One of the earliest memories that John can recall is the feeling of a gun in his hands and Harrys hands over his to guide him correctly.
She had still been Harriet at that time. Her twelve year older hands easily encompassed his three year old hands as they gently showed him the proper way to hold the gun. Later as he grew they went to all the different kinds of guns and even knives.
"This will be our little secret." she had whispered to him. "We can't tell anyone."
John nodded eagerly. Harriet was fifteen years old and the epitome of cool in his eyes. He wanted nothing less than to be like her.
Her training him became their little secret. At night or times when they had the house to themselves they used the time for her to continue her teachings.
Later, as he continued to grow, they learned together the anatomy of the human body through endless amount of books. Together they learned the fastest ways to kill a human being in the proper places.
John was three years old when Harriet, still Harriet back then, started to teach him.
He was four when he learned about every gun there was and what each one was specifically made for.
He was six when she gave him his first gun. He had always used hers but this one was his. His officially.
He was seven when she gave him a box of knives that were just perfect for throwing.
He was nine when they learned the human body together.
He was ten when he finally realized that older sisters didn't teach their younger brothers these things.
He was ten and a half when his mother finally got the answer from him after finding him cleaning his knives.
Harriet, still Harriet, hadn't gotten angry with him. Simply upset. She knew that they wouldn't be able to keep it a secret for much longer. She also no longer lived at home and instead lived on her own but their parents knowing meant she might not be able to teach John anymore.
"It's because they're stupid." she explained to him over the phone that night after his mother had forbidden him to contact her anymore. "They're stupid and they don't realize that you need to know this Johnny."
"Mom said that it's bad and dangerous." John said quietly so their parents wouldn't hear.
He could hear the smile in her voice. "They say a lot of things are bad, that doesn't mean that they're right."
That night when John was in bed he pondered over who he thought was right and wrong.
Mom and dad both said that knowing how to kill people drove people insane. That it would make them bad and they would end up going to hell.
But they said the same thing to Harriet when she came out and said that she was a lesbian. There was nothing wrong with Harriet being a lesbian, John decided, and there was nothing wrong with knowing how to kill properly.
Besides, he mused as he turned to his side and thought of his sister, it wasn't like he was going to actually kill people.
"I want to live with you." John said to Harriet over the phone the next day.
Harriet was quiet for a moment before she said "I'll take care of everything Johnny. Don't worry."
A week later their parents were dead. A car accident the police man said. Harriet was standing next to him holding his hand tightly. The both of them were crying. When John lifted his arms towards her she obediently hugged him tightly.
He didn't know if the smile on her face was real or something he imagined.
He also never asked if she had done it so that their parents had died because of her.
As John continued to grow Harry, she became Harry a short time ago and when he asked she had simply shrugged and said she liked it better, continued her lessons.
"I have an employer." she explained to him one night. "He tells me what I need to do, because my skills are better than others and he only gets the best, and he's been having his eye on you Johnny."
"What do you do?" John asked.
"I kill people." Harry said simply. "He pays well and I have fun doing it." She laughed. "You show so much promise, little brother. Once you turn eighteen he'll be coming to you to assign a contract with you." She wagged a finger towards him mockingly threatening. "But you need to know, once you're in you never leave."
John wasn't sure if he wanted to have anything to do with Harry's second life. She had two of course. The first was the one that involved him, her newest girlfriend Clara, and a small group of people she meets at the pub.
The second was the one he barely knew. That one was where her skills, skills that John knew that she herself taught him since as long as he could remember, were put to use.
"What do you want me to do?" he asked instead.
Harry hesitated for a moment. She took a swing of the drink in her hand and glanced around the room. Her employer, John didn't know his name, paid very well to the ones he was pleased with. She lived in a life of luxury where she didn't want for anything. The room they were in declared it in their expensive cloths and items that decorated the walls, the tables, and every other surface if only to show off that she can afford it.
If John joined her he would never be short of money or anything that he might want.
At the cost of lives, some innocent and some not so much.
"I want you to be happy." she finally said. She looked at him. "You're my little brother and I love you. I taught you this because I knew you needed to know it, in this world of dogs you need to be bigger, stronger, and deadlier."
She smiled at him. "I just want you to be happy."
That was the last time John saw her before his eighteenth birthday where he left home to dorm at a medical school. Despite his protests Harry paid for all his courses and hacked information to know which books he needed to have them delivered the same day. His complaints fell on deaf ears and any attempt to reimburse her or return the books were met with dead ends.
"If someone representing a man named 'JM' don't go with them." she warned him. "Tell him Moran says no and thank you."
The warning simply confused him. JM and Moran.
However on the day of his eighteenth birthday he was returning from his class and going towards his dorm to shower and change for dinner with Harry that a man in a suit approached him and said "My employer would enjoy having dinner with you and discuss a possible employment."
John stared at him for a moment before he asked "JM?"
The man nodded.
"No thank you." John said. "Moran said no."
The man contemplated John for a silent and long moment before he nodded curtly and left in a car that John hadn't noticed until then.
When he mentioned it to Harry over dinner that night she had smirked and said "Don't worry, they won't bother you again."
The next years of medical school passed quickly however filled with studies that the only time John managed to find time to talk to Harry was during their birthdays and the time their class was going over the anatomy of the human body.
They had a bit of a laugh over that.
They only had one real fight. When he told her that he had enlisted to become an army doctor.
She had screamed at him in fear. "You'll die!" she screeched. "You'll die!"
John assured her that he wouldn't die. That he would write whenever he could. That everything would be okay.
It was the first time they fought.
It was also the first time that he had ever seen her cry.
So he was trained as an army doctor.
Then he was sent to Afghanistan.
Months passed there in a sandy blur with the count of people coming into his tent for medical aid going to uncountable numbers. He wrote to Harry anytime that he was able to as promised and called whenever he got the chance.
Not surprisingly the lessons she had given him had helped him in a great effort. The times he was on the battlefield the instincts that had developed right alongside all his other senses ensured that he killed the people before they killed him.
Then he got shot after racing onto the battlefield in an effort to save the ones that had gotten hurt and weren't in the condition to get back on their own and sent back to London.
Harry was the one who met him at the airport. That was the second time he ever saw her cry.
This time he flat out refused to accept her money and said that "Perhaps it was time for her to stop babying him and let him live independently for a change?"
There was understand in her eyes however she refused to take back the phone that she all but threw at him.
"Too many memories." she had said. A glance at the back revealed it had been a gift from Clara.
Months passed and in that time he had become a flat mate to Sherlock Holmes.
The pool incident happened and they were introduced to Jim Moriarty.
John fervently hoped that there was two JMs that someone who knew how to kill could work for.
His fear only grew when Harry never answered her phone anymore when he called her.
He refused to believe in the signs, (the people being killed in such a familiar way, Harry never meeting his eyes anymore during the rare and becoming rarer times that they met, the guilt in her voice when she talked to him).
He even managed to follow himself until the moment Sherlock and Moriarty finally decided to have their final battle.
And of course both sides brought their best and the one who would throw themselves in front of a bullet to protect the person that was theirs.
Sherlock and Moriarty were unarmed sans their words and knowledge. It was only John and Harry that had guns.
Guns that were aimed at each other.
At that moment John really realized just how little alike they looked. John had favored their mother while Harry had favored their father. To such a degree that neither Sherlock nor Moriarty were able to see the bloodlines.
John tried to clear his mind as the army, as his sister, had taught him. It wasn't his sister in front of him now.
This was the sniper that was whispered in the underground. The one that never missed and never allowed a single emotion to cloud their judgment.
This, was Sebastian Moran.
Neither one of them were listening to the other two in the room. They were aware of Sherlock and Moriarty talking however they didn't hear a single word.
All John could see was his sister.
The sister that taught him practically everything he knew about guns and killing.
The sister that no doubt killed for him.
The sister that would always protect him.
The sister that ensured that they would always be together.
They sister that he loves.
He sees the conviction in her eyes first and before he could make a single move, not even time enough to widen his eyes, her gun shifted and the bang rang out clearly throughout the room.
Moriarty fell to the ground dead, the bullet quite visible in the side of his head.
I do not own Sherlock. This was originally a request on the Sherlock Kink Meme.