Mycroft had been taking care of and protecting the human for most of its life. Its mother had asked Mycroft to keep the four year old alive for many years in return for some very valuable information. Now, he surmised the human barely knew it was human, even when it had been – alive – for twenty-six years now; Mycroft had raised it to believe that it was a "super extraordinary and experimental" type of android, almost like Mycroft himself was. To add to this fact, Mycroft gave the human a nicely-made android name. Sherlock.
Much to Mycroft's pleasure, Sherlock functioned as close as possible to an android – it was easy to pass off Sherlock sleeping as much needed recharging, and the stomach growls could be warnings to be checked for mechanical problems. But if anyone caught it eating or excreting waste, their charade would be over. Mycroft would be taken from his position of power and Sherlock would most likely be executed publicly (as its mother had, but Mycroft never mentioned that fact to Sherlock, nor did anyone else know that it had a child who was still very much alive.)
Sometimes Mycroft wondered why he had never turned Sherlock in after its mother had been executed, but then he reminded himself that, if nothing else, he was a machine of his word. Of course, when Sherlock started to trade drugs, Mycroft had come very close to turning it in; instead, they moved to London and Sherlock was decidedly kept away from drugs. Though, in a completely impromptu conversation, it confided in Mycroft that it wished it could experience the euphoria androids felt when high. All human drugs and alcohol had been effectively destroyed when the androids took over as it made it much easier to pick out the ones suffering from withdrawal. Within years, however, rebel androids concocted and programed their own types of drugs and alcohol.
Now, Sherlock had its own flat in the middle of London, which made Mycroft only the slightest bit nervous and worried. Its land lady was nice and all, a little airheaded in Mycroft's opinion, but it only made it that much easier to keep being human a secret. The only real problem with that flat was that Sherlock insisted on paying for it all by itself, but the thing couldn't hold down a job – which in a twisted way helped by limiting android contact, but still was not profitable towards society – and no one wanted to be its flatmate – which was also very helpful in Mycroft's opinion. Sherlock didn't very much like androids, a probable side effect of being human, and he had a habit of overanalyzing and deducing that just downright annoyed everyone, expect for Mycroft as Sherlock had picked up the habit from him. He also like to solve murders, which meant android parts were strewn about his flat – just the entire place was horribly messy, really – and, during certain cases, it's been faced with the possibility of being killed.
Of course, this is when a poor model of android named John Watson appears. John specialized in repairs and had gone to war against one of the last remaining human pockets. John also missed the battlefield and working with Sherlock filled that hole. From shooting and killing an android that was having others consume a poison – a poison that, frankly wouldn't have worked on Sherlock – because Sherlock had been about to consume it, to getting involved with the Chinese mafia (who ran a creepily exclusive circus) and almost having a date die, to playing a vastly terrifying "game" – a game in which John had been strapped to a bomb - against a national security threat by the name of Moriarty, John was hooked on the excitement that was called Sherlock. It seemed as if that this life of investigating and tracking down murderers was like an extremely peculiar drug that affected both humans and androids alike; though perhaps that "high" feeling was adrenaline, synthetic or not – or, possibly, dopamine.
They had been living together for a year now and John had yet to catch onto the fact that Sherlock was not a "he," but an "it." Every time Mycroft held a conversation with John, the urge to point this out was strong, but was heavily pushed down as the results would be disastrous. But as Sherlock and John grew closer and closer together to the point where John considered it to be his best friend, John could no longer deny the very bizarre oddities that Sherlock embodied.
Mycroft became increasingly worried and, much to his unconcealed horror, realized that he had become fond of his human charge. If Sherlock were to be executed, he would feel sorrow and a sense of loss, and that truly upset and unsettled Mycroft to his metal core. What hurt worse was that Sherlock clearly liked and cared about John – if John turned on Sherlock, it would feel betrayed and that was an emotion Mycroft wanted it to never experience.
And so, even if Moriarty was a greater threat to society, Mycroft concerned himself with watching over Sherlock with more intensity than when it was a child.
Irene Adler was a wild card Mycroft had not been expecting, however. She was toying with Sherlock's nearly obvious human reactions, while having her own more robotic ones indiscreetly being pushed to the back of her drive. Mycroft was merely thankful for Sherlock having enough sense of his boring human mind to fight those inane feelings and get the case done. John was left even more confused – Irene Adler had been a prime android, perfect for forming a mechanical bond with, and Sherlock had tossed her aside all for the sake of a perfectly solved and accomplished case. He had a hard time believing anyone could possibly be that much of a calculator, meaning functioning exactly as he was programmed to. In the past, sure, not running as programmed to would be a problem, but the humans and their "morals" were long over and done with. So why couldn't Sherlock let go of parts of his coding, throw caution to the wind, and take Irene Adler out on a date? He was definitely a newer model, he totally could do it - as John suggested - but he doesn't.
Mycroft is grateful for this. Yet, there is a small, nearly microscopic, part of his wired brain that has him saddened over the fact that Sherlock won't find "true happiness" in someone else. It's a silly thought because humans don't deserve happiness, but Mycroft thinks it anyway.
Then, Baskerville becomes a mystery to John. Landmines, dating back to the first of the wars, releasing a gas that acts as a hallucinatory drug only for androids are the problem which Sherlock solves. But Sherlock isn't affected by the gas and John notices, much to Mycroft's anxiety. Not to mention, it was a human in Britain that set the entire case up – a dumb ex-American to boot. Sherlock brushed off being unaffected as just simply being smarter and more advanced than the old androids the landmines had been designed for and Mycroft wonders if that is truly what it believes, or if it remembers that it's human and simply chooses to ignore the fact. Either way, Sherlock does not completely derail John's train of thought. Doubt is still heavily present in his mind.
In the past, if the neighbors started to suspect Sherlock was anything other than a perfect little android, Mycroft would relocate their place of living or have the neighbors in question done away with. The same cannot be done with John. For the first time ever, things weren't easy – in fact, they were extremely and undeniably hard. And Mycroft hated the feeling of helplessness with a hint of unease and a tainting of fear. Fear is the worst – it could consume a man and do the same to even the most advanced of androids.
The concept of fate was a stupid one; life was a trivial idea that humans were not worthy of; Murphy's Law was a hypothesis that held no proof behind it. For this moment, however, Mycroft believed in every single phrase, notion, and theory the human race had the capacity in their inferior minds to imagine, invent, and create. Fate was unavoidable, life was a bitch, and everything that could possibly go wrong will go wrong.
Moriarty was a fantastic gardener. He planted a seed of doubt in each and every mechanical mind in the nation that Sherlock was not the mighty android that he seemed. He sewed together an artfully fabricated story in which he portrayed the victim. He claimed Sherlock conducted illegal reprogramming upon himself to improve his analytical skills for the sole purpose of having even the queen herself believe that he was more than just the average Quality 1.2 android he was – a boring, inexpensive, and worker type. He also issued a statement saying that to better his understanding of the inner workings of every model, Sherlock conducted murders and experiments to find and discover little wonders and quirks that he could use to his advantage of bettering himself.
If there were to be anything that most bionic people of the world hated as much – or maybe even more – than humans, it would be selfish androids. Selfishness does not further society, nor help it in anyway.
Sherlock became a complete outcast overnight; for the first time in its life, it began to fear for its life. Mycroft feared just as much.
But, for some exponentially unusual reason, John Watson stayed by Sherlock's side.
And yet, as this insane case continued on, Mycroft became increasingly aware that he could not understand the patterns in which Moriarty's wiring functioned – it was as if he was several different androids at once. It unnerved him – who takes two androids in love and convinces them that the other is dead to the point where they contemplate suicide? And why base an almost suicidal-homicide of an archaic, dull, human tragedy anyway? Who breaks open the written android rules just to write "Bring Sherlock" on them and put them back nicely? Who goes on to convince people that Sherlock forced him to do all these things with the threat of his life? Either Moriarty literally had screws lose, or he himself had done illegal reprogramming in able to compute like a human.
When it came down to the final stand, John Watson received a phone call. Mycroft felt jealous – he had been the one there for most of Sherlock's life, but John was the one to get the call? But, Mycroft could still read Sherlock's lips from where he was – in the building across from where Sherlock stood. Moriarty had dislocated his chips and effectively crushed them with a bullet – simply, the machine had been centuries old. Still, this did not change the fact that he had Sherlock standing inches from certain death.
Mycroft hopes that twenty-three years was plenty for the boy's mother – otherwise, he failed and, even if he didn't, he feels that twenty-three was not nearly long enough. Mycroft has failed Sherlock.
"I'm a fake," it told John. "But not in the way you think." John says something before it continues on. "Tell everyone who will listen that I'm a fake. That the newspapers were right. That this was all for bettering myself. I'm selfish." Sherlock pauses. "Stay exactly where you are, John, please, I don't want – I don't – just keep your eyes on me, please." John says something else and Mycroft wants to cry. "This phone call is… it's my note, John. Don't people usually leave a note?" People. No one used that word anymore. Mycroft has to look away now – he won't see it, he can't.
When he hears John scream for Sherlock, he knows what has been done. And when he hears a woman's terrified screams, he knows that blood is flowing.