Mostly brother relationship between Sherlock and Mycroft, with hints of Sherlock/John.
Both Sherlock and his older brother were intelligent, anybody could tell this after spending a couple of seconds with either of them.
At the age of three Mycroft had argued his way out of nap time, and by the time he was seven he was reading Dickens to his two-year-old baby brother.
Perhaps their parents had hoped for a more ordinary child by having a second after Mycroft, but that hope was in vain.
For Sherlock's fourth birthday he was asking for his first encyclopedia of science, and when his sixth year of life was coming into sight he proved that his teacher was having an affair with the headmaster.
Mycroft and Sherlock were not normal boys.
However, there were several noticeable differences between them.
Sherlock had never gotten to grips with socialising. He didn't have friends, and he didn't want friends. He was fast to prove that he was smarter than anybody in his class, including the teacher, and often displayed a smug way of going about it.
When Sherlock was upset or angry, he shouted and screamed, throwing things around the room, before sulking in a corner for hours, or sometimes even days.
Their parents had always known that Mycroft was clever, but Sherlock seemed to be a genius, or possibly even something beyond that.
The way that Sherlock could tell simply by looking at them, everything that happened to them that day. So they naturally began to favour their older son, who seemed a lot more promising in the eyes of parenthood than he had before his brother was born.
The truth of the matter was, that Mycroft was just as clever as Sherlock, possibly even more so. Apart from his small lapses that showed his intelligence as a young boy, as he got older he seemed to settle into the category of 'just intelligent'.
He scored high in the tests at school, but only just above the second, even letting himself drop below to third place when the teachers started discussing his and his brother's name in the same sentence.
Mycroft had a great number of followers, they weren't friends exactly, but Mycroft was popular; and that was a great stride above his brother.
Whenever grandmother came round, Sherlock would tell her his predictions on how much longer she'd live, while Mycroft pecked her on both cheeks and told her how well she was looking.
Sherlock would scowl at him every time he said something like this, and Mycroft would just ignore him.
Despite the appearance he led everybody to believe, Mycroft just thought differently to his brother. He didn't care for people and their short wasted lives; their endless chatter about what to do at the weekend and who was dating who in the papers.
In many ways this made Mycroft crueller and colder than his younger brother.
He saw people like stepping stones across a river. While his brother was trying to work out how to get across said river by an alternative route, Mycroft was hopping across the stepping stones to the other side.
People were so easy to please. They liked to see you smile, they wanted you to flatter them, they loved to hear how great they were. Mycroft could read people like a book, including the one thing that his little brother could never see in people, emotions.
Sherlock saw a man tugging at his jacket and deduced that he was agitated about something.
Mycroft would hear the tone of his voice and see the look in his eyes, and see beyond his agitation. He would see a man sometimes waiting for a late train because he wanted to visit his mother, or a man who'd just discovered a wife who'd been having an affair with his best friend.
The hurt, the sorrow, the disappointment; Mycroft lapped it all up.
He'd reach the same end as Sherlock, but he'd have taken the faster route, with far less leg-work.
There was only once when Mycroft let this façade slip in his childhood life. He'd kept his genius hidden, maintained a successful line of acquaintances that had led him where he wanted to go, until he was accepted into that boarding school.
And perhaps it was the year where Sherlock showed the want for a connection that previously he had shown no interest in.
The school itself was of high standing, with a tough entrance exam that only the best ever passed. Despite his intelligence, Mycroft's parents didn't have too much hope for him passing the exam.
Mycroft passed, but only just. He was the student in the year with the lowest score, but it had been enough for him to get in.
On his last day at home Sherlock had come to find him.
The small six-year-old boy pushed his way into Mycroft's room, his encyclopedia under his arm, and his eyes narrowed determinedly.
Mycroft's first thought was what-on-earth his brother was doing. Generally the two brothers ignored each other; Sherlock even seemed to forget once in conversation, that he even had a brother.
This hesitation, he realised very quickly, had cost him any chance of disproving Sherlock's sudden accusation.
"Why don't you act clever?" The young boy demanded, his voice so fierce and decided, that any other person would have flinched.
But Mycroft remained calm, his mind beginning to calmly work out an argument against this.
"I am clever Sherlock..." No point in denying it "...But I'm not as clever as you, that's just the way the world works."
It was wishful thinking, hoping that his brother would fall for this. Sherlock didn't bend to flattery like most boys his age (and older) did.
Mycroft began to search Sherlock's eyes for some trace of emotion that he could use against him. He was still looking when Sherlock spoke again.
"Don't lie, how else could you pass an exam twice as hard as any you've ever sat and still pass?" Mycroft watched Sherlock's own eyes look him up and down. Mycroft knew his appearance wouldn't give anything away, he just had to be careful what he said.
"I did get the lowest score Sherlock" he reminded him, "I must have just gotten lucky."
"No," Sherlock said it blankly, but in that moment, Mycroft saw something flash in his eyes, pride. He had him, play Sherlock to his pride and he could win this argument.
"What do you mean, 'no'?" Mycroft asked innocently, feigning surprise, pretending to be uninterested in what Sherlock had deduced.
"Your pencil," Sherlock pulled something from his pocket and handed it to Mycroft.
Mycroft found himself holding the red HB pencil he had used in the maths paper of the entrance exam. It took him just moments to realised his mistake, but only his eyes betrayed him, and he knew that Sherlock wouldn't be looking for answers there.
"You haven't used the rubber once. For somebody who only just passed the exam you seemed pretty confident in your answers," Sherlock had the beginnings of a confident smug smirk creeping onto his lips.
Mycroft sighed, then did what he did best. Lie like crazy.
"I had another rubber with me" he shrugged, "and believe me, I used that one right down to the bone,"
"One of those big rubbers was it?" Sherlock questioned,
Mycroft nodded, "not too big though, like the ones they sell in Woolworths in town."
Sherlock's grin grew wider. He began to approach Mycroft with one hand outstretched in a demanding way. "Show me your hands Mycroft."
Slowly, Mycroft showed his hands to his younger brother.
Sherlock poked at them with his fingers, examining them from every angle then let out a small sound of scornful laughter.
"If you'd used a rubber that size there would be marks on your hand, especially if you'd used it 'right down to the bone'. Plus, you didn't get just the lowest result, you got one mark above the pass line; statistically on so many exams, the chances of that happening are 10,000/1, you made sure you got that mark deliberately."
Mycroft made an effort to control the worried look in his eyes. Even if Sherlock couldn't read his expression, he knew he would meet people that could. This was good practise for emotional control.
"So..." Mycroft spoke softly, with a slight purr to his voice, "are you saying I'm smarter than you?"
There was a sharp pause.
Could Sherlock overrule his pride to pursue his suspicions about him?
As Mycroft watched him during this pause, he knew he'd at least one half the battle.
"I-I didn't say you were as clever as me" Sherlock stammered, anger rising in his voice, "you're still stupid like the rest of them, all I meant was that your not as stupid as you act!"
"And how would you know?" Mycroft questioned, "when someone is as clever as you, they probably can't tell the difference between the class idiots and the smart kids."
Sherlock hesitated, then stormed out of the room, still holding his encyclopedia under his arm.
Mycroft wondered why he'd brought it.
Then he felt a strange clutch in his chest when he saw that one of the pages had been folded in the corner. Page 105 or 106 he managed to narrow it down to. They were the pages on the solar-system.
By the look of disappointment he saw flash in Sherlock's eyes, he concluded what his brother's intentions had been.
For a moment, Mycroft found a strange emotion creeping through his chest.
It wasn't guilt. It couldn't be guilt. Mycroft Holmes didn't feel guilty.
He sniffed indifferently, tossing a few more socks into his suitcase.
Besides, it was a ridiculous conclusion to make. Someone as clever as Sherlock certainly didn't need something as obvious as the solar-system explained to him. Did he?