Disclaimer: I don't own a single thing. A.N. This is S4 AU. Very AU. But I hope you'll like my version of things! The deepest thanks to my dearest missmuffin221 for encouraging me to write this, and to Chrwythyn, gem among the gems, for betaing this in a rush. There will be a second part, but honestly I am not sure when. Not quickly anyway. I apologise, but my own plot bunny wouldn't rest.

On the proper care of pets

Eurus stretched and adjusted her hair, in preparation for her next patient. How surprised would their brothers be to find her working for Queen and country…well…sort of. Honestly, she'd always been so misunderstood. She wasn't exactly evil. She was simply undertrained.

The scenario is this: you have some, well, let's call things their name, supernatural powers. Which apparently manifested strictly in the female line, so her brothers never had to deal with them. Your mum – the one who *might* have an idea what's going on – refuses to explain because she threw away all that silliness to devote herself entirely to the goddess Science. Of course you're bound to mess up along the way once or twice.

But she'd never meant to hurt anyone. And honestly, she hadn't meant to spirit Victor away! She wasn't sure even now exactly where she sent him, might be Timbuktu, might be the Himalayas. She just wanted him to stop hogging all her favourite brother's time. She felt sure though – the way knowledge came to her sometimes, without actual 'evidence' – that he was still alive. If she'd murdered anyone – even accidentally, by misplacing him into a volcano or in a minefield – the spiritual backlash would be violent and unmistakable.

So no, she wasn't going to let herself be whisked away to…Alcatraz, or whatever its name was. It was surprising how honed her powers became when survival was at stake. She'd die in there, and die insane, but then again, how could she expect uncle to understand, he was a man. And on dad's side to boot.

Escaping – and making a new identity for herself – had been relatively easy. It was a pity that she couldn't keep in contact with her family anymore, at the very least not in person. Of course, she had her ways of keeping tabs on them. But she needed a life. A job. And turning to the exploitation of her powers didn't appeal to her. At least not in the classic I'll read your tarots way.

Above everything – that was something she had in common with Sherlock, she supposed – she wanted to help. And with her ability to influence people, if she put her mind to it (and with a bit of extra help, fine), a career in psychology had seemed the most obvious path. Before she realised what happened, she was enlisted to help with the veterans. Serving someone who served the country, so to speak. Not that she complained. Too many couldn't adapt back, once home. Eurus prided herself in not having lost even one of them to self-destruction, despite the depressing statistics for the category.

And here he was, her next patient. The file said John Watson. Captain John Watson. Doctor John Watson. Shot in the line of duty, and so on. What the file didn't say, the man's aura, grey and dull like pent-up smoke, told her. This man was vanishing, right in front of her. His soul consumed itself with guilt and self-recrimination.

Eurus tried to establish a conversation. To make him say something…anything that wasn't a platitude about the weather. But Watson was damn stubborn. He didn't trust her, obviously. She was a stranger, and he patently assumed she didn't care at all, as long as the government kept paying for his sessions. If she'd told him that she honestly wanted to help him, the man wouldn't have believed her. She'd bet that he didn't feel very worthy of being helped in the first place.

Well, there was one thing she could suggest. If he wouldn't talk to her about his life, he could talk to someone else – anyone else, really, as long as he stopped playing armadillo. A blog seemed like a sound idea. Shout into the void…and before you know, you'll find someone who understands. That's how it'd been for her, when she'd been a fugitive with a rather vague idea of what she could do. True, you met assholes too…but Captain Watson was more than equipped to deal with being hated. It was all the rest of normal life that might prove a challenge.

He agreed with a nod. Taught better than to openly oppose people of authority. He wouldn't retort that her plan was shit, even if he thought so. But he would ignore her prompt. Of course he would. Why should he bother? It wasn't like he would ever be better. She smiled at herself, saying goodbye to him. He would try to ignore her… but she had her trump card.

A day later, John Watson was sitting in his dismal bedsit, staring at the computer that was one of his few worldly possessions. The soldier in him was used to taking orders without questioning them. The doctor knew that following a specialist's suggestions – or at least attempting to – was a patient's duty. Why would they even go to a doctor otherwise?

He'd gone as far to make a profile and fill the required fields for a blog on a free website. That should count for something, right? Actually writing or – worse – publishing, though…that was another kettle of fish. Sharing what? His experiences? His feelings, God forbid? Why would he? At best, no one would care, and his posts would die the death of all ignored blog posts. At worst, some idiot would smell out the weakness in him and start harassing him.

Maybe that was what his shrink hoped? Did she know that he was contrary enough to survive the emptiness of his existence just because some idiot was sending him death threats? The Watsons were experts at self-destroying, just ask his dad or Harry, but they were stubborn enough to stick to their guns until they proved their bullies wrong.

The idea brought a lopsided smile to his lips. Writing "I'd be very grateful if you might send me anon hate," would make for a weird post for sure, but he doubted that his therapist would appreciate that much. In the end, he decided to close the pc. He would have time to write a post tomorrow. Or the day after. Or…eventually. He'd made the first step. Surely that was enough.

Before he could close the window on his computer screen, a sharp nip on his leg distracted him. Grumbling, "A bloody rat problem; just what this bloody bedsit needed," John looked down to find the pest.

What he saw made him rub his eyes, and look again. Nope. Still there. So, okay, he *might* have had a drink. It wasn't like there was much else to do. But it was just the one – not enough to make him hallucinate, surely?

Another bite confirmed that no, the critter was definitely not in his imagination. This still didn't explain how it got in. If he'd got a pet bunny, he would remember it…Especially if the beige ball of fluff (why was everything shit-coloured in his new life?) sported fangs rather than his usual teeth – as if normal bunnies weren't bitey enough – and an even more incongruous pair of both wings and deer antlers.

Ok, breathe. It had to be someone's pet. Maybe a child in his condo had decided that she was in a Halloween mood, despite the holiday being one month and half ago, and dressed up her pet? Though he didn't see any immediate glue or harness, but it had to be there. Simply put, rabbits did not grow wings. Much less 'horns' unless ill, and even then, they didn't look like that.

Well, rabbits didn't do a good many things – one of them was appear in locked houses. The war had left John a bit paranoid (he could admit that) and there was no way that he'd left the front door open. True, the window was open – the bedsit was small and suffocating enough even that way – but a rabbit was no cat. And these wings couldn't be functional, could they? Besides, he'd have noticed the critter if it flew inside, no matter how numbed he was. Unless the fanged, winged bunny could sometimes become invisible too…

And he was back to the hallucination theory. Could this really be a byproduct of his own fucked up brain? At least the nightmares about Afghanistan made sense…Why would he invent such an absurd creature? Distracting himself from an annoying chore surely didn't need such flights of fancy?

The bunny jumped on his lap, eliciting a small oof from him. It looked like a weird ball of fluff, but it was a surprisingly heavy ball of fluff. If it was a mind trip (but he hadn't taken any drugs, had he? so why would this happen) it was an extremely detailed one, all senses involved. Maybe all he needed was a padded cell.

The prospect made him shiver and pet the thing instinctively, seeking to comfort himself. Instead, the damn thing bit him. Again. It didn't foam at the mouth or have other symptoms to make him suspect it might have contracted rabies (small consolation for one's delusion) but it did turn his head, to get at his fingers, in a way that no living creature should be able to do. It figured that even his fluffiest visions would be spooky bastards.

It hadn't broken the skin, at least, but still John waved his hand to chase the sting away…and at the same time, the bunny from hell hit the table and – almost – his keyboard with a powerful back kick.

"Shoo," he growled, "you'll break it." If rabbits could give pointed looks, this one surely was giving him one – and judging him, too. "Wait, are you – giving hints? Do you want me to write the damn blog?" John said. Oh, perfect. Now he was talking to his delusions.

The…thing flew (functional wings, then) over his bed, made itself comfortable, and kept staring at him expectantly. If this was his brain's way of telling him to get down and fucking write, his brain was weirder than he'd always thought.

Angrily, he punched Nothing in the title section. He wasn't going to write a post about 'I have visions of winged rabbits'. Maybe it would be best for him, but he wasn't looking forward to being committed. The bunny still stared. Defiantly, John wrote Nothing again in the body of the post and hit publish. His madness could make him write, but it couldn't make him share. At next glance, the creature had disappeared. Thank God.

If John had hoped that his hallucination would be a one-off, he was disappointed. It didn't matter if he didn't touch a drop of alcohol anymore, if he tried sleeping better in case it was a brain misfire from lack of sleep, or how regulated (boring) his life became.

Every now and then, Fluffy (that was the nickname he'd given to the thing, despite its biting habit and grouchy general attitude) would reappear and not give him peace until he'd posted something. A word was enough, at the start. After a while, it would require more.

John…had an odd relationship with it. On one side, he hated how his brain could produce such an odd concoction…and a demanding one to boot. On the other, he would spend all his time looking up cat videos without the frustratingly annoying reminder of his duties. The one duty he still had, after losing every role he ever held.

Besides, despite looking like a judgmental chimaera almost all the time, Fluffy was…a bit cute. And as long as he still used one hand (fine, one finger, but he wasn't great with tech) to write, the bunny didn't actually mind if he buried the other in its soft fur, or tickled the outer feathers of its incongruous wings. When its fangs weren't nipping at you, they gave it almost a silly air.

The doctor had expected his visions to disappear with the rest of his psychosomatic symptoms, once Hurricane Sherlock took over his life. He didn't wallow in self-pity or stare too long at his gun anymore (no time for it, when he needed to ensure that his flatmate's recklessness didn't kill them all). So why would Fluffy haunt him still? Where had he seen a wolpertinger's image (that's what this particular chimaera was called – after a 'visit' too many by the creature he'd given up and googled it) and why had it seared itself into his brain so deeply?

Honestly, he was scared that the consulting detective would realise he was as insane as a whole army of hatters, but at least his one remaining symptom was oddly limited and didn't seem to endanger anyone. Just, if he went too long without updating the blog (because he was busy, lazy, because they worked for Mycroft and he would be flayed if he revealed any details) Fluffy – or should he call the critter Wolpy? ..No, that was ugly, Fluffy it was – would come back to haunt him and oversee that he did his homework. John was very careful not to acknowledge it or interact with it anymore, not even if he was alone. After all, his flatmate was everything but a fan of consistent, predictable routine, and could pop in any second (or not at all for 3 days). He missed the softness of its fur, though, and then scolded himself harshly for it. This had to cease. He was too scared of the consequences to mention it to his therapist, though.

Then that day…well, night ... came. They had a difficult case for a week – a good 7 and half, according to the sleuth – and they were both knackered. John crashed, falling on his bed still half-dressed, and he fully expected his friend to do the same. Instead, he was woken not long after by a violin melody, and a haunting one at that. That was it. He galloped downstairs, determined to send his insane flatmate to sleep by bodily dragging him to the bedroom if necessary. (And damn his lizard brain for suggesting things like co-sleeping – to ensure that Sherlock stayed in bed – and then…well, being so quick to develop that scenario that he wasn't just red in anger by the time he arrived downstairs).

He was ready to yell, when a look made him snap his mouth closed. Sherlock was playing his violin, bathed in moonlight, like an ethereal vision…and, well, not Fluffy – since his coat shone a midnight blue – but at the very least his first cousin. The wolpertinger sat on the coffee table and stared at the musician with the judgmental air John knew so well.

Sherlock blinked at his noisy entrance. "Oh…sorry, did we wake you up? I didn't mean to, but I have to keep in exercise with my tunes, you see…" he said softly, nodding vaguely towards the creature from hell.

"Wait, you…you see it too?" John remarked hoarsely.

"See it? Of course I see it. And if I didn't, I would feel it soon. He doesn't like to be ignored, though there are ways to bargain with him. My sister is supposed to be dead, but apparently her favourite pet still cares enough to make sure I practice regularly. She taught me to play, you see, and she would sic him on me anytime I was too lazy to repeat my scales and arpeggios," the sleuth explained, shrugging.

Midnight (John's christening originality wasn't the best, but he was truly knackered) had stopped glaring and jumped down the table first and then flew out the window, apparently having decided that getting his pupil to practice more was a lost cause.

"I'll need to hear more about it, but – in the morning," the blogger remarked with a huge yawn.

Sherlock waved, mumbled another, "Sorry," then lay his violin on the table and shuffled back to his own bedroom. Bless John for saving him from another hour of practice at least.

The following day (more afternoon than morning) they both woke up, finally refreshed, and – after a hearty breakfast and lots of coffee courtesy of Mrs. Hudson, "just this once" of course – John started the conversation again. "So, you said yesterday that you can bargain with the…creature?"

The detective nodded. "The breed is intelligent. More than Anderson, I'll bet. They definitely understand human language. You can ask for a reprieve, if you motivate it. I'm on a case, this experiment is time sensitive, it's my turn to bring Mummy to the musicals tonight. He'll disappear, but he'll be back, always, – bigger and hungrier, and determined to keep you pinned to your task for longer. And once, the first time it came back after my sister…well, I'd spent a whole year without being able to touch my violin. Apparently he had formed a family, because there was a whole nest of them, a beige partner and so many kittens …and they all wanted me to play something specific, for some reason. Since then, I try not to let more than a few months at most pass without playing, no matter how tired I am, lest they keep me at it for ten hours," he said matter-of-factly.

The first sentence ripped a chuckle out of the doctor, but then he quieted and listened intently to the story. He would have thought his friend under some drugs' effect, if he hadn't been haunted himself. "Duly noted. Thank you. Any treat they like? I would love to be in their good books, maybe they'll feel less like taking a bite out of me." Faced with Sherlock's puzzled stare, he shrugged. "Never mind. As if you would keep track of anyone's food, when you can't be harassed to eat your own."

"I have a question too. I didn't mention it before because, well, it seemed as if it could sound a bit not good, and I would have sworn Mycroft should have taken care of that already anyway, but…can I meet your therapist? They are the one insisting you blog, and I've never seen anyone else having the same pet as my sister's, much less training them the same way. She said she found it in the garden and…I'm not sure why nobody questioned her, she was great at having her way," the detective queried.

"Well, that seems definitely like a genetic trait," John quipped, smiling at him. "But…sure. Please don't deduce her to an inch of her life though, she might have been slightly mistaken on my diagnosis, but the blog brings you cases, so that was at least a decent idea."

"I'll try. I didn't know your therapist was a lady," Sherlock said, frowning slightly. Then he deliberately relaxed his face, joking, "how is it that you haven't dated her yet?"

"I do have some measure of ethics, you know. And I have enough self-preservation to not like going after impossible things," his blogger replied. Not enough not to yearn after them, true, but with Sherlock in the flat, his therapist was as good as invisible.

Eurus wasn't keeping track continually of everyone under her care – she wasn't Mycroft, thank you very much – but she still was sensitive, and alert to people seeking her out. A soul thread vibrated, warning her of a prompt visit. Oh well. She hadn't encouraged it, not openly, but she didn't mind a reunion. Sherlock was a nice brother. Too nice for his own good sometimes. Maybe he would talk to Mycroft and point out that she didn't need to be jailed anymore.

She had a recompense ready for him. She tried to give them some hints, sending, of all her wolpertinger herd, the mate of her brother's overseer to deal with Watson. A witch felt these things – soulmates, affinities in general… But since Sherlock refused to get the clue, well, that meant that she needed to give a more energetic push. She wanted her brother happy, after all. Time to bake.