Come to Baker St. I need you. – SH

John sighed a little at the text. He wanted to ignore Sherlock and continue having a lie in with his wife, but the phone was persistent.

For the safety of Mycroft's life. I need to you. – SH

John tensed a moment, worried, but also wondering if this was another over urgent text from Sherlock that would lead to something as simple him needing a tea and being too lazy to get up and get it himself.

What's happening? – JW

We are having lunch today and I am worried I might kill him. – SH

John laughed and Mary pat him on the chest, having read over her shoulder.

"It's okay John, go play mediator at lunch with the Holmes boys. If it's with Mycroft it will at least be something fancy. Bring me back something posh." She kissed his cheek and struggled to lift her massive pregnant self out of the bed. John hurried to his knees on the bed beside her to help her get to her feet, pausing once she was up to rest his head on her belly and give it a gentle kiss.

"I promise to not let your uncles murder each other today. Don't torture your mum." Mary laughs and tousles his hair.

"Better hurry, the longer you put it off the more he'll make you want to pop him one."

"Very true."

John knocked on the door as he walked in, expecting to see Sherlock agitated and twitching in his chair, maybe taking some of his more violent thoughts about his brother out on his violin, but instead was greeted by the last thing he expected to find on the couch at 221B. A girl. In pajamas.

"H-hello" John sputtered, his face a wash of confusion. She was curled on the far end of the couch from the door, a laptop propped on her knees. Lounging like she didn't have a care in the world in her pink tank top, striped pajama pants and one of Sherlock's dressing gowns. She looked to be in her late twenties maybe 30 if she had taken really good care of herself, with dark red hair pulled into a high ponytail.

Her eyes flicked up nonchalantly. Electric blue/green eyes that seems to be unable to decide which color they were. "Oh, Hi John, love the blog."

John had just opened his mouth to ask the burning question of Who the hell are you? When Sherlock breezed in, dressed in one of his impeccable suits and crossed to the girl. Completely unfazed. "Hello John." He pushed the laptop closed quickly, almost catching her fingers in it. "Go get dressed."

"Jesus, Sherlock! You almost took my fingers off!" John noted that, to add even more to the mystery of this girl, her accent was American with some odd twinge of English under it.

"And you miraculously survived. Go!" Sherlock replied dryly, taking the laptop from her and setting it aside on the desk. She heaved and over dramatic and over acted sigh and uncurled herself from the couch. Stretching up to give Sherlock a kiss on the cheek, making him playfully grimace before she disappeared through the kitchen and back into his bedroom.

John watched the scene with a slightly amused and confused look. Did Sherlock have a girlfriend? Wait, no, he'd seen this already, Sherlock didn't date. The last time it looked like he was dating someone, he proposed so he could get into someone's private office and got shot. Surely this was not happening again.

He finally spoke. "So who does she work for?"

Sherlock was pacing a bit, watching his bedroom door and looking like he was ready to crawl out of his skin. "What?"

"The girl, the girl on your couch, in your dressing gown, now more than likely naked in your bedroom" Sherlock pulled a face. "Who does she work for? The last time you dated a girl, you got shot."

Sherlock looked disgusted. "Oh God, John, I'm not dating her." He paced down to his bedroom door and rapped on it with a touch of irritation. "Do hurry up, while I like to make Mycroft wait, I feel like this is not the best time to get on his nerves."

"Calm down will ya! I'll be out in a bit." She shouted back, the irritation just as clear in her voice.

"Will someone please tell me what is going on?" John finally settled into his chair and waited. Sherlock moved over to fall into his own, drumming his hands on his knees. Distracted.

"What?"

"Who is she Sherlock!?" John finally stopped mincing words.

Just as he was about to answer Sherlock popped up from his chair, hearing the bedroom door open the girl re-emerged in a black cherry print tea dress, black cardigan and red Chuck Taylor shoes, arranging her ponytail into a bun on top of her head. She strolled over to the mirror above the fireplace to put on her lip gloss. Sherlock gave her a quick once over as she walked and shook his head.

"Nope. Shoes. You can't wear sandshoes to lunch. Mycroft is putting on a show and taking us to someplace very pricey and again, while I would love to see his face, today is not the day."

She spun on him with a look that could peel paint. "Stop telling me what to do, Sherlock!" John watched them with utter confusion and then rubbed his face.

"Stop doing things that force me to do so. Shoes. GO."

She heaved another mighty sigh and stormed back to the bedroom "Fine!"

"You're not dating? You two fight like you've been married for twenty years. Shit, she's not secretly your wife is she?" John laughed at the thought but the laughed faded as Sherlock didn't answer. "Sherlock tell me you're not married."

"No John, not married." Sherlock was clearly distracted as the girl came back, having changed into cherry red ballet flats, looking like she could kill him. "There, was that so hard."

"I don't see why my shoes matter that much, but if it makes you happy." She smiled, John noted it was almost like the smile Sherlock would give when he was only smiling because I thought he had to.

He finally snapped and stood, spinning to stare them down. "Will someone PLEASE tell me what is going on here?!"

"John Watson, I'd like you to meet Ainsley Holmes." Sherlock draped an arm over the girl's shoulder. "My little sister."

John shock lasted a bit longer than Sherlock expected. His friend stood staring at them for a solid two minutes, shaking his head and repeatedly opening and then closing his mouth.

Ainsley laughed awkwardly, "I think you broke him."

"You may be right. JOHN!" Sherlock's sudden volume snapped John out of his fish impression. "We have to meet Mycroft for lunch, shall we?"

"Yes, but wait. You have a sister."

Sherlock helped Ainsley into her coat before shrugging on his own. "Yes."

"Sister, like, you have a mother and father and she has the same mother and father." Ainsley laughed a little. Sherlock just shook his head.

"Yes, John, that's typically how it works. Do keep up."

John followed them down the stairs, still completely confused. "But, she's American."

"Not exactly, I can explain tha-." Ainsley started but Sherlock cut her off.

"Later, we're late now."

John acquiesced, "Alright, then, American sister, no big deal, off to lunch."

The closer they got to the restaurant where Mycroft waited for them, the tension in Sherlock deepened. John watched his friend's jaw and fist tense. He knew the brothers didn't always get along, but this seemed like a new level of stress. John was about to ask Sherlock if he was okay when he saw Ainsley rest her hand on her brother's tensed fist and gently say. "It's going to be okay. Don't pick a fight with him. The past is the past La, just let it go. Please."

Sherlock appeared to relax a little, loosening his fist and turning his hand over to hold hers, but clearly couldn't let it go. "It's just hard." He turned to her and gave her a tense, weak smile, clearly trying to make her happy. "I've never forgiven him."

"I haven't either." She replied. A cloud going over her expression before she turned away.

Mycroft was 14 when his parents let him know they were having another baby. He let them know immediately that he felt that was a horrible idea. Look how the other one had turned out.

Sherlock was 7 and a bundle of excitement and worry. Excited to possibly have someone who would want to go on adventures with him, but worried that they would bring home a mini Mycroft. Either way, he just wanted a little brother.

He was mildly disappointed when his mother brought home a girl. A screaming, red faced girl who seemed to never shut up and was perfectly useless as an adventure buddy, but it faded quickly. When his mother lay the tiny thing in his arms, and she stopped screaming, curling against the boy as if she knew he was her family, he fell in love. "I think she'll do, Mum."

Once Ainsley was old enough to walk and talk, Sherlock had a near constant shadow. As time wore on, the fun of being a big brother was starting to wear off a bit.

Sherlock's temperament was always mercurial. He wanted to be able to control it, and knew that the only way he could retain the appearance of an even keel, was to retreat into his own mind when everything got to be too much. That could be a real challenge when one had a little redheaded monster storming to follow when he tried to escape and calm down.

"La, why are you so MAD?" Ainsley's little fists pounded on his door. He clenched his teeth.

"I'm not mad. I am angry. Mad means insane. I am not insane." He repeated the last part quietly to himself. He was 14 now, and he was having a harder and harder time keeping the constant noise in his head organized and quiet. "I'm not mad." He whispered to himself, rubbing his temples and sliding down the door, pressing his back to it.

Ainsley let her head rest of the closed door between her and her brother. "I didn't mean it La, I'm sorry." Even though she was barely seven, she had learned how to calm him, soothe the scary times with her brother. "You're not mad, you're angry. It's okay. I'm sorry."

He slid to one side and cracked the door open, letting the little girl into his room. She curled up next to him and rest her head on his shoulder. "I don't mean to yell at you. It just get so noisy in here sometimes," he tapped his temple and then let his head rest on top of hers. The next came out as barely a whisper. "I heard Mycroft telling Mum and Dad that he thought they should sent me away."

He closed his eyes tighter, the memory replaying with over saturated clarity in his head

Mycroft sat almost inhumanly straight, his hands folded neatly on his lap.

"I'm worried for you and for Ainsley, Mum. He's just getting worse. What if he gets violent? How long will it be before he loses control and hurts you? Hurts her?"

Sherlock's fists balled at his sides as he listened to his brother's overly calm words. He would never hurt his sister, but it was taking a lot of control to not hurt his brother right now.

His mother spoke up, "I don't know if sending him somewhere will help him Myc, you work in that system, you know some of those places," she shook her head, "the things they do there, are almost worse than no help at all."

Mycroft leaned forward, scrubbing his face with his hands. "I know, but there are good facilities, reputable ones. They can help him. It's just, safer."

Sherlock couldn't hear anymore. He knew his brother had always thought he was a mistake. That he thought Sherlock was stupid and damaged, but he never thought he would actually hear his brother tell his parents to get rid of him.

He stormed off, his mind screaming, so loud it hurt.

"Are you okay, La?" The voice was tiny and far out in a sea of noise.

"SHUT UP AINSLEY I NEED TO THINK!" He didn't mean to snap when Ainsley asked him what was wrong, but he couldn't hear himself over the noise.

Now they were on his bedroom floor, and he could feel himself calming a little, tethered to the anchor that was the tiny girl curled against him.

"He think's I'll hurt you." He mumbled softly.

"I know you never would, La. It's okay now."

He never intended for her to get hurt, but control was something he was slowly losing as time passed. He stated to think his brother was right.

"Sherlock!" The voice floated somewhere in the distance, a fluttering ghost of sound on the periphery of his mind. It was growing insistent.

"SHERLOCK!" It was right over him now, shaking the walls around him.

He felt a sharp smack. Mycroft stood over him, shaking his hand and looking down at him. He felt the heat on his cheek.

"Sherlock, where is Ainsley?"

"What?"

Mycroft grabbed his shoulders and gave him a firm shake. "Where is Ainsley?"

Sherlock's senses started to come back into focus. He smelled smoke. What happened?

"She was in the kitchen. Oh God, Mycroft what is happening?"

He didn't get an answer, he just watched his brother run into the house, calling for their sister.

Ainsley was curled in a ball in the corner, squeezing her eyes shut and rocking, talking quietly to herself. "It'll be okay, He didn't mean to, it's okay." Mycroft scooped her into his arms, hugging her tightly to him before setting her down on her feet and turning her left to right, checking her over. The sleeve of her shirt was singed black, burnt and torn away. An angry red burn crawled up the little girl's arm from her wrist to her shoulder. Mycroft sprung to action to tend to the wound.

Sherlock barely saw her, as he followed into the kitchen, still half trapped in his own head. "Is something on fire?"

Mycroft held the little girl to him, whispering. "Jesus, Sherlock, what have you done?"

Sherlock didn't know, all he remembered was working in the kitchen on an experiment. Bunsen burners and questionable chemicals. He wasn't getting the result he wanted to he closed his eyes and scanned his memory for the answer that he knew had to be there, when he opened his eyes his brother was slapping him and screaming.

What Mycroft discovered once his sister and brother were being tended to by medical help and his parents had returned home, was that from all appearances, Sherlock had been working on his experiments, not watching Ainsley, who had been playing under the table while he worked, had knocked over a burner and accidentally caught one of the girl's sleeves on fire. Sherlock had done nothing to help her, trapped in his own mind. This had to stop.

Sherlock spend several weeks in the hospital after that and when he came home. Ainsley was gone.

"Mum, where's Ainsley?" Sherlock asked, feeling a pang of panic in his chest.

"We need to talk Sherlock." She steered him into the parlor, where his brother and father sat waiting.

They had sent her away. His mother didn't want to send him to an institution, she knew that he had not meant to hurt her, but Mycroft was worried that if they didn't either send him or her away, she would be hurt again.

Sherlock didn't understand why his brother hated him so much. Hated him enough to take away the only anchor he had left in the world, but he understood that if she had stayed, he might hurt her again, and that thought killed him.

Ainsley was sent to live with an aunt in America, and Sherlock, never tried to love someone again.

John didn't know what to say, when Sherlock disappeared into his own mind, Ainsley had explained where she had been all this time. She spoke without looking at John, just watched her silent brother stare blankly out the window. When she pushed a strand of hair that had fallen loose behind her ear, he could see the faint pink spider web of a scars up her arm. He recognized the pattern.

"He never meant to hurt me. He's got so much in there, it just, steals him sometimes. You've lived with him, you know. He just gets so lost, and I know it's silly, but I used to think that maybe I could save him. That if I could just anchor him here, and not here." She lightly tapped her temple. "He'd get better, but Mycroft was right. I'd never tell him that," She let out a dark little chuckle, "God, if he even knew I said it he'd never let me live it down, but he was right to convince Mum and Dad to send me away. I know it hurt him that they took me away, but it would have killed him if he hurt me again. He didn't even keep in touch for a long time. Just Mum and Myc, but I always asked about him. Worried about him. Was so proud of him when he came out the other side. I have wanted to come back for so long, but I worried that it would do more harm than good." She finally turned back to John, "Mycroft told me what he did, that you were there. I had to come back. He needs an anchor now."

Ainsley put her head gently on his shoulder, tapping his knee gently and whispered. "You need to come back to us, La, we're here."

Sherlock let out a little hum, and put his hand in hers again. "I'm ready."

"Ainsley, you look –"Mycroft scanned the girl up and down, "lovely."

Ainsley tucked the errant strand behind her ear again. "You look—"she gave Mycroft a similar scan, "old." Sherlock laughed and Mycroft shot him a look that turned the laugh into a cough.

Mycroft's eyes narrowed on his brother. "You're late."

"Talk to your sister, she was the one who refused to get ready."

Mycroft relented, "Well I do suppose that when you haven't seen someone in years, fifteen minutes is not a big deal." He moved forward and in a gesture very unusual to him, gave her a tight hug. John saw Sherlock tense a little when Ainsley's sleeve pulled up and showed more of the angry pink scar. The constant reminder of how he had hurt her. She pulled broke the hug and pulled her sleeve down quickly, Mycroft eyeing her arm, and making her feel self-conscious.

"So—lunch?" John asked, breaking the tension for a moment.

"Yes." Mycroft said after a moment. "We have some things to discuss."

They moved to the table that had been reserved for them and he set straight to business. "So, I assume you will stay with Mother, then."

"No, she's staying with me." Sherlock shook his head at Mycroft as if he said possibly the stupidest thing a human could utter.

"Do you think that's wise?" The genuine concern in Mycroft's voice made both Sherlock and Ainsley ruffle. John knew what he was implying.

"Baker Street is a safe place, Mycroft, if he's really alive, I don't see him bringing the fight there."

Ainsley's brow furrowed, "If who's alive?"

The men ignored her. "It also is unwise to broadcast that there is someone here that Sherlock cares about. That nearly go you killed once John, I don't want my sister in that path."

"He don't get near her." Sherlock added through a tense jaw.

Ainsley snapped a little. "Will SOMEONE please tell me who you are talking about?! Why is it not safe to stay with my brother? Why do you always want to pull us apart?"

Sherlock put a hand on her arm for a moment. "He has a point, but I am not listening to him this time. He's not pulling us apart."

Mycroft pinched the bridge of his nose. "Can the two of you please take a moment to think like two adults and not as sentimental children?"

Sherlock opened his mouth to snap back, but came up with nothing. He was not a man who was sentimental, but even he had to admit that having Ainsley back, made him feel something.

Mycroft continued. "I'm not trying to pull you apart. I just want to make sure that since you are back," he turned to Ainsley, "that you are not a target to get to Sherlock. You shouldn't be here, it's truly not safe and I am sorry that I scared you and made you think you had to come."

Ainsley's tension never eased. She had thought that Mycroft was supportive, that when he had told her about the extreme that Sherlock and gone to, that he had murdered someone, point blank, to save a friend, that he truly wanted her to come and try to help save him. It never crossed her mind that he was telling her this to continue to keep her away. "I'm happy to see you too, Mycroft." Her words dripped with venom. She then turned to Sherlock. "I need to leave now, La."

He nodded, "I need to finish talking to Mycroft. John, can you take her back to Baker Street, please?"

"Sure thing." John stood and offered her his arm. Pushing aside the pang of disappointment that they hadn't even ordered yet. He looked back over this shoulder as he walked her out at the two men staring each other down and felt the overwhelming need to lessen the tension. "I know a better place for lunch anyway."

They walked slowly back to Baker Street with their take away from the small fish and chips shop down the road. Ainsley had not spoken much at all since they have left the boys behind to fight. Thankfully John was used to silent Holmeses. Not that he didn't try.

"So, Ainsley, I have been dying to know since before we left."

She replied with a half hum.

"So, yeah, where did 'La' come from?" He figured there had to be a cute story, and maybe a way to tease Sherlock, in the origin of that pet name.

Her face eased into a smile finally. "It's pretty silly acutally, but, really, what 3 year old can say Sherlock? All I could say was Shala for a long time, and it kind of stuck. Eventually, it just became La"

John chuckled warmly, "What did you call Mycroft?"

She joined in his laughter, "Oh he insisted I learn how to say his full name or nothing at all. I called him 'Him' for a full two years."

"So it was Mum, Dad, ShaLa and Him. Sounds like a good time."

"It was the best."

Sherlock stormed into Baker Street and hour later, looking to all the world like he could tear the world in half with his bare hands and went directly to his bedroom.

John moved to follow and Ainsley shook her head.

"It's been lovely chatting John, but I think I need to talk to him alone if that's okay."

He nodded, "Okay, you have my number if you need anything. Take care."

"I will."

John left quietly.

Ainsley walked down the short hall to his bedroom, knocking lightly on the door.

He opened it let her in without saying a word, walking back to the spot where he had curled on the floor, his back against the wall. She slid down beside him. They sat in silence for several minutes before he carefully took her arm and rolled up her sleeve. She hated that he was going to focus again on the history of their shared pain. "I wasn't your fault; it was just an accident."

He shook his head and didn't say a word. She wasn't sure why but she unbuttoned his cuff and rolled up his sleeve. Tracing a finger over the faint scars of tracks that remained from his lowest point. "It hurt you too."

After another long silence, he finally spoke. "He thinks you should leave. I'm not sure that I don't agree with him."

She swallowed and looked away, fighting the overwhelming urge to cry. She had missed him, she always missed him, and while seeing him now also hurt a bit, seeing the detached and someone empty man he had become, she ached to stay and try to get some of the boy back that she remembered. Even if it was only a sliver.

"I will if you tell me to." She finally managed to strangle out, a tear falling down her cheek.

"Please don't."