Author's Note: I've been wanting to explore Mycroft's character again, and it occurred to me that the scene at the morgue between Sherlock and his brother in "A Scandal in Belgravia" (and Mycroft's subsequent phone call to John) implies a lot more than we ever really hear in detail. When did John find out that Sherlock has his 'danger nights'?

Also features a rather puzzled Mycroft, who I think, even at the end of season two, is still surprised by the unwavering loyalty and raw strength of Doctor John Watson.

Many happy readings, and any thoughts you could leave are always, always appreciated. :)

His Brother's Keeper

Part I: Recollection

"Just the one."

Mycroft held out the single temptation between gloved thumb and forefinger, his glance roaming carefully between it and his brother. He waited.

"Why?" Sherlock's tone was sharp, verging on suspicious.

Irony served as well as anything to mask Mycroft's intentions. "Merry Christmas."

Sherlock responded with a sound of dark amusement as he reached for the cigarette, and Mycroft looked down, searching for the silver lighter in his pocket and taking advantage of the shadows on his face to re-establish his semblance of neutrality. He didn't think his expression had slipped, but he was not about to take chances. One didn't take chances with Sherlock.

He feigned composure, even complacency, during the next few minutes, watching as his brother released slow breaths of smoke into the cold, sharp air of the hospital hallway in between words. Their voices, soft and equally cold, echoed in the stillness, and he wondered, not for the first time, how they could possibly be so alike and yet forever on opposite sides of the same vast plane. Brothers, striving against each other for meaningless dominance, burying true emotion under a lead blanket of petty feuding and unsubtle resentment. The thought had crossed Mycroft's mind, once, that Sherlock, for all his faults, might have at one time been a reflection of what his older brother could have become, had Mycroft chosen a less worldly path to walk. Pointless musings, in the end.

Sherlock turned on his heel a moment later, carelessly flicking a sprinkle of ash from the cigarette, the angle of which was oddly delicate between his fingers. Mycroft knew that the conversation had been nearly over, though; they could only stand so much of each other's presence. He raised his chin slightly as his brother's unexpected "Merry Christmas, Mycroft" echoed back down the length of the dim hallway.

But that was Sherlock, after all. To expect the unexpected was not the most ideal method of dealing with him, but it was as close as anyone could get.

Mycroft frowned. Anyone, that is, except John Watson.

He waited until the door had swung shut behind Sherlock, but no longer, before quickly pulling his mobile from his jacket pocket. Mycroft had many phone numbers on speed-dial, but John's was one of the few he had also taken the time to memorise thoroughly.

Brows drawn low, he contemplated that for a moment as he listened to the dial-tone on the other end of the phone. John Watson. Doctor, ex-soldier, moral man, stubborn, firmly planted in reality. Average, in all ways but one: He was the friend – yes, friend – of Sherlock Holmes, and that terribly strange happening still puzzled Mycroft beyond belief. He rarely put events down to coincidence, but nor did he believe in that extraordinary human concoction known as fate. John's place in the life story of Sherlock seemed to be hanging somewhere in between the two, which was, to Mycroft's precise and well-organised mind, exceedingly presumptuous of it.

"He's on his way; have you found anything?"

"No. Did he take the cigarette?"

Mycroft could hear the barely-concealed agitation in John's voice, and let out a resigned breath of an answer. "Yes."

"Shit," John said softly, and right at the moment, Mycroft could hardly have agreed more.

It was not the first time this had happened, and he knew it would not be the last. Sherlock was a man of keen intelligence and remarkable discipline, but he was also a man of few virtues and many vices, and it was on this latter score that Mycroft's thought was now bent; for he knew, both through instinct and the evidence of his own senses, that his brother's self-control was teetering on the breaking point. It would take very little to send him over the edge tonight.

Which was, he mused, all the more reason why John Watson had quite suddenly become the weight that was anchoring Sherlock, the single strong point that would not yield, however reluctant John was to play the part. Even in the face of Sherlock at his most unmanageable, the doctor's loyalty remained firm. He would weather the storm, he would not break, and he was bound and determined that Sherlock would not falter, either. Mycroft knew the power of loyalty, but in the case of John Watson, he found himself still at something of a loss. The doctor was, in many ways, still a mystery to him after all this time – a strange combination of emotion and common sense, of confusion and fearlessness, a melding of the ordinary and the extraordinary.

He remembered, with a slight burning of distaste, the first time he had been forced to pull John aside and explain to him the matters that Sherlock had not bothered (or conveniently forgotten) to mention: the narcotics, or rather, the desperation that drove him to them. John had been aware from the start that his flatmate kept a number of peculiar habits, nicotine patches being one of them, but it was just as obvious that no one had warned him that the addiction came with a higher price, when Sherlock's control floundered and the spark of his restraint went out, leaving him in darkness.

For there was darkness in Sherlock. He had never actively tried to hide it, but Mycroft suspected that John, still full of wonderment at the brilliance if eccentricity of his companion, did not care to look too closely for it.

It was Inspector Lestrade who made the call, though, at quarter to midnight after a day that had seen a fine sprinkling of February snow and far too many headaches for Mycroft to imagine that his mobile ringing shrilly at this hour could portend anything but mild disaster. He pressed his lips together and answered it.


"We might have a bit of a problem," came Lestrade's voice immediately, tensely, "and, yeah, its name is Sherlock."

Wearily, Mycroft closed his eyes and massaged a hand over his temple. "What's he done this time and when should I start worrying about it? Is tomorrow soon enough?"

"I don't think we've got till tomorrow. I'm not worried about what he's done, more like what he might do. He's got that – OK, you know that case he's been obsessing about for the past two days? The Buckley one, yeah. Well, it's not going too – it's not going at all anymore, actually."

Something in the Inspector's tone caused Mycroft to snap his eyes open again. "Meaning what, exactly?" he asked, brow furrowed as he began to anticipate the answer. "Am I to understand that my brother did not bring this one to a successful conclusion?"

"Nope. Bastard got one second ahead of us and jumped right off the Hungerford about an hour ago. Took two bystanders with him, too – shot – when they tried to move in. We got the body, God knows it's not much help to anyone now."

This time, Mycroft remained quiet, pacing an agitated half-circle toward the darkened window of his study and staring out into the night, through which he could see tiny cold flakes still drifting. He had no particular like or dislike of snow, but its presence certainly did add an aura of gloom to the already unpromising circumstances.

Lestrade apparently took his silence as agreement, for he went on tersely, "Anyway, Sherlock's got that look – that sort of vacant one, you know – and I don't think he's gonna hold out much longer." A pause, eloquent in its implications. "I'm on duty tonight. Someone really needs to be there."

The lines on Mycroft's forehead deepened. "He has Doctor Watson – "

"Yeah, but I don't think John really gets it, yet. He's still working Sherlock out."

"How long has it been?"

"Since they – oh, right, since the last time? I'd say a month and a half, at least. I think it was that thing in Kent just after Christmas that set him off."

A few quick calculations ran through Mycroft's head, and his grip on his phone tightened unconsciously. Too long. There were cycles to these things, he had come to realise over many years, even if they were only visible in retrospect. It was the slow building up of pressure, the minute stress fractures in Sherlock's mind that were blatantly ignored until they broke apart all at once in a fit of frustration, and then Sherlock would try to lose himself, drown his overactive mind in a pool of artificial numbness.

"How bad is he?" he asked quietly.

"I've seen him worse, but I've seen a hell of a lot better, too."

A number of choice words, all short and none of them polite, occurred to Mycroft at this point, but he said none of them aloud. Instead, he turned abruptly on his heel and walked rapidly towards the door, his eyes and mouth set stone-like in his face.

"In that case, I'd better let Doctor Watson know the sort of night he's in for."

So, this became longer than I meant it to. I, therefore, as the sole power behind this story, can leave you in suspense!

On a brighter note, reviews just make my day. :)