"You -"

"It was for your own good."

"Why?"

Mycroft sighed and looked at his brother. "I promised Father -"

"Why?" Sherlock slammed his hand against the table. "You promised Father you'd take care of us? You... you sent John to Afghanistan -"

"I was merely fulfilling his own wishes."

"And keeping my letters did any good to me?"

After Moriarty's visit to 221 B Baker Street Sherlock exploded. He didn't talk to John for weeks and refused to leave his own room. Nothing, not even a good case in the middle of this nightmare would cheer him up or made him forget the man living with him was that lost brother he had always had some vague memories about.

Why on Earth... why he had to fall in love with John Watson who was no one else but his own brother?

They kissed. Sherlock kissed him and John kissed him back.

And they were brothers.

Adoptive brothers.

"I did what I thought was the best for both of you," Mycroft spoke firmly, yet calmly. "I'm the big brother, as Mummy always said, and I ought to -"

"As soon as this finishes -" Sherlock looked away and then back to his brother. "We're adoptive brothers. John doesn't even has our name."

"You can't."

Sherlock glared at him with angry, furious eyes. "I'm not asking for your approval."

"Sherlock, nothing can happen between you and John. John is not... John is not just that boy our parents adopted."

The detective froze.

Maybe it was time to say the truth.

"No."

Sherlock looked at John's jumper left on the sofa. That jumper their mother knitted for him before dying. And Sherlock could still remember that day so well, the day their mother gave John that jumper and said it would always keep him warm.

Their mother knew.

Mycroft knew.

He himself knew but never said anything. Maybe he just refused to believe it.

John was not only the boy their parents adopted.

John was their Father's biological son.

"John is Father's bastard." Mycroft whispered, as if he were afraid John would hear even though he was not there. "He's the product of an affair he had. He didn't give John his name when he was born because that is the way John's mother wanted it to be. She made her then husband believe it was his. He..." the politician trailed off and his eyes met Sherlock's. "He didn't want to hurt Mummy. Years later he was eventually told about John's mother and her husband's deaths. As you know John lived with his sister Harriet but her drinking problems almost killed John in a car accident. That's when -"

"When Father told Mummy about John."

"Yes."

"So they adopted him."

"Father -"

"They lied when they said it was only for the sake of the political campaign," Sherlock cut Mycroft off. "It was Father's atonement. And Mummy obliged."

Mycroft rubbed his forehead tiredly. "Mummy lost a baby -"

"I already know that story. What I want to know is why they never told us. Why they never told John."

"Do you really believe something would have changed if we had been told about John's origins from the beginning? You were a child, Sherlock."

Sherlock stood up and opened the door for Mycroft, a clue he indeed wanted to be left alone. "You're not telling John a word about this."

"He has rights."

"John will never know about this," Sherlock said darkly. "Or you'll regret it."

Mycroft, by just looking at his brother, knew how hurt he was. "Sherlock... I did my best to protect both of you. Forgive me if I failed and my protection wasn't enough."

"Leave."

"Tradition, John. Our traditions define us."

John smiled sarcastically. "So total silence is traditional, is it? You can't even say, 'Pass the sugar.'"

"Three-quarters of the diplomatic service and half the government front bench all sharing one tea trolley. It's for the best, believe me," the politician poured himself some whiskey and turned to face John. "They don't want a repeat of nineteen seventy-two. But we can talk in here."

The doctor glanced at a copy of The Sun and frowned. "You read this stuff?"

"Caught my eye." Mycroft tried to find any signs on John, signs which could reveal if anything happened since his visit to Sherlock. "Saturday: they're doing a big exposé."

"I'd love to know where she got her information."

"Someone called Brook. Recognise the name?"

John frowned. "School friend, maybe? Can't remember, really. Sherlock didn't have many friends."

"Of Sherlock's? But that's not why I asked you here."

"Who's that?" John asked once Mycroft had opened a file and showed him some papers.

"Don't know him?"

"No."

"Never seen his face before? He's taken a flat in Baker Street, two doors down from you."

"Hmm! I was thinking of doing a drinks thing for the neighbours."

"Not sure you'll want to," Mycroft handed him more folders. "Sulejmani. Albanian hit squad. Expertly-trained killer living less than twenty feet from your front door."

"It's a great location. Jubilee line's handy."

"John -"

"What's it got to do with me?"

Irritation.

John was showing signs of irritation, the politician deduced, something had indeed happened in Baker Street.

"Dyachenko, Ludmila."

"Um, actually, I think I have seen her."

"Russian killer. She's taken the flat opposite."

"Okay... " John raised both eyebrows. "I'm sensing a pattern here."

"In fact, four top international assassins relocate to within spitting distance of two hundred and twenty-one B. Anything you care to share with me?"

John said anything first. "I'm moving?"

"It's not hard to guess the common denominator, is it?"

"You think this is Moriarty?"

"He promised Sherlock he'd come back."

"If this was Moriarty, we'd be dead already."

Mycroft managed a tiny smile. "If not Moriarty, then who?"

"Why don't you talk to Sherlock if you're so concerned about him?"

Ah. There it was. Mycroft couldn't help but look away. Suddenly he realised, after meeting his brother and revealing the truth, that he had made a huge mistake. Because maybe, just maybe, John felt the same for Sherlock.

"Oh God, don't tell me."

"Too much history between us, John. Old scores; resentments."

"Nicked all his Smurfs? Broke his Action Man?" John smiled. "Remember he said he would never forgive you?"

The doctor placed the folders back to the table and turned to the door. "We both know what's coming, John." John turned to him. "Moriarty is obsessed. He's sworn to destroy his only rival."

"So you want me to watch out for your brother because he won't accept your help. Right."

"If it's not too much trouble."

As soon as John left and the door was closed Mycroft called Sherlock."Done." He only needed to hear the confirmation to finish the call and wait.