Inspired by Sherlock and Mycroft's smoking scene in His Last Vow. Smoking, teen Mycroft, kid Sherlock, references to corporal punishment but for the purpose of plot development - it's not some weird kinky showdown. Written with my friend Amy in mind. Enjoy x

Mycroft leant back against the cold, grimy surface of the stone wall, trying desperately to clear his mind of the never ending buzz of thoughts as he took his first deep drag of the crumpled cigarette. Of course, when smoking one's first cigarette it is generally advisable to open your eyes, and Mycroft found a moment later – he could barely stifle the huge, shaking cough that rumbled up his chest and tried hard to explode from his mouth. However, with several attempts and a deep breath, the cough remained inside of him, silent to all of those except for his gasping lungs.

"Smoking, Holmes? I'm surprised at you."

The fifteen year old, who usually prided himself for his innate sense of what was around him, jumped when he heard the familiar voice behind him. Stephen Barker, a gangly, annoyingly skinny prefect from the year above who positively delighted in seeking Mycroft out and trying to catch him in any remotely compromising situation.

"No." Mycroft immediately replied, turning around and crushing the still-smoking cigarette against the wall in one fluid movement that seemed totally at odds with his larger frame.

"Don't lie, Holmes – I'm not an idiot." a smug smile appeared on Barker's face, his upper lip curled slightly at the acrid smell the tobacco had left in the air. "I'm sure your housemaster would be very interested in hearing about this."

"I'm sure he'd also love to know that you've been shagging the cook's daughter – behind the bins, I can see. How delightful." Mycroft's tone was perfectly civil, indicating some trace of politeness should be present in the words that were so blatantly threatening. Barker's eyebrows shot up, his dark brown eyes widening and his mouth opening slightly in surprise at Mycroft's words.

"How did you- what do you mean?" Barker exclaimed, staring straight at Mycroft. Mycroft laughed, feeling a little easier now that the vaguely pleasant buzz from the cigarette was beginning to kick into his system and the situation was practically jumping into his hands.

"Well, I don't suppose you personally wear perfume, nor do you writhe around in fruit peels and stain your trousers on a daily basis. It's obvious, really." Mycroft's voice had gained a slow, almost lazy manner as he easily let the words flow from him, an odd sense of satisfaction going through him at the expression on Barker's spotty face.

"You wouldn't dare tell – I'd be expelled!"

"Are you really sure about that, Barker? Do you really want to risk it?"

Barker hesitated for a moment, before narrowing his eyes and glaring at Mycroft.

"I didn't think so." Mycroft gave Barker a mild smile. "I suppose we'd better be off, then – lessons start again in a few minutes, and you've got some...smartening up, to do."

With that, Mycroft swept off, leaving Barker to fantasise about kicking his head in.

Mycroft was in the midst of copying down a ream of information from the blackboard in History when the door to the room opened, which caused him to briefly look up. Stood at the door was Barker himself – however, his usual condescendingly smug face was replaced by a mask of fear.

"Excuse me, Mister Jones – can I have Mycroft Holmes, please? The headmaster wants to see us both."

Mycroft's head snapped up at the mention of his name, but was able to immediately overrule any thought that Barker had ignored his warnings and gone to his housemaster anyway. For one thing, a visit to the headmaster was an entirely different kettle of fish to one to the housemaster. A visit to the housemaster would most likely result in a stiff scolding and perhaps a detention or two. Being sent to the headmaster, however, almost certainly meant that he was going to be caned. It was an extremely worried teenager that stood up, in almost a trance as he tucked his chair underneath the individual desk before weaving around the room, exiting and softly closing the door behind him.

"I didn't grass you up." Barker immediately told him as soon as they were out of earshot of the classroom.

"I know that." Mycroft impatiently replied, eyebrows raised. Did Barker think he was an idiot?

"I don't know who did, though. Someone reported both of us...you for smoking, me for shagging Sally. Oh God, what's going to happen to us..."

Barker's voice trailed away as the two got closer and closer to the headmaster's door.

"What do you think?" Mycroft hissed, before swallowing. He was fifteen, for god's sake – he wasn't about to let an unconfirmed destiny make him anxious. Reaching out, he knocked on the door – despite his general apathy for people, he had rather good manners and was known as a model pupil. He would never have dreamed of rapping too loudly at the oak of the door.

"Come in!"

A moment of silence allowed Mycroft to reflect on the lecture that had just been given to himself and the now pink-cheeked Barker. He wasn't in that much trouble, himself (though some rather pointed words had been aimed at him about smoking, accompanied by threatening taps of the cane against the desk) – it was mostly Barker, who had taken a good 85% of the shouting. Not only was he in trouble for 'inappropriate actions for one your age' (which Mycroft had had to hide a wry smile at) but also for failure to report Mycroft's own actions.

"B-but, sir – who told you about me and Holmes's discussion?" Barker suddenly asked, breaking the silence tentatively. The headmaster shook his head.

"It is of little importance, so I may as well tell you anyway – young Sally Harper, the daughter of the cook, happened to be passing by the other side of the wall at which you had the discussion to empty some bins, and heard the entire thing."

Barker blanched, and Mycroft remembered the marks on his trousers: they had been only a few hours old, indicating that they had had sex that very morning, before school. Perhaps Barker had done something then...Mycroft held back a smirk as various lewd suggestions came to mind. Forcing himself to concentrate on the rather dire situation at hand, Mycroft looked up at the imposing figure of the headmaster and asked,

"Sir...sir, what is our punishment?"

"Holmes, since you have never been in trouble here, are being let off with a letter home, which you will be given during registration before your final lesson. You're being trusted to take it home yourself, as you're generally so well behaved. Any more reports of smoking, however, and you'll be back in this office feeling very sorry for yourself. As for you, Barker, you will stay for one hour after school every day for the next two weeks and assist the cook in any jobs she has for you. Much like Holmes, if you find yourself in any trouble, you'll find yourself in a very sore state."

Once more, Mycroft tried hard to keep back the smile that was at his lips, relieved that that day was not the day he would meet company with the ultimate sanction. The letter home was rather a bother, though. Before he really registered it, his feet had carried him back to History and he was scribbling away again, mind still on the letter.

"Hello, Mycroft."

"Sherlock."

The mop-haired seven year old looked up at his brother, eyes focusing on the brown envelope that the teen was fiddling between his fingers. "What's that?" he immediately asked.

"Nothing." Mycroft replied instantly, and then inwardly berated himself for responding in such a stereotypically guilty sounding way. Emotion was not an advantage, especially not when talking to his idiot little brother.

"That looks like the envelope they posted home when I punched Ellie Stamford in the face. It was her own fault, of course." Sherlock winced a little when he remembered not the incident, but the result of it – his mother had taken his science kit from him for two whole weeks, with the promise that next time the punishment would be infinitely more dire. Of course, Sherlock could tell she didn't mean it – she loved her sons too much to do much worse to either of them, as had been proven when Mycroft had come home crying quite pathetically the year previously because his glasses had been snatched and broken by a group of rowdier lads at school, and she had stormed straight up to the school and give the headmaster a real earful.

"I said it was nothing!" Mycroft's voice was usually rather severe with Sherlock – despite how much he loved him, he was a royal pain 101% of the time and the little brat deserved it – but this was a whole new level. Low, angry and almost rumbling. Quite different from Mycroft's stereotypical pubescent whine.

"You've been smoking." Sherlock told him after a pause of a few moments when the two walked together the mile long walk from their school. It was a private school, and as such encompassed ages seven to eighteen. Sherlock had attended for just under three months, as it was only now approaching Christmas, and was already well known amongst staff as being, to quote his midterm report, 'an insufferable know it all with zero desire to follow orders'.

"That's a ridiculous suggestion. Why would I smoke?" Mycroft easily asked, glad that he had remembered to slip into easy, slightly incredulous tones to try and convince Sherlock that the notion was stupid.

"You smell like mouthwash and lies, Mycroft. Mike."

It took everything in Mycroft's shallow well of self control not to reach down and give Sherlock the slap that he sorely deserved but no one had given him yet. Yet. Mycroft was quite prepared for Sherlock to get into enough trouble for either the school to use the ultimate sanction, or for their mother or father to snap at one point and lose it with him, Both seemed fairly reasonable assumptions, especially considering Sherlock's annoying habit of turning his deductions into little performances. At seven, he was already far more of a handful than Mycroft had ever been. This thought caused Mycroft to once more nervously finger the envelope in his hands, thinking about its contents.

"Do shut up, Sherlock." a curl of disdain at the lip, a single eyebrow raised...Mycroft's disgusted look had been perfected one long, lonely summer's day in his pre-teen years.

"Are you going to give mummy the letter?" Sherlock's look of curiosity was dangerous.

"Perhaps."

"If you don't, I'll tell her anyway. You told her when I took my science kit back – for a very important experiment, as well – so I'll tell her about this."

Mycroft closed his eyes for a moment, willing himself not to hurt Sherlock, before turning around, grabbing Sherlock by the arm and immediately breaking his will by pushing him against the wall that they were walking alongside, his age extremely beneficial in the circumstance.

"Sherlock, do you remember when you set the old shed on fire and I suggested that lightening had affected it, when really I had seen you doing something stupid with matches?"

As the younger boy writhed beneath Mycroft's pincer-like grip, one hand over his mouth to prevent speaking, he gave a nod, self preservation preventing him from biting Mycroft or worse.

"How about when you broke the sliding glass door and I took the blame for it, and I was grounded for months?"

Again, Sherlock nodded.

"If you tell mummy about this letter, I will tell her all about those instances, and more besides...it's in your best interest not to tell her. Or daddy, either."

There was a pause, before Sherlock nodded again. After a few moments, Mycroft eased his grip from his brother, watching with the tiniest trace of amusement as Sherlock wiped around his mouth and rubbed his wrist and arm, glaring at the red fingerprints on him as if he could burn them off with his eyes.

"I won't tell her." he told his older brother after a few moments. "As long as you don't tell either."

Mycroft nodded, before proffering his hand for a shake, an action ridiculous for a fifteen year old in itself, let alone when in offering to a seven year old. It was even more ridiculous that Sherlock gave a minuscule not of approval at the action before shaking. Within seconds, the letter had been ripped to shreds and stuffed into various cracks in the fence, hardly any paper visible. Brotherly affection was futile. Brotherly blackmail was far more worthwhile.

In fact, Mr and Mrs Holmes may never have found out about Mycroft's illicit (but now, alas, addiction to) smoking had Mycroft been a little more...Mycroft-y and actually read the letter. Right at the bottom was a form to be signed by a parent conceding that the letter had been read. A week after the incident, the two boys had walked into the house to find both of their parents stood just inside from the door. Their mother's arms were folded and a thunderous look was on her face, while their father stood, funnily enough smoking his pipe.

"Mycroft Holmes, how dare you smoke and then not give us a letter from the school?! I am quite frankly astonished that you would do so! You've always been such a good boy! Get inside the house, now – you've got a lot of explaining to do!"

Mycroft was blushing through no choice of his own, and he swung to Sherlock to see a genuine expression of innocence and surprise on his face.

"Sherlock, you go up to your room, now."

The expression of pleasure at Mycroft being properly in trouble for the first time that Mycroft had anticipated to see on Sherlock's face did not appear, despite their already strong rivalry. As Sherlock fled upstairs, Mycroft saw a tiny motion which confirmed what he already knew: a tiny shake of Sherlock's head told him that Sherlock hadn't told their parents.

"Mycroft?"

The teenager looked up from the school work that he had been furiously scribbling away at, from his standing position. "What?" he asked, any attempt at condescension melted from his voice long before.

"I'm sorry you got in trouble at school as well as at home." Sherlock looked slightly anxious and kept glancing around cautiously, as though he was expecting something to hurt him any second.

"Okay." No snarky response, nothing. Mycroft was done. Upon arriving at school the morning after the trouble at home (where he was grounded for a month and his pocket money was withdrawn for the same amount of time to try and eliminate any risk of him buying cigarettes) he had been called to the headmaster's office and caned.

"I don't hate you that much, you know. I'm sorry you ended up getting caught." Sherlock suddenly smirked. "Maybe you should take some lessons in getting trouble from me."

Mycroft managed a tiny smile. "Thank you, Sherlock. I'll keep it in mind."

Although no great exchange had been had, both brothers felt significantly better afterwards.