before.
Also, he doesn’t usually have to look up, to meet his reflection’s eyes.
His mirage-reflection is staring back at him with wide eyes. This is not weird, as it’s the expression Sirius knows he’s wearing. But then, his reflection moves his right hand, even though Sirius himself is doing no such thing. He feels it touching his arm, and he realises it’s not his arm at all, in the same way that his feet aren’t his feet.
Actually, come to think of it, everything feels ever so slightly off. He takes a reflexive step back as he’s being touched by this – this clone, this clear manifestation of dark magic.
‘Sirius?’ the imposter asks hesitantly, and there’s something about the way he says his name. Something that makes him feel ever so slightly calmer, even though he can’t quite put his finger on why.
‘Are you – are you…’ the imposter begins, in a slight Scouse lilt, falters, flusters, brings a hand to his mouth.
And it hits Sirius.
It’s Peter.
He looks at his hands, his wrong hands, and yes, he recognises these chewed-down nails. Looks down at his wrong feet, and yes, he knows those trainers. He looks back up into his own eyes.
‘How -’ he starts.
‘Oh my god,’ Peter-Sirius breathes, ‘oh my god, Sirius, I’m so sorry – I’m so sorry.’
Sirius just stares at him, speechless.
‘We’ll fix it -,’ Peter starts, ‘maybe - maybe we just – we just do it again. Dip our fingers in the potion and then bring them together. Would that work?’
Sirius frantically grabs around for the book they’ve been using – An Extensive and Empirical Exploration of the Animagus Evolution – leafing through to the section on ‘Common Mishaps and Misunderstandings’. He begins flipping through frantically when he can't find an answer. Whatever type of Mishap or Misunderstanding theirs it, it's certainly not common.
If any other type of mistake occurs at any stage: Do not drink more of the potion, but also do not make yourself be sick. Do not touch the potion. Instead, seek immediate medical attention.
Sirius shakes his head. ‘We shouldn’t fuck around with the potion any more,’ he says, through gritted teeth. ‘We could end up making things worse for ourselves. We could also ruin two years’ worth of progress.’
Peter puts his head into his (Sirius’) hands. It’s bizarre, watching himself make movements that he knows he would never make.
I really am quite good-looking, he can’t help but think.
‘The book says to seek immediate medical attention, but we obviously can’t do that,’ he says.
Peter shakes his head, a blush high on his (Sirius’) cheeks, ‘We’ll go to the library, we'll find more books, we’ll work it out, we’ll fix it. Or maybe -’ he continues, in an almost pleading tone, ‘maybe it’ll wear off, overnight. Like a Polyjuice potion. Maybe we’ll wake up and be ourselves again.’
But this is no Polyjuice potion; Sirius doesn’t need to have tried Polyjuice to know that. It’s not their own, physical bodies that have changed, it’s their very souls that have been transported.
‘Let’s -’ Sirius says, hesitating. ‘Let’s not panic, ok? We’ll go to the library, see what we can find out. But let’s go to the loos first. I’m going to need a mirror.’
Peter scrunches up his face apologetically.
The toilets in the dungeons are as depressing as anything else down here – dark, damp, only scarcely lit by flickering candles. But they do have a full-length mirror.
Sirius stands before it, now, staring at Peter. He moves his arm, and Peter moves his arm. He scrunches up his face, and Peter scrunches up his face. He runs a hand through his hair, and Peter runs a hand through his hair. Hair that is far too short, by the way.
I can’t let Remus see me like this, he thinks illogically.
‘I’m sorry,’ Peter-Sirius says again.
‘I’m short,’ Sirius responds, devastated. ‘And blonde.’
He’s also tubby. He pokes his finger exploratively into the soft squidge around Peter’s waist. It feels kind of pleasant.
‘Stop,’ Peter-Sirius groans.
‘Sorry,’ Sirius responds, turning away from the mirror. ‘Ok, let’s – let’s take a breath. Ok, so, we’re each other, but that’s fine. Fucking up with the Animagus potion can have terrible consequences – we’ve probably even been lucky.’
He glances sideways at his reflection as he says so, wondering if he believes that.
‘At least we’re alive. At least we’re not... permanently turned into frogspawn.’ He reminds himself as much as he reminds Peter.
He takes another deep breath. ‘Ok – so – we need to figure out what we’re going to do.’
‘I thought we’re – I thought we’re going to the library,’ Peter says hesitantly.
‘We are,’ Sirius emphasises, ‘but first we need to convincingly be each other.’
‘Ok,’ says Peter, taking a deep breath. ‘Ok, well, you probably need to stop sounding so bloody posh, then.’
‘Then maybe you need to stop sounding so bloody Scouse,’ Sirius retorts.
Peter pulls a face. ‘It wasn’t an insult. It’s just, people would think it’s weird for me to sound… like that.’
‘Point taken,’ Sirius nods. He tries to think up some of the things Peter says, that sound funny. ‘Ok… how’s this: Hello. I’m Peter. I fancy a proper scran with me lads, are youse coming?’
Sirius pulls a face. ‘I just feel like I’m taking the piss.’
‘No, that was pretty good,’ Peter nods, ‘I mean, except that’s not how you use ‘scran’. Maybe lay off the slang if you can’t actually use it.’
‘It’s proper baltic out,’ Sirius tries.
‘Yes, ok,’ Peter nods, a tad agitatedly. ‘Ok, how about me? I’m Sirius Black, and I’m just so terribly delighted to hear about that rather splendid idea, old chap.’
Sirius laughs; the sound of Peter’s laugh echoes through the toilets.
‘That was not half bad, but I beg of you to please lay off the slang as well.’
He shoots another look at himself in the mirror. ‘Peter, I swear to god, I haven’t been this short since I was a literal baby.’
‘Sod off,’ Peter responds, immediately. ‘It’s not as if this is any better. What’s one supposed to do with so much – limb?’
‘Yeah, you’re going to have to start moving those slightly more gracefully,’ Sirius says, raising his eyebrows, before adding, suddenly worried: ‘at least, I hope.’
He takes another deep breath. ‘Ok, let’s go to the library. And remember – we can’t tell anyone. If Remus finds out about the Animagus potion, he’ll never let us get back to work on it. He’ll be way too worried that something far worse could happen to us. And… we can’t tell James.’
His heart sinks a little as he says this, because all he wants to do is go running to James and have him make this ok, like he always makes everything ok.
‘He won’t be able to keep his mouth shut, and he’ll accidentally tell Remus. So for now, we tell no one, ok?’
‘Ok,’ Peter nods.
‘Ok then,’ Sirius nods back. ‘Let’s go find out how to solve this tiny little problem.’
‘Actually -’ Peter says, ‘while we’re here – I kind of need a wee.’
Sirius can see his (Peter’s) eyes bulging in the mirror. ‘I beg your unbelievable pardon?’
‘It’s not my fault you didn’t go to the toilet before we went down to work on the potion!’ Peter shrieks defensively.
Sirius pinches the bridge of his nose. ‘Do not.’ He starts. ‘Under any circumstances. Look.’
‘I wasn’t -’ Peter protests.
‘You are not to look down. Promise me.’
Peter raises Sirius’ eyebrows and smiles Sirius’ cheekiest grins. ‘Why? Have you got something to hide?’
Sirius groans.
‘Something you’re embarrassed about?’ Peter nods knowingly.
‘Shut. Up.’ Sirius says. ‘Just promise me you won’t look.’
‘I wasn’t going to look!’ Peter protests, hurrying into a cubicle and locking the door before he can receive any more pushback.
He’s definitely looking, Sirius tells Peter’s reflection, as Peter goes about Sirius’ business.
‘If we don’t – er – sort this in time,’ Peter says, when he comes back out to wash Sirius’ hands, ‘I would appreciate it if you don’t look, either.’
‘Hi!’ Remus greets Sirius in Peter’s body enthusiastically as he walks into the library, ‘good that you could make it after all.’
Then he raises his eyes at Peter-Sirius, surprised. ‘Nice change to see you here as well,’ he says, with a soft smile.
You are Scouse, Sirius reminds himself, before saying: ‘Hi.’
Ok, maybe that hadn’t warranted the reminder.
‘P…Peter and I were just going to -’ Peter starts, and Sirius can tell the effort he is expending to sound appropriately posh. ‘Eh – we were going to look into… some books on…’
‘Care for Magical Creatures,’ Sirius adds quickly – a subject both he and Peter are taking, but Remus is not. ‘We have a joint project to work on.’
Damnit man, you’re Scouse! He shouts at himself.
‘Ok, good luck.’ Remus nods, before looking at Sirius, whose stomach immediately clenches up. ‘Pete, if you’re still around later, we should have a chat about that Charms assignment we were going to work on. I think I’m almost there, but -’ he scrunches up his nose a bit. It’s cute. It must be nice to be in your own body, scrunching up your own cute nose. ‘- but when I use the Scouring charm, I just can’t work out how to get the smell to disappear, as well.’
‘It’s in the way you hold your wand,’ Sirius responds without thinking. ‘I’ve noticed you kind of clench it. You need your grip to be much more relaxed.’
‘Oh -,’ Remus nods, surprised. ‘Ok, I’ll try that. Thanks, Pete.’
‘Ehh – sure,’ Sirius says, ‘let’s, uhm, Sirius, let’s go find that book.’
‘Isn’t the Care of Magical Creatures section the other way?’ Remus shouts after them, and Sirius loosely waves his hand and improvises:
‘Different sort of project.’
‘Oh my god,’ he breathes to Peter, as they duck into an aisle. ‘That was so much harder than I thought it was going to be.’
‘I know,’ Peter looks at him with wide, grey eyes.
‘Ok, we need to focus. We fix this quickly, and all will be fine. They won’t find out. If we fix it… like, right now.’
But their evening passes in increasingly growing frustration. They riffle through books on body transformation, on common potion-mishaps, on the bloody philosophy of the intricacies of the soul. There’s nothing, nothing that will help them.
With every book they discard, Peter’s panic intensifies. ‘There’s no cure,’ he keeps muttering, ‘there’s no cure.’
Sirius can’t afford to go down that path yet. There is a cure. There has to be.
‘It’s fine,’ he snaps at Peter eventually, when he’s started chewing Sirius’ carefully maintained nails. ‘And will you stop doing that? These stumps might look cute on you, but Sirius Black doesn’t bite his nails, ok?’
He’s in the bathroom, staring at one purple and one green toothbrush, facing a debilitating choice. Which one to use? His own? It’s been in his mouth, only. But technically, that’s not his mouth at the moment. So should he use Peter’s? That’s only been in the mouth he’s currently in charge of. But somehow, that feels ickier. Eventually, he sighs and transfigures a clean towel into a third toothbrush, that he uses to brush Peter’s teeth.
He reluctantly takes a shower, trying his best not to look. He can’t resist poking Peter’s tummy just a little bit more. The soft jiggle is quite adorable. He dries off, quickly getting into the pyjamas he’s taken from Peter’s dresser – feeling like a thief. He crosses the dorm room, and gets into his bed.
‘Uhm, Pete?’ James asks, from the bed to his right. ‘Why are you in Sirius’ bed?’
Fuck.
‘Oh – erm,’ he startles – in an unintentionally amazing impersonation of Peter, if he does say so himself – ‘Well… Sirius… and I… were going to have a quick chat – about…’
‘About our Care of Magical Creatures project,’ Peter-Sirius quickly interjects, running out of the bathroom, Sirius’ hair still dripping from the shower. Sirius just knows Peter hasn’t properly deep-conditioned it.
‘That must be a tough project,’ Remus chips in, his brow furrowed. Such a lovely brow, Sirius thinks, and such a luxury, to be able to furrow one’s own. ‘Did they just spring it on you today? So close to exams? That doesn’t seem ethical.’
‘Ah, well, you know professor Kettleburn,’ Sirius improvises, as Peter climbs in next to him, ‘always a scatterbrain.’
It’s not strictly true, but Remus and James don’t know professor Kettleburn, so it doesn’t matter.
‘We’ll just, eh, close these -’ he says to James and Remus, already pulling on the hangings, ‘and use a silencing charm so we don’t keep you up late. Ok! Goodnight!’
He sees Remus sending James a slightly concerned look, before they both mutter a hesitant ‘goodnight.’
‘Silencio,’ Sirius whispers urgently, before turning to Peter. ‘Ok – we need to discuss what we’re going to do if we wake up tomorrow and we’re still… like this.’
‘Cry?’ Peter suggests, ‘panic?’
Sirius chuckles, in spite of himself. ‘Obviously, that’s how we’d start the day. But – then. What’s your schedule for tomorrow? When do you have time to sneak off to the library?’
‘We’ve got History of Magic first thing,’ Peter starts counting on his fingers.
‘Ok -’ Sirius nods, ‘so we can skip that.’
‘No!’ there’s a look of earnest dismay on Sirius’ own face, round eyes and half-open mouth, and he wonders if his facial muscles have ever been used in quite that way before. ‘Exams are coming up so soon. I can’t afford to miss it.’
‘Ok…’ Sirius responds, hesitantly, ‘but that also makes imperative that we switch back. No offence, mate, but I don’t want you sitting my exams.’
Peter looks briefly hurt. Then he shrugs.
‘All the more reason we should go. And remember, Peter is not late to class. And Peter takes notes.’
‘Yes, yes, diligent note-taking,’ Sirius responds, slightly bored, studying Peter’s chewed-down nails.
Peter lets out an exasperated sigh. ‘I really hope I wake up as myself.’
‘Yeah, we agree on that,’ Sirius says, rolling his eyes. ‘Ok – so after History of Magic, I go to Ancient Runes.’ He grins, knowing the next sentence is going to blow poor Peter’s mind. ‘And no, I didn’t do the homework, so you’re just going to have to let Professor Babbling down gently.’
Peter groans. ‘How am I going to get by in Ancient Runes? I don’t know the first thing about it.’
‘I sit next to James,’ Sirius responds, simply. He’d suggest Peter skip the class altogether and work on their little project, but let’s face it, they both know it’s going to come down to Sirius to do so. ‘He’ll help you. Just tell him you’re tired and can’t be bothered today. He’ll understand.’
Peter rolls his eyes. ‘I bet he’s used to it.’
Sirius grins, then pushes on. ‘What about you?’
‘Divination,’ Peter says.
‘So, can I skip that, and go to the library?’
‘No!’ Peter shouts, appalled. ‘No – I need you to hand in my essay, and to -’
‘Take notes,’ they finish the sentence at the same time.
Sirius huffs. ‘Ok. Make sure to give me your essay and your notebook in the morning. So – then it’s lunch, which we’ll spend in the library, and then we’re in Charms. I guess we’ll just spend the whole evening in the library as well, then. And we’ll have to swap wands.’
At this, Peter swallows hard, but nods.
‘Ok – what else do you need to know?’ Sirius quickly continues, trying to brush over how naked he’ll feel without his own wand. ‘Don’t laugh at all of James’ jokes, just the ones that are actually funny. His ego will pop one of these days, otherwise. Take whatever clothes you want from my dresser, but don’t dress stupid.’
‘You think your clothes are stupid?’
‘No, I just think you are the type to match my navy trousers with the maroon shirt, like a numpty.’
‘You shouldn’t be wearing that maroon shirt during the week,’ Peter reminds him, ‘that’s a Quidditch or weekend shirt.’
‘Ok – whatever,’ Sirius sighs, exaggeratedly, ‘so just go classic school uniform, white shirt, black trousers, can’t go wrong. Black shoes, please, with that. Not navy. Moisturise, tomorrow. And for Merlin’s sake, use a drying spell on my hair, it’ll look a mess in the morning if you go to sleep like that.’
‘Oh my god.’ Peter sounds exasperated. ‘Yes Mr Black, I’ll make sure no one needs to forget for a second just how handsome you are.’
‘Good,’ Sirius grins. ‘Just because I’m not in my body doesn’t mean I don’t need it looked after.’
Peter gives a small, sad smile.
‘So is that – is that a plan, then?’ Sirius starts, hesitantly, feeling so out of his depth that the plan may as well be on another planet. ‘I’ll… act out my best… Peter… and we’ll figure this out, tomorrow, yeah?’
Peter nods, looking just as hesitant. ‘Yeah, we’ll figure it out tomorrow.’
Sirius waits a while for Peter to leave his bed, before he remembers.