A/N Spoilers for series 4, particularly "The Lying Detective"... read on at your own risk.
Disclaimer: "Sherlock" and its characters remain the copyright of Steven Moffat and Mark Gatiss (and of course Sir ACD) I'm just borrowing for fun
This is my first go at Sherlock fanfic, please be gentle! :) Massive thanks to my friend PJ for supplying the shove my muse needed... Hope you like it...
Mycroft placed the handset carefully back on the cradle and stared at it for a moment. Not quite in disbelief since he had known deep down that this day would eventually come, but he still felt sick to his very core. This was going to change everything.
He leaned back, took a deep breath and pinched the bridge of his nose as he closed his eyes. He hoped that somehow this would all go away when he opened them again, but that wasn't going to happen. He had to tell Sherlock everything and deal with the consequences later. Eurus had already dealt the first card, using John Watson to get herself close to them. Mycroft would have to act swiftly before she dealt her next card. He was certain that she'd come back to finish off the job she'd started all those years ago, and this time it couldn't be dealt with by sending her away and trying to forget she existed. This was not a game.
Mycroft couldn't help wondering if he could have stopped it all so much sooner if he'd been older when the first signs of Eurus's unstable mind began to manifest themselves...
He'd never forget that afternoon he came home from school and found a line of five teddy bears outside his bedroom door, all minus their heads. The heads were found later that evening laid out in the brand new cot that was waiting for the arrival of their third sibling in a few weeks time. The incident had made him feel very uneasy, but it was simply dismissed as a bit of attention seeking – apparently it was normal for the younger child to feel pushed out when another baby arrived and it would soon pass.
But it didn't pass, and whilst their parents made every effort to include Eurus in baby Sherlock's routines, she just seemed to see it as him being favoured over her. One afternoon, whilst Sherlock was sleeping after his feed, Eurus slipped into the nursery and cut holes in his blanket. Not just hacking away at it in an attempt to destroy it, she cut shapes into it. A cross, a rectangular shape that she later told Mycroft was representing a grave stone and a skull and cross bones. When the nanny came in to check on Sherlock, she found Eurus stabbing at her own wrist with the scissors, trying to get the blood onto the blanket. The nanny's screams alerted the entire household and Eurus was promptly sent away to stay with an aunt in the countryside whilst they decided on their next course of action.
Mycroft moved his hand into his jacket pocket and pulled out his mobile phone. He should call Sherlock. He would probably have heard about John being shot by now, but he wouldn't know the circumstances yet. According to the informant Mycroft spoke to, John was in surgery although his condition was not considered to be serious and he'd be released in a day or so. It wasn't the physical injuries that concerned Mycroft though. John was grieving for his dead wife, and now he also had to deal with the dark secrets of the Holmes family whether he liked it or not.
Doctors and psychologists had all declared that Eurus would "grow out" of this phase given time. It was natural for a child with a high capacity for learning such as her to be curious about things out of the ordinary and perhaps she needed schooling where her brain would be stretched more. Mycroft knew his parents had doubts about that conclusion, after all, he hadn't spent his early childhood pulling the heads off dolls and teddy bears or cutting symbols out of a baby blanket. But they enrolled her in a boarding school near the Sussex coast, one that specialised in Maths and Sciences, and for a while a calm descended on the Holmes household.
Eurus only came home for the long school holidays in the Summer, Christmas and Easter. She seemed to be doing well and any sign of her previous obsession was gone. Mycroft was finding himself being pushed more and more towards a career in politics or the civil service whilst young Sherlock also quickly displayed an above average intelligence and would give Mycroft a run for his money in many games.
The Summer that Mycroft taught Sherlock how to play chess was the last one they all spent together as a complete family. There was always an uneasy tension when Eurus came home, especially when she was around Sherlock. She hated the fact her brothers had their parents attention all year round, and was particularly angry that Sherlock had been bought a puppy the previous year. The dog, Redbeard, had been intended to try and bring Sherlock out of his shell, but it hadn't worked. Sherlock and the dog were inseparable, and other than his chess games with Mycroft, nothing else mattered. Mycroft was certain he'd seen Eurus kick the dog when she thought no-one was looking, and he seemed to avoid going anywhere near her.
It was Mycroft that found the red hairs sprinkled in a trail down the hallway. He followed it, knowing in the pit of his stomach he was likely falling into a trap but continued anyway. He wasn't entirely sure what he was going to find, but he was not prepared for the sight of poor Redbeard laid limp and lifeless on the floor of Sherlock's bedroom with half of his fur cut off. For a moment, he thought the dog was dead but when he gingerly put out a hand to stroke him, Redbeard lifted his head and looked at Mycroft with pleading eyes. "Help me!".
The vet decided it would be kinder to put Redbeard to sleep. He'd been poisoned by something, but only a full autopsy would determine exactly by what. The parents prepared themselves to break the news to Sherlock, knowing how devastated he'd be, but when they returned home they found Eurus at the kitchen table, mixing together a number of different liquids and powders. When asked what she was doing, her reply was "Preparing the next part of the experiment." Mycroft snatched the notebook from the table in front of her and flicked through the pages in horror. Chemistry was not his subject but he recognised the formulas. This was not a school homework project.
"Mother, we have a serious problem. I think you need to check Eurus's bedroom." Mycroft had said, trying to remain calm. He had a fair idea what would be found and expected his sister to go after her mother and try to stop her, but she simply remained at the kitchen table, laughing hysterically. It escalated very quickly from there. After lots of shouting and crying, Eurus was practically dragged out of the house and bundled into their father's car. Left alone, Mycroft ventured into the bedroom to see if his suspicions were correct. The room was covered in discarded notes, photographs, torn up folders and diaries. Mycroft only needed to look at a few to get the gist of what the 'experiment' was. Eurus was planning to kill Sherlock, and she'd tested out the method on Redbeard first.
Mycroft shook his head. That should have been the end of it. Sending Eurus away to a secure facility where she could be rehabilitated was the only thing they could do. Most of the subsequent investigations were kept from the teenage Mycroft and he was urged to focus on his studies. It was only years later that he was able to access all the records. It seemed the initial thought that she had been groomed by an occult group at school was unfounded. She was simply a girl who had become fixated on death and murder, and in particular the death of the baby brother she despised. They had expected her to make a full recovery.
The phone in his hand felt heavy, reminding him that he still needed to call Sherlock. He had rehearsed the speech a thousand times in his head but it never got easier. Sherlock had very little recollection of that part of his childhood, though Mycroft was aware that he did have occasional flashbacks. Fortunately, his brother's drug habit could always be used as an excuse to dismiss any visions he had that verged on the truth. Sherlock had no idea he had a sister, let alone one who had plotted to kill him and that she was responsible for the death of his beloved Redbeard. Where do you even begin telling someone something like that?
The pain in Mycroft's head intensified. There was still more to tell, and it was probably going to be even more devastating for Sherlock.
"She says she's your sister, sir. Should I show her through?" Mycroft simply nodded. He was still in shock. After nearly twenty years, why was Eurus coming to see him? The family had wiped her from their minds years ago, their only connection to her being the monthly payments to keep her at the private hospital where she'd lived since she'd turned 18. They had made it perfectly clear that she would never be welcomed back into their lives, even though Mycroft had not entirely agreed at first. He'd once believed in second chances and that people could change, but his experiences of late in the hidden government had changed his mind. Keeping his sister away from the public was a very good idea and worth every penny his family was paying.
She entered the office and sat down without being invited, though this didn't surprise Mycroft in the slightest. She was a woman now;the girlish pigtails and freckles gone, but there was no doubt that she was a Holmes; the same pale skin and pronounced cheekbones. He offered her a drink; she asked for water. He offered her a cigarette; she refused. Then he waited for her to tell him why she was here.
"I've been asked to leave Castleton and now I need somewhere to stay, just temporarily until Jim gets back."
Two things bothered Mycroft immediately. Why would the hospital ask her to leave? They were paying thousands to keep her there. And who was Jim? She told him that she'd broken their rules, but it would be fine because Jim would look after her now. At this point she slipped off her coat and it became glaringly obvious which rule she'd broken. His sister was approximately six months pregnant if his judgement was correct. He made angry mental notes to lodge an official complaint to the hospital as to how a patient in an all female secure unit had managed to get pregnant.
"It's amazing how easy it is to slip out of places like that. I did it in plain sight every single time – a couple of borrowed nurse's uniforms, a wig I acquired during one of my little trips and voila!... and then Jim helped me a few times. He's such a clever man, Mycroft, and people admire him so much they'll do anything for him... and I mean anything if you catch my drift. He knows what I did when we were children and he said that one day he'd find a way to make sure I was able to finish off my experiment."
Mycroft's internal alarm bells began to ring. He had to find emergency care for her immediately and ensure that this 'Jim', whoever he was, was not able to get to her again. He reached under his desk and pressed the panic button, a signal that alerted his colleagues to the fact he needed urgent help. Someone would be here within 30 seconds, and Eurus would be taken away.
"This... Jim? He's the father of your baby I presume?"
"He said he'd always wanted a little Moriarty to continue the family line..."
Mycroft pressed the panic button again. This was not the first time that name had been heard in his office recently and the thought that this woman in front of him was connected to the man suspected of being responsible for several murders was terrifying. She had a history of being obsessed by death, and he had supposedly told her that he'd help her finish the "experiment". He was relieved when the door burst open and security began to forcibly remove Eurus.
That was the last time he saw her. He had her committed under the mental health act, and to his knowledge had remained at the secure unit ever since. Until now. He took a deep breath and looked at the phone, scrolling down to find Sherlock's number. He was about to press the call button when the final secret he'd been keeping slipped into mind.
"She has to believe the child is dead," Mycroft instructed. "That way, neither she or Moriarty will go looking for him. It's for his own protection, and he'll thank me one day." It was all arranged, the baby would be cared for at an exclusive facility which Mycroft himself would pay for. The Sherrinford Institute was well known within the government and academic circles. The baby would be well cared for and receive the best education the country had to offer. He would know nothing of his family, except the occasional donation from a mysterious uncle who still couldn't quite let go and held on to the hope that one day his nephew would display the intellect of the other Holmes men and take his place in a suitable environment befitting of a Holmes.
Realising that he could not put this off any longer, Mycroft pressed the call button and let it ring. It was answered within three rings.
"Brother dear, I realise that you are waiting for news of John Watson at the moment, but there are things you need to know and you need to know them now." ...