This is a story that just sort of came about while I was playing a game of Cluedo with my family. I may or may not continue it since I have quite a few other stories going on at the moment, either way, don't expect anything for a while. Sorry.

I don't own Sherlock, or John, or Mrs Hudson, or Mycroft, or 221B Baker Street, or any Human Eyeballs (Barring the ones that are part of me). I do own Scarlet. And the general plot line/idea. And a Cluedo set.

SuperminionXD

Chapter 1: Miss Scarlet in the Lounge with the Cluedo Board

"But I still don't understand how you knew the window was open at the time of the crime" John asked as they approached the front door of 221B.

"I didn't 'know', John, I observed" the self-proclaimed consulting detective corrected, he looked for a second like he might continue then seemed to stare at the door knocker with interest.

"What's wrong?" John asked his friend.

"It appears we have a visitor" Sherlock announced.

"Mycroft?" John asked, remembering the last time Sherlock's big brother (In both senses of the phrase) had invited himself in.

"No, someone else" Sherlock replied shortly, John could've sworn he saw a hint of apprehension as his friend flipped the knocker back to its normal position (Balanced to the left) and went inside.

The scene that met John's eyes when he walked into the flat was not at all what he had been expecting.

"Sherlock, there's a girl in our flat" he stated, looking in confusion at the figure sitting in his chair with a game of Cluedo set up on the Coffee table.

"Ten out of ten for observation, John" the girl remarked, John was taken aback by the fact that the girl not only knew his name but from how she spoke seemed to know exactly who he was. Not only that but Sherlock seemed to have developed a sudden and intense interest in a newspaper he had picked up from the side (which also seemed to be upside down, he realised Sherlock probably already knew this so he didn't dare to comment).

"How did you get in here?" John demanded the girl, since Sherlock clearly wasn't going to say anything. The girl promptly ignored him and stared intently at the board game in front of her.

"You're right, Sherl, this game is ridiculous" she commented, absentmindedly trying to choke the red counter with the spanner (Which John hadn't noticed was exactly the right size to hang the figure) "It doesn't account for any variables, why does it have to be one of the people on the board who did it? He could easily have killed himself! Or some other person not in the game could've snuck in and did it. And why are there only that many rooms, what about the bedrooms or the bathroom? And why only use those weapons? Why couldn't they have stabbed him with a billiard stick? Or smothered him with the curtains? Or dropped the piano on him? It doesn't even say how he died! They could've used the lead piping to hit him over the head, or ground it up and put it in some cakes to poison him. And why do they have to be named after colours?"

John was even more taken aback, he was sure he would never think of Cluedo in the same way again.

"You're one to talk" Sherlock snorted without looking up from his paper. The girl glared at him.

"You're no fun!" she complained, "When do we get to go stop people killing other people?"

"Not now" Sherlock replied curtly, still not looking up from his upside-down newspaper.

"Am I missing something?" John asked, "Like why there is a strange girl in our flat and who is she?"

"John, Scarlet." Sherlock introduced, if you could call it that as he still refused to glance up from his paper.

"And you know her how?" John prompted, only to be ignored as Sherlock changed the topic completely.

"You know Mummy hates it when you dress like that" Sherlock reminded the girl, looking up for the first time to eye the girl's odd outfit. She wore a bright red top that stopped just above her bellybutton, a black miniskirt with red under the pleats and a knee-length black trench coat with the sleeves rolled up above her elbows. Red star-shaped earrings hung from her ears.

"What Mummy doesn't know can't hurt her" The girl (Scarlet, John reminded himself) replied immaturely, "Besides, she's always saying I should act like a 'normal teenager'"

"So, wait, she's your…" John started, only for Sherlock to interrupt him, while still glaring at Scarlet.

"Sister" he clarified, still glaring.

"You have a sister?" John exclaimed, now that he looked at her, Scarlet did have quite a few similarities to his friend; they both shared the same hair and eye colour along with the high cheekbones. Though Scarlet did look distinctly different, she was a girl, obviously, and also significantly younger, her black hair was straighter and reached her shoulders where it flicked outwards and there was a bright red streak down one side, by her face.

"Evidently" Sherlock replied, Scarlet glared back at Sherlock for a short while before sticking her tongue out.

"Ok, I give up" she relinquished reluctantly as she pulled down the hem of her top to reveal that it was actually a normal length top rolled up to look like a cropped one. "Better?"

"Much" Sherlock replied coldly, "Now, why are you here?"

"Mummy says I have to try to be normal" Scarlet shrugged, " They tried sending me to school but after I hacked the school computer for the test answers and texted them to all my classmates one by one she thinks I need reforming or something"

"You did what?" John gasped, now seriously worried about the sanity of the entire Holmes family, "Also how does coming here have anything to do with being normal?"

"It was either here or the British Government" she shrugged; John was slightly confused and looked to Sherlock for an explanation.

"Mycroft" Sherlock answered simply before returning to his paper.

"Of course" John said, rolling his eyes, "So, what? She just pops up here and expects to stay?"

Before his question could be answered Mrs Hudson bustled into the flat.

"Ah, Sherlock, I thought I heard you come in, I…" she started, but trailed off when she saw the third figure in the room. "You really should tell me when you have guests"

"Hi Mrs H!" Scarlet chirped, slightly shocking John, he hadn't thought anyone related to Sherlock could possibly be that happy to see someone, or really look happy at all at times that didn't involve murder or some sort of drastic emergency.

"Oh, Scarlet, how nice to see you!" the woman exclaimed, "What brings you to this forsaken flat? Would it kill you two to tidy up once in a while?"

She frowned as she found she had stepped on several papers that had been lying on the floor. Sherlock ignored the comment.

"Perhaps Scarlet would like some Tea?" John suggested, trying to get the topic away from the mess that was their flat. Mrs Hudson huffed at that comment.

"For the last time, I'm your landlady, not your housekeeper!" she snapped, before turning to Scarlet, "Now, Dear, Why don't you come downstairs for that Tea, where there's actually room to move"

"Only if you tell me about that time when you got attacked by those random Chinese ninja guys who thought John was Sherlock again" Scarlet replied with a smirk.

"If I must" Mrs Hudson replied reluctantly, "Now let us girls be off, and I expect this place to be at least presentable when I next come up"

"Of course, Mrs Hudson" John assured the woman as he escorted the pair to the door. He needed to have a serious talk to Sherlock as to whether there were any other family members waiting to crash their flat that he should know about. Knowing Sherlock, the conversation would be rather short and one-sided.

"So, you have a Sister" John repeated, hoping the other man would make some sort of reply rather than staring intently at the still upside-down newspaper. "Any other relatives I should know about?"

"No" Sherlock replied curtly without looking up.

"Would you actually tell me if there were?" John questioned suspiciously, the silence that followed told John all he needed to know. "So, what? We just let her stay? With no warning whatsoever?"

"She can have your room" Sherlock announced.

"And where will I sleep?" John replied, rather annoyed at not being consulted. Would it kill Sherlock to think of someone but himself for once? Sherlock looked up at the recently vacated seat with the Cluedo game set up in front of it; the red counter and the spanner were left on one arm. "The chair… great"

"Glad you approve" Sherlock replied, completely missing the sarcasm in John's voice.

"I'll just move my things then" John announced reluctantly, casting an annoyed glare at his so-called 'best friend'.

"Yes, do that" Sherlock said, placing down his paper and crossing the room to the kitchen. (Possibly to check on the human eyeballs in the fridge he was using to measure the deterioration of the retina after death, or something like that). John sighed and retreated into 'his' room to arrange it for the girl to stay in.

Sometimes John didn't know why he even put up with Sherlock and his dysfunctional relatives.

So… Hope you liked it. Just so you know, I'm NOT putting this story up for adoption, I like it too much for that, it just may take me a while to write more. I do have some sketchy ideas, but I haven't worked out the main plot/case.

Just so you know, this is set during The Reichenbach Fall, Sherlock is famous but the whole thing with Moriarty hasn't happened yet.

Another note, I will not be doing any pairing or romance, especially with Sherlock and John, people might hint it like in the show, but nothing like that will happen. I just don't write romance. Enough said.

Bye for now,

SuperminionXD

P.S. if I do continue, there will be a cover picture so you can see what Scarlet looks like 'till then I'll just leave it to your imaginations (That is if there is more than one of you, or any at all)