Drabble in need of editing that was written in under three hours. TW for non-explicit gore.

Eurus had always been a... Strange child. Though she and Sherlock had always been closer than Mycroft could ever be to either of them, it seemed that Mycroft always ended up worrying the most about the two being in each other's company, despite their obvious similarities. Eurus was interested in chemistry and biology. Sherlock too, had begun to show similar interests, despite not even going to school yet. Both were very smart and had a habit of speaking whatever happened to be on their minds, which was often something not approved of by their parents. And, of course, both had a habit of pissing off Mycroft.

Yet, Eurus was different. Different from the people she knew, different from the people she didn't.

Sherlock was utterly blind, utterly naive, despite being a loving child. He cared deeply for animals, and made sure to dissect and inspect already dead animals, which he suspiciously found quite often. He cared quite a lot about many things, actually, a little bit too much. It wasn't an unusual thing to see him crying, probably over something silly. But the tears usually stopped rolling down his face once someone began to explain to him the science of practically anything.

Eurus, on the other hand, often came back in the house with her hand suspiciously covered in dried blood, her skirts and dresses in mud, mixed with God knows what else. She had a habit of switching emotions quickly and unpredictably. If there was any game that she was to play, it would be Pretend. She masterfully, for an eight year old, took on different personas to go with every character, naming them all after whispers she heard throughout the day, usually from the telly.

Eurus was a violent, deceptive, and worrying. Sherlock was reckless, caring, and curious.

It could go without saying that Siger and Violet Holmes were more than worried about giving their youngest a dog for his birthday. While Sherlock had often been heard blabbing on about how much he loved dogs, not-so-wistfully pointing out all the good things of dogs, and being sure to leave around dog-related items, helpfully hinting that he'd like a dog for his birthday. For a five year old, he really was quite clever. Subtle though? Not really.

Mycroft, however, despised dogs. He thought they were messy creatures, doing little to no good at all to the people around. The responsibility of a dog went unsaid with Sherlock; the boy "forgetting" about having to take the dog out for walks, pick up after the dog, clean any vomit or hairballs it may get, and having to clean up all the hair the dog was to shed. Honestly, Violet couldn't agree with Mycroft more, but her children's happiness always came first.

And Violet's daughter's stance on dogs? Well... She was a violent child.

But, when Sherlock began to pout a little bit after all of his sixth birthday presents had been opened, it was clear that his parents' decision was well worth it; for the time being anyway. For despite receiving many pricey school books and supplies, his expression for all those expensive gifts could have been labeled "depressed" once an Irish setter bounded into the room, excited and young. Sherlock didn't bother to see who had let the dog into the room, he really didn't care.

The young child's face lit up in utter pleasure, jumping up and down, grinning, and laughing as the dog immediately began to lick his face, while Mycroft's face immediately knotted up into a face of displeasure, thinking of all the "presents" he would find around the house now, thinking of everything he had wished to avoid when he had pleaded with his parents to at least pick a dog with a low life span, like a French Mastiff. Instead, they'd picked an Irish Setter, because his parents had insisted on not traumatizing the child with their dog's death.

Eurus looked off to the side, short hair covering her black expression as Sherlock was bombarded with his new dog's love. It seemed that daughter Holmes had some competition.

It's a fine line between "love" and "obsession". Sherlock was walking that fine line with the Irish Setter, of whom he'd affectionately named Redbeard, to go with his great love of pirates. You could not see Sherlock if he was without Redbeard. If you thought you did, you absolutely had to be hallucinating, since something like that wasn't possible.

At the dinner table, if you looked at the right moments, you would see Sherlock feed Redbeard nearly all of his food off his plate. On the way to school, you could see Sherlock knowingly making himself late so that he could try to teach Redbeard to roll over. Inside his room, you could hear Sherlock reading his beloved dog chemistry books, as if they were a fairy tale, not a book that most students would despise. All this did not, however, mean the Eurus was completely erased from Sherlock's life, despite being sawed off from Sherlock's hip. It was brutally painful. Sherlock did not realize or comprehend his sudden disappearance from his sister's life, and his sister could not comprehend why she'd suddenly become such a minor part of her brother's life.

Being isolated from a loved one can take it's toll, and for Eurus, that toll was locking herself in her room and talking to herself in various accents, having various conversations at once. It worried her family quite a bit.

So, when Sherlock and Eurus played Pretend, Eurus' characters seemed to have more depth than ever. It was frightening to Mycroft, adorable to his parents, who seemed rather weak and fragile if Mycroft had to be honest.

With Sherlock's dissections growing less and less frequent, Eurus' dresses became more and more clean. But Eurus felt very, very dirty, deeming the killing of frogs and other amphibians useless if they weren't to be used by Sherlock. But Eurus desperately needed a cleanse; and in order to cleanse yourself, you must take a bath. So, Eurus had to find something to cleanse herself with. Without a word, she slipped away into the nearby forest, grasping something sharp, feeling the hot afternoon sun turn into cold moonlight. She'd splashed around in the river, but the river was dirty. She was only cold and dirty afterward, which was hardly an improvement. But then, she heard the soft sound of footprints in the nearby soft dirt, still damp from yesterday's rain.

She screamed as she sliced open the stomach of the deer with a kitchen knife. The deer falling to the ground with a gasp of pain, but Eurus smiled with delight. As her hands gripped the sides of the slice she'd made, she pulled it open with all her might, red liquid and pink, gushy strings falling out. She pulled nearly everything out of the deer, splashing her face and arms with whatever had been inside the deer as she kneeled in the mess she was making. She giggled as she dropped herself into the pile, finally feeling cleaner than she'd ever felt, rolling around and fighting the urge to cleanse her mouth as well.

This was how her parents found her. Eurus smiling, telling Mummy and Daddy just how clean she felt in the carcass of a dead deer.

After a time period that Sherlock could not calculate, Eurus returned, and a variety of things were removed from the house. Eurus was ten.

She had become an angry child, her conversations with herself becoming angry, her voice bleeding and cracking. Often, Sherlock would run up to her door, asking if Eurus wanted to play Pretend, like they had before. The only thing he received in return was an angry scream and a hard bang against the door, rattling the whole house.

Sherlock didn't ask after that.

After a month, Eurus started coming out of her room again. Her family didn't trust her personality, which was smiley, happy, and carefree. Eurus called it Enola. And Enola really liked the color red. Sherlock hid from her and Mycroft eyed her warily. "Enola" wasn't allowed outside of the house. She wasn't allowed in the kitchen, and she wasn't allowed in anyone's room but her own. Most definitely, she wasn't allowed anywhere near Sherlock's only source of happiness: Redbeard.

Redbeard continued to act like a carefree, bounding puppy, and he truthfully was. Sherlock knew this. Redbeard was only around three or four, Sherlock hadn't bothered to find out which, so Redbeard still had at least a decade. The thought made the youngest Holmes grin toothily, and at the sight of Sherlock's toothy grin, obviously directed at the Irish setter, Enola encountered her first frown.

Within a few days, as expected, Enola disappeared. Eurus instead, decided to cower behind Sherrinford: a boy akin to Sherlock. Eurus had stolen Mycroft's hand-me-downs for Sherlock and had begun to wear them instead of her own clothes. Her already shorn hair helped complete the look, despite being obvious that she was female. Sherlock liked Sherrinford, but not any more than he had Eurus' other personalities. Noticing this quickly, Sherrinford became Mary, who became Marjorie, who became Birdy, and so on, so on. Sherlock, of course, remained oblivious to the cause of Eurus' identity crisis. He was utterly blind, utterly naive.

It was a shame that the boy could be drowned so easily with love.

"Caring," Mycroft often reminded himself when thinking deeply about his siblings, usually Eurus, "Is not an advantage."

When Eurus finally became Eurus again for more than a month, it was a huge relief to her family, who'd been having problems figuring out questions such as, "Is she a she today?", "What's her name today?", "Is she still having the same identity?", and, "Dear God, when does it end?"

It was becoming clear that perhaps their daughter had returned for good this time.

Eurus' hair had grown to the length it had once been, and she'd gained glasses, of which she thoroughly enjoyed the presence of, although it'd been a weighted decision to decide whether or not Eurus was able to go outside to do her check-ups. Obviously, it had been decided that she could. Despite a bit of grinding of teeth, the visits were smooth sailing.

Slowly but surely, the Holmes family began to insert potentially harmful household objects back into the house. The Holmes family was becoming as normal as it could be once again. Mycroft felt comfortable enough to unleash his unrequited sassy attitude, Sherlock felt comfortable enough to play with Eurus again, and their parents felt comfortable enough to arrange their annual trip to France, which they'd missed for the past few years. But Eurus was feeling dirty. Her dresses were always dirty. Always devoid of what could make her feel clean. She'd grown dirtier and dirtier ever since she'd been taken away. When you're dirty, you should always bathe.

But to bathe, one cannot simply run water into a large pot. Water is not cleansing. People drink water, people crap in water. Water is not cleansing, because it is not worth anything. Water is a resource that no one cares about. People do what they want with water.

But blood? Nobody does anything to blood. It is cleansing because blood is held inside, it is kept within people and animals, held closely. Blood is worth something. Blood is what pumps through your veins, blood is what keeps you alive. A little more never hurt. But killing a person, Eurus had learned, was unforgivable. Her brother wouldn't accept her then. And her brother's love was all that mattered. Perhaps he'd grown away from her because she wasn't clean. Dirty people were never liked. But to clean herself, she would have to spill blood. And if she couldn't kill people...

That meant there was only one thing left for her to kill.

The love of Redbeard wasn't real. Redbeard was a dog, and dogs were dumb animals, not capable of sentiment or feeling. Not like Eurus. Eurus' love was real. She was human, and humans were smart, capable of sentiment and feeling. And yet, Sherlock felt sentiment to the dog. The stupid, stupid dog. As such, she could not just slice open it's stomach to cleanse herself. She would simply make several slices in the dog, letting it drip into the bathtub. And so, this is what she did.

And she used a butter knife.

She tossed the dog aside, it's whimpering wails carrying through the halls as Eurus smiled and rolled in the small pile of blood her victim had created. Not as much as the deer, but enough to make her feel clean enough to face her brother. If only she could get that far. Several footprints trampled through the halls at the sound of Redbeard falling. Mycroft could hardly breath, and his parents were stunned, paralyzed, and shocked. Sherlock was sleeping, unaware of the near-murder.

Violet Holmes felt rather like her son's dog.

Eurus grinned at her family, hiding her confusion of their disgust. In her strange accent that belonged to none of the family present in the house, she cried out, "I'm all clean!"

Her smile was long gone when she was taken away again the next evening, not to return. Redbeard had been put down, and Sherlock had retreated back to his room, unaware of what had happened, instead blaming it all on his brother, who gladly took the downfall for his sister's action. His little brother did not need to know that his sister was a murderer.

One Year Later

"Eurus?" asked Sherlock, frowning, the chest which included everything about his sister thrown away and burnt. "I'm afraid I don't know a Eurus."

"East Wind, brother. It destroys anything in it's path, and it happens to like little boys who look just like you."