As a child Sherlock was just as nightmarish as you would expect. Far from being in control of his emotions, his was a personality of extremes. The things he liked delighted him to a state of joy that had him giggling and jumping up and down and charming everyone in the room. On the other side his tantrums were enough to make the neighbours call to confirm the boy wasn't being murdered.

Boredom made him mischievous. Any lack of attention made him intolerably obnoxious. Sherlock needed constant attention, and unfortunately negative attention—scolding from adults and insults from peers—would do just as well as positive.

Sherlock was arrogant and bossy from the time he learned to talk, cleverer than any of his tutors, and a constant torment to their parents. He was a genius—officially declared so by the Stanford-Binet test (although Sherlock's score, Mycroft discovered with no small amount of smugness when he pinched the envelope from his father's study, was two points lower than his had been when he'd taken it at the same age)—but he was a hazard as well. He was a profoundly destructive child, gleefully breaking apart toys to see what was inside, cutting his skin to find out what was underneath, and lighting fires to watch how things burned.

But in spite of everything Mycroft couldn't help feeling a soft spot for his little brother, who looked up at him with wide, earnest eyes and said 'Mycot' before he'd mastered the more difficult 'r' and 'f' sounds.

For Mycroft, however, a 'soft spot' meant little in the way of displays of affection. Instead it meant an interest in teaching his younger brother as opposed to ignoring him (which he would otherwise have been inclined to do). Mycroft was seven years old when Sherlock was born, and he decided he would teach him about the difficulties in the world so he would be strong enough to face them.

When Sherlock climbed Mycroft didn't prevent him from falling. When he reached for something dangerous Mycroft let him have it. When he hurt himself Mycroft let him cry. These were valuable lessons. When they played games he never let Sherlock win. The little boy threw fits about it, but Mycroft could tell his brother held him in higher respect than their parents.

Their parents, who frankly were too old for a challenge like Sherlock, burned through the local agency's list of nannies in record time, nearly despairing of finding any help at all when finally one arrived who was surprisingly resistant to Sherlock's antics, and who Sherlock seemed to tolerate in return. Their parents had given up on disciplining him themselves, preferring to comply with his every whim rather than endure a tantrum when he was younger or try to win an argument with him when he was older. Mycroft was the only one who could win an argument with Sherlock, and Sherlock resented him doubly for it.

Even as a very young child Sherlock had always been fiercely independent. He hated that Mycroft was seven years older and that many times more capable. Sherlock would have been the smartest boy in England if Mycroft hadn't been there first, holding the title above his head. And Mycroft never lost an opportunity to remind his little brother that he was stupid by comparison. Whenever he felt Sherlock's ego needed an adjustment he would ask him a question he knew he wouldn't be able to answer.

Mycroft would shake his head. "You're a very stupid little boy. How disappointing for Mummy and Daddy."

Such exchanges were necessary; they kept Sherlock's arrogance in check (if only slightly). But Sherlock probably never forgave him for it—one of the many reasons for the bitter rift between them.

The two boys had been irreconcilably different from the start. Even their appearances reflected their opposing personalities. Mycroft had perfectly straight, auburn hair and stoic grey eyes. He rarely cried as a baby, and as a young child concealing his feelings was more natural than expressing them. He learned rules quickly and used them to his advantage, manipulating situations and people insidiously, surreptitiously. His handsome, straight-laced appearance and his mastery of social etiquette made him very charming and very likely to get what he wanted. On the other hand Sherlock's wild black curls and bright, multicoloured irises suggested a kind of chaos that his personality never failed to live up to.

They had both inherited the same exquisite bone structure, ivory skin, and height (though—as Mycroft was thrilled to point out—when Sherlock stopped growing he was the same number of centimetres shorter as the score of his intelligence test was lower: two. They'd had a full on brawl in the garden one Christmas over that point).

They were both sociopathic geniuses but Mycroft had been born with the gift of patience and Sherlock had not. With patience Mycroft had the ability to be diplomatic. He took the time to read people and influence them according to a desired outcome. He refrained from correcting his teachers in order to receive top marks and glowing evaluations. He pretended to like his classmates in order to make connections, always keeping himself in a place of power.

This was the reason why Sherlock had to go in for the psych test and Mycroft hadn't. Mycroft had the wherewithal to pretend to empathise, to pretend to care about other people. Sherlock didn't have the patience. His psych test came back labelling him a 'high-functioning sociopath' and their mother had cried. Sherlock didn't understand. He was only six years old at the time.

"You have to pretend," Mycroft tried to explain.

"But that's boring," Sherlock objected.

Mycroft watched his little brother solve the Rubik's Cube he was playing with, not as fast as he would have done it, but differently. Mycroft would never admit it to his already over-spoilt little brother, but he had always been impressed by Sherlock's intelligence; he had a unique and creative approach to everything he did.

Despite appearances he truly did care about Sherlock, only six years old and already the only person clever enough for Mycroft to speak to without having to feign interest. He would help him by counterbalancing his parents' spoiling and endlessly forgiving manner by preparing Sherlock for the real world. He invented stories about The East Wind to tell him at night.

The East Wind was a force that ripped through the Earth, destroying everything in its path and flinging people into oblivion.

"Only the strongest can withstand it," he explained to Sherlock.

When Sherlock cried, asking why he never survived in the stories (Mycroft took particular pleasure in thinking up new and imaginative ways for little Sherlock to die each night), he replied simply, "The East Wind takes us all in the end."

"It's not fair!" Sherlock sniffed, already improving his ability to stop his tears, learning not to cry.

"No," Mycroft said significantly, "it's not."

The point of the stories was to remind Sherlock he wasn't special, despite their parents insisting he was. Sherlock was a genius, he was beautiful, but he wasn't special. He wouldn't be immune to the forces that would line up against him: the fate of all people who are different. ("When a great genius appears in the world the dunces are all in confederacy against him," Johnathan Swift had famously written and Mycroft remembered it well.) People would hate Sherlock, Mycroft knew. Jealousy combined with the inability to understand him would make it the most vicious kind of hatred, and Sherlock's unwillingness to disguise his arrogance would only make it that much easier for the people who would condemn him. It was obvious—entirely predictable for anyone who knew anything about the world and Mycroft certainly knew enough.

He couldn't change his brother, but he could prepare him. He wouldn't send the boy out into the battlefield snivelling and defenceless. He would give him the necessary armour to fight. The wind might rage around him, but Sherlock would remain standing. Mycroft would see to it.

As a very young child their parents had, for the most part, kept Sherlock close to home. He had private tutors and little interaction with children his own age or even other adults. Because Sherlock managed to offend nearly everyone who was unfortunate enough to cross his path, their parents wanted to reduce his contact with people as much as possible. He called his tutors idiots and his peers dumb and ugly. It did nothing to reduce Sherlock's ego that he actually was better looking, smarter dressed (even as a small child), and cleverer than all of them. It might have done wonders for Sherlock's ability to adjust if only he'd had glasses or plain brown eyes or perhaps even thinner hair.

Fine, Mycroft resolved one evening after some friends of the family walked out angrily following their crying child. If Sherlock wasn't going to play the game—the society game where people interacted in pre-set ways according to strict rules—then he would have to protect him from it.

Anticipating trouble on Sherlock's first day of school Mycroft waited by the schoolyard until his brother inevitably got himself into a fight with about five other boys. Sherlock was irritating, yes, but these imbecilic, inferior children were not worthy of touching him, let alone hitting his (admittedly annoying) face. He didn't care if it was Sherlock's fault (he was almost certain it would be). If Sherlock was going to start fights, then the world had better understand that Mycroft was going to finish them.

Mycroft strode through the swarm of little kids, scooping up a struggling Sherlock and placing him safely on top of a slide. Mycroft turned to the boys glaring up at him, they were older than Sherlock, he guessed about nine years old. But he was thirteen and much taller.

"You don't touch him," Mycroft warned them.

"Or what?" one of the courser boys challenged him. "What are you going to do about it, toff? I'll fight you!"

The boy lunged and Mycroft side-stepped him easily, grabbing the back of his collar and stripping his school jacket off.

"Oi!" he yelled. "Give it back!"

There was a fountain just a few paces away and Mycroft wasted no time in submersing the jacket in the water. Turning his back to the kids who were watching him, he furtively pulled a bottle from his pocket and poured it over the jacket as well. He handed it back to the child.

"You think I care?" He threw on the soaking wet jacket to prove his point. "Is that it? If I punch this little twat in the face,"—he pointed up at Sherlock—"you'll get my jacket wet?"

"No," Mycroft said casually, "if you, or any of you, so much as touch Sherlock again"—he flipped a lighter out of his pocket and bent to their eyelevel—"I'll light you on fire."

With a flick of his wrist he held the lighter under the kid's sleeve. Flames ripped across the boy's jacket. The children standing near him shouted and jumped back. The boy screamed, running in circles and flapping his arms.

He didn't notice when the alcohol Mycroft had poured over the jacket burned off. By his continued high-pitched shrieks it seemed he also had yet to notice that both himself and his jacket were completely unharmed. An old chemistry trick: the water had protected the material and the alcohol had burned off fast; the jacket hadn't even been singed. The boy threw himself on the ground and the few bystanders who hadn't run away gaped in horror. Behind him Sherlock was delighted, clapping his hands and jumping up and down at the top of the slide. His gleeful expression would have been enough to send him in for the psych test if he hadn't already been. He looked at Mycroft like he was a hero.

The teacher who had been supervising a game on the field came running toward them when the kids screamed. Mycroft just had time to give Sherlock a wink before he took off, jumping the fence and returning to his own school.

Needless to say Sherlock continued to be an obnoxious brat throughout the six years he attended that school. Their parents were mystified how it was that he never once came home with a scratch on him.

When Mycroft was fifteen there was a girl.

She was fifteen and she was pretty and her laugh made him smile when almost nothing else did. She was clever and she teased him and she held his hand and one day outside of a café she kissed him before darting off to catch her bus. He eventually concluded that he loved her on the grounds that he had never liked anyone. They had almost a year together before she died.

It was senseless. Random. Meningitis. Dangerous swelling of the brain. The severity of the case was rare in England. A freak occurrence. She was only fifteen.

Mycroft went to the hospital. She was unconscious. The doctors said she wasn't responding well to treatment.

Standing by her hospital bed he told her he loved her, desperation making him want to believe the fairy tales were true—that love could save people or heal them or accomplish anything at all. He was only fifteen.

Like atheists who, when confronted with death, find themselves asking god for help. Fear can make a believer out of anyone. She died within the week, and he understood: Fear can make even the most intelligent people stupid.

Lesson learned. Mycroft would never be afraid again.

The pain, when she was gone, was surprising. He hadn't had much experience with psychological pain, and was amazed at how he'd underestimated it. He felt torn inside out, like his nerves were exposed and everything hurt. He was drowning and he couldn't breathe and he knew that this must be worse than dying, because dying has an end.

A fate worse than death and it was entirely preventable, he realised in time when the wound wasn't so raw and cold logic could soothe the burning pain. It was really quite simple. If one never fell in love, one would never experience such suffering. Because people were not permanent. People could be ripped away at a moment's notice. Cancer, a missed red light, a spontaneously rupturing blood vessel, a random act of violence. The East Wind takes us all in the end. It was incredible people were stupid enough not to understand the obvious truth: All lives end. All hearts are broken. Caring is not an advantage.

He realised all of this before his seventeenth birthday and he was determined to teach it to Sherlock. He'd been through hell and back but Sherlock didn't have to. He could avoid all of it, all of the pain. Mycroft had always been level-headed and stoic to the point of unnerving his teachers. Thinking about what loss had done to him he knew he couldn't allow it to happen to Sherlock. Because if it hurt him that much, he was certain it would destroy his more sensitive little brother.

When Redbeard died it was the ideal opportunity for a lesson.

They had to put him down, that much was clear. Redbeard was old, ten years old. The veterinarian said the lifespan for dogs like Redbeard was between ten and twelve years. Expensive surgeries were halfheartedly discussed for Sherlock's sake. But the vet shook his head, explaining invasive surgeries would be difficult for an old dog. They would only prolong the inevitable, and not for very long. Sherlock was nine years old. He would be devastated.

Redbeard had originally been a birthday gift for Mycroft the year before Sherlock was born. His name was Charlie then. But Mycroft, six years old at the time, hadn't been interested. The puppy was messy and chaotic and dumb and he didn't really understand how to play with it, or why doing so would be desirable. The puppy, probably sensing his disinterest, had never taken to him either. But Charlie fell in love with Sherlock right away, sniffing and licking the baby, and wagging his tail when Sherlock laughed. Mycroft remembered the dog used to sit by, watching like a concerned nanny while Sherlock crawled around the living room. In Mycroft's memory he had always been Sherlock's dog.

When Sherlock was five he became obsessed with pirates, only wanting to watch pirate movies and only wanting to hear pirate stories at night. He played 'pirates' in the garden with Charlie, who was nicknamed Redbeard for the game, and Sherlock was Captain Shezza. He wore a bandana over his head and tied one around Redbeard's neck. He had a plastic sword and the two of them went on many daring adventures, some of which involved attacking Captain Mycroft on his way home from school.

Captain Mycroft, however—twelve years old at the time and Shezza's most formidable enemy—was prepared for this, sometimes engaging in a bit of swordplay (stealing the plastic sword from Redbeard's collar) if he was feeling indulgent. He was already part of the fencing club at his school and he corrected Sherlock's posture, teaching him about lunges and parries.

If he was not feeling indulgent, which was more often the case, he simply dodged Sherlock on the front path, lifting him up over his shoulder and carrying him through the house—Sherlock struggling and shouting commands to attack his captor at Redbeard, who insubordinately trotted alongside Mycroft—and putting him down again in the back garden. (Sherlock had always been such a skinny child; it was almost laughably easy to carry him even when he fought. He gave their mother a constant headache by refusing to eat. Even sweets could rarely hold his interest.) Mycroft would lock the sliding glass door behind him for an hour of peace in which he could study, and Captain Shezza and his faithful First Mate Redbeard could go after less challenging foes.

The name stuck and Charlie became Redbeard fulltime, even after Sherlock's pirate phase faded out. For Sherlock, who had failed to socialise properly before school, and who regularly made the children at school cry, it would not be an exaggeration to say Redbeard was his only friend. It didn't matter how much verbal abuse he shouted at the dog when he was upset, Redbeard was always there to greet him eagerly at the door. And Sherlock loved him for it.

But Redbeard was one year older than Sherlock in human years, and by the time the dog was nine he was fifty-five years older than Sherlock in dog years. Sherlock was eight when Redbeard began to slow down. He had arthritis in his hips and he couldn't run the way he used to.

Mycroft remembered watching Sherlock through the sliding glass doors as he played in the garden one day. Sherlock was running and looking behind him he noticed Redbeard struggling to keep up. Sherlock stopped abruptly. The look on his face suggested he almost, but probably not entirely, grasped the importance of the moment. So begins the lesson on impermanence, Mycroft had thought. It was the hardest lesson to learn.

A year later it was clear they had to put him down. He was old. He was in pain. The line had been crossed—it would be unkinder now to let him continue to live. Except for school, which their parents forced him to attend, Sherlock never left Redbeard's side in that final week.

The night before they had arranged to have Redbeard put down Sherlock was sitting on the floor next to him. He looked up at Mycroft with tearstained eyes.

"Mycroft, please," Sherlock said, tears rolling down his cheeks. There was no continuation of the sentence, no complete request. There couldn't be. There was nothing Sherlock could ask of him that would make any logical sense. But Sherlock was nine years old; he was on the floor next to Redbeard, looking up at him and asking him anyway.

It was the first time his little brother asked him for something he couldn't do.

Sherlock fell asleep on the carpet beside Redbeard and at three o'clock in the morning Mycroft knelt by his side. He put his arms around his brother's shoulders to raise him up, and still half-asleep Sherlock automatically, like he'd done when he was much younger, wrapped his arms around Mycroft's neck. Mycroft lifted him without difficulty—the boy was too thin—and carried him to Sherlock's bedroom. When he put him down in his bed he was already sleeping—that deep, trusting sleep only children can manage. When he woke the next morning Redbeard was gone.

Sherlock was inconsolable the next day, though their parents tried. His brother's fury and his anguish only confirmed what Mycroft already knew—Sherlock would never be able to handle the pain if it were a person who died, a person who he loved and who perhaps loved him back. It would wreck him beyond repair. He needed to learn now, before it was too late.

A few days later Sherlock was looking out at the back garden and Mycroft caught tears in his eyes in the reflection of the glass door. He stepped up behind him.

"You're stupid, you know."

Sherlock whirled around brushing his eyes furiously. "I am not!"

"You are," Mycroft insisted. "You made a mistake and now you're crying about it like a baby."

"I'm not crying!" Sherlock yelled, tears welling in his eyes. He turned his head aside. "What mistake?"

"You loved him," Mycroft said simply. "This is what happens when you love someone."

"All living things die," Sherlock sneered, "whether you love them or not, everybody knows that."

"But it doesn't have to hurt, does it?"

"What does that mean?"

Mycroft sighed. "It's disappointing how slow you are, little brother. Come now, try to think. Do you like the way you feel?"

"It's horrible"—Sherlock glared out into the garden—"I hate it. I want it to go away."

"It's weakness," Mycroft explained. "This is why you would never survive The East Wind. You're weak."

Sherlock didn't respond.

"Think, Sherlock. I didn't want Redbeard to die. So why am I not crying?"

"You don't cry," Sherlock muttered.

"I am human, Sherlock; I am capable of tears. No, try again."

Sherlock shrugged. "You didn't love him."

"Precisely."

Sherlock looked up at him.

"To love is to be vulnerable. No one can hurt you if you don't love."

"You don't love anyone?"

"No," Mycroft said, feeling the cold, hollow place inside of him the girl had left when she died.

"What about Mummy and Daddy?"

"Love is only weakness."

"But, what about…" Sherlock hesitated.

Mycroft thought about his answer. He loved Sherlock. Of course he did. Sherlock was horribly annoying and stupid at times, but he was also his genius little brother who Mycroft knew even then he would spend his life protecting. Because Sherlock was always going to be in danger. The boy was reckless, antagonistic, ostracized by adults and his peers alike: a magnet for trouble and even violence. When the girl died Mycroft had vowed to never be foolish enough to love again, but it was already too late when it came to his brother. Mycroft could remember the exact moment he knew he loved him.

Initially he hadn't been keen on Sherlock at all. Having a baby in the house was most inconvenient, not to mention noisy, and he didn't understand in the slightest why his parents felt it necessary to keep him. He was seven years old, but he had already heard of adoption agencies. However, one afternoon, around six months after they brought him home, Mycroft was sitting on the floor of the living room, back against the sofa, watching telly. Sherlock had recently learned to crawl, and he was doing so around the living room. After a while he crawled over to Mycroft and looked up at him uncertainly. Even then his hair was already curling thick and dark, and his eyes were as bright as ever.

"What?" the seven-year-old Mycroft asked defensively. "What do you want?"

In response Sherlock climbed up onto his lap and flipped over onto his back. Startled, Mycroft instinctively put his arms around the baby to support him. Sherlock was asleep in a minute and Mycroft felt a pull from behind his chest. From that moment on it was too late. He loved his little brother, and it would be his responsibility to teach and protect him, come what may.

And now he was obligated to set a good example. He would lie to Sherlock to teach him the correct behaviour. His weakness didn't have to be his brother's.

So, at the age of sixteen, Mycroft looked down with clear eyes at his nine-year-old brother and said, "No, Sherlock, I don't love you."

Sherlock flinched, fresh tears springing to his eyes. "Good," he said, not meeting Mycroft's eyes but glaring at his chest. "Because I don't love you either! I hate you!" He ran to his bedroom, slamming the door behind him.

It was an unpleasant but necessary lesson. And a few months later, Mycroft was rewarded with evidence that his clever brother had internalised it. Their parents asked Sherlock whether he'd like a new puppy and Sherlock shook his head with some vehemence declaring that pets were useless and stupid.

And as far as he could deduce (which was regularly even further than Sherlock), his brother never loved anything or anyone again.

Until John Watson, that is.

It was after two o'clock in the morning when Mycroft stepped quietly into John Watson's hospital room. His brother was sitting in a chair, half-lying on the bed, one hand clutching John's wrist.

Sherlock didn't stir when he entered and Mycroft knew that was the morphine, providing him with a numb, dreamless sleep.

Mycroft had been certain for so many years that Sherlock would avoid this. His reaction to Irene Adler's death should have been the worst of it—a mere bump in the road: something unpleasant but far from unmanageable. That was how death should be: A minor disruption; sincere condolences; nothing more.

But evidently it had taken just one military doctor to turn everything upside down for Sherlock. Mycroft had seen it right away. That Sherlock had chosen man was an interesting turn of events, although not unexpected. As little patience as Sherlock had with people in general he'd always seemed to have less with women.

But initially he was surprised that it was John Watson whom his brother deemed worthy of his affection when for twenty-seven years no one else had been. But after just a moment's consideration he realised it wasn't all that surprising. A soldier encompasses an interesting combination of obedience and willpower—an ideal personality for his brother, who would require a certain amount of submission to accept his domineering personality, but also a significant amount of backbone to win his respect. Factor in John's addiction to danger, his bravery (or the right kind of stupidity), the speed at which he'd become fiercely protective of Sherlock (Mycroft had tested him), his cynical sense of humour, his patience and his loyalty, and he was in many ways the perfect companion for Sherlock. Even his shorter height and lower intelligence were necessary, due to Sherlock's disdain for anyone taller than himself and his proven tendency to clash, sometimes violently, with people of equal or higher intelligence.

Add the last remaining variable—that John had fallen for Sherlock almost immediately, despite his brother's frankly shocking list of flaws—and Sherlock had caved, falling for John in return. Mycroft had seen it the night John shot the cabbie.

Afterward he watched Sherlock trying to pretend it wasn't true. And John being oblivious—relying too heavily on his previous heterosexual history to see things as they really were. There was a point when Mycroft thought perhaps the two of them had found such an unlikely balance that they could remain in limbo forever. But then Sherlock had decided not to tell John he was alive after he died and John got married and Mycroft was forced to remind Sherlock that he had, indeed, told him not to get involved.

Sherlock had called him from the wedding. Why? Of course John and Mary didn't care whether he attended. No, Sherlock only called when he needed something. And maybe that day at that wedding his little brother had needed him. The two of them could have stood in the doorway disparaging the wedding guests who had the audacity to enjoy themselves at such a staged, specious and affected ordeal. But for Sherlock the mockery would be just as contrived and hollow as the reception. This time his primary reason for hating the wedding would not have been based on principle. It would have had everything to do with losing John. And Mycroft had no interest in humouring his brother by standing with him on the periphery of the party and allowing him to play pretend.

Don't fall in love, Sherlock. You know what happens.

"They get married, Sherlock," he'd finally said when Sherlock made him spell it out on the phone. "I warned you: Don't get involved."

Of course by that time it was far too late. But Sherlock denied it: "Involved? I'm not involved."

It was all very childish. The best Mycroft could do then was to remind Sherlock of the lesson he'd learned a long time ago.

"Oh, by the way, Sherlock, do you remember Redbeard?"

Sherlock had chafed at the insinuation. "I'm not a child anymore, Mycroft."

Standing in the darkened hospital room Mycroft looked grimly at the unconscious and wrecked form of his brother holding desperately onto John's wrist as though it were a life preserver. The tableau gave him a sense of déjà vu. He'd seen this scene before. He'd seen it the night John shot the cab driver. He'd watched Sherlock realising, understanding—watched his eyes as John was suddenly reinterpreted in his mind. And the look on his brother's face then, eye's never leaving John's—Mycroft knew what it meant. It meant this scene, here, now, in the hospital. Like a premonition, Mycroft had seen Sherlock just as he was now at John's bedside. But of course there were no such things as premonitions. It was simply the balance of probability. His brother's work was dangerous; it was only a matter of time before John ended up here, either dead or barely alive. It was incredible it hadn't happened sooner.

Mycroft tightened his grip on his umbrella. There may be a certain kind of sadness for the child who loses his dog, but there's a certain kind of danger reserved for the person who loses love.

No, Sherlock was not a child anymore. And of all the lessons learned, this was the one Mycroft had hoped he would never have to.