Author's note: Hello everyone :) Here's the second part of the Greenhouse Effect series, hope you like it.

Enojy!

Chapter 1: The watered-down blood we share

One day the world will end. The end will start with fire. Next, there will be floods.

10th January, 2016 – late at night

"It must be a matter of colossal importance, if you have chosen to forego your childish pride and ask for my help. What could it possibly be?"

The room is dimly lit, stuffy and over-heated for Sherlock's taste, although the sweat breaking out in beads along his brow, palms, and the small of his back has little to do with the crackling fire in Mycroft's tackily over-decorated fireplace.

"You know what it is. Even if your minions haven't already informed you of everything the Yarders found, you must have deduced it yourself, so don't be purposefully obtuse, Mycroft. For all your other numerous shortcomings, dullness of mind never counted as one of which I could rightfully accuse you."

There is an extra edge to Sherlock's usually snarky word-stabs as he snarls at his brother, special venom welling up from some sort of agitation (surprisingly) not related to Mycroft. The older man rakes his eyes over his sibling's twitchy from, carefully taking in his fidgeting and unusually prominent perspiration. Ever since Sherlock appeared at his doorstep, the usually flurry of manic energy and bitter tones, and then proceeded to fling himself into an armchair in Mycroft's study, Mycroft hasn't gotten a chance to take a proper look at the Consulting Detective. Of course, that is not to say that he was not able to draw a decent amount of conclusions about the man's state, but the details remained hidden until now.

"Yes, of course. How long has it been?"

"A day."

"What was it?"

"Heroin."

"Not the usual then."

"No."

"Anything else?"

"Horrible quality. That's why the effects were awry, I believe. Also, that might account for some of the symptoms."

"Start from the beginning."

"Isn't that where one usually starts?"

"Now, Sherlock."

Sherlock could swear obeying Mycroft causes actual physical pain, but he does it nonetheless. The beginning then. The air is stuffy with heat as Sherlock starts talking. An hour and a half later, when his voice finally falters and ceases, the air is stuffy with words, positively cluttered with everything that's been said (and that which hasn't).

"Why did you come to me, Sherlock? If my memory serves me, you have always been adamant in your refusal of my assistance regarding this particular matter."

"Will you help or not, Mycroft?"

"Don't I always? I simply wish to know what was it that prompted you to see reason. I may wish to employ a similar tactic in the future. What was it, then?"

"Maybe I just wanted to pester you with my presence."

"I wouldn't be surprised in the least if that were true, but it does seem an unlikely reason, considering the fact that any pleasure you might derive from, as you so aptly put it, pestering me, would be strongly overridden by your own suffering that you so often point out as the main consequence of your intolerance of my company. So, let's try again and this time, if you are so intent on not revealing the real reason, do try to invent a lie that is a smidgeon more convincing. I, too, am bored by mediocrity, so try not to exhibit any. It is rather unbecoming on you, brother dear."

'Very well' Sherlock's mind bites out. Sherlock knows Mycroft has already worked it out, the real reason. But if Mycroft is going to call him out on sentiment, he might as well return the favour.

"Why do you keep doing this, Mycroft? Helping?" Sherlock spits the word out like fish oil he was forced to swallow as a child. Mycroft doesn't miss a beat before answering, his words sliding off his tongue as easily as the said oil off a spoon, and with the same greasy feel to them.

"Your services are invaluable to our country. I can't have you disabled or malfunctioning."

Ringing of the last syllable hasn't died down yet, when Sherlock's contempt-laden words cut in.

"If this is your example of a convincing lie, then it is as successful as your weight-control programme, and considering you've gained half a stone recently, that is not saying much about the plausibility of your statement."

They are in a stale-mate, both acutely aware of the reluctant admissions needed to resolve it. It is only a matter of whose will be the first one to be delivered. In the end, after a relatively short, but definitely charged silence, Mycroft is the first to give in, with a tired sigh barely audible as it passes his lips and wavers like a white flag of surrender. Or perhaps, of an armistice.

"It's what brothers do." The words contain sentiment, although Mycroft's tone is positively flat and devoid of any emotion. It sounds like a line learnt by heart and delivered by a very lousy actor, but Sherlock, who has known Mycroft for a very, very long time, knows the tone is there by design, as a cover. The false indifference of his brother's voice is more telling than the seemingly apparently sentimental content of the actual words.

Of course he knows why Mycroft helps him, time after time. It is for the same reason Sherlock reluctantly (that being rather an understatement) accepts his help, in the end, every time. Sherlock knows, and it would be so easy to simply say the words. Perhaps it would be a first step towards something. Perhaps. But in his current state, with a dark, twisted part of him running wild with need and spite, he remains firmly planted, and the step is never made. He can't resist but throw Mycroft's own words back into the man's face.

"I thought caring wasn't an advantage, Mycroft."

He expects the Iceman, untouchable, even though he hopes his words at least irk the frigid creature a bit. He expects a clever retort or a derisive laugh, but instead, he is met not with the Iceman, or the British Government, or even the grumpy version of his arch-nemesis, but with his older brother.

"It is not, Sherlock. But it is a disadvantage I accept and willingly maintain as a part of my life, when it comes to you."

Mycroft's eyes are tired, but startlingly soft (Sherlock has long stopped associating soft with Mycroft), and there, in a stuffy, panel-and-Persian-rug-covered study Sherlock looks at his brother and sees only that – his brother. They are too similar to ever function properly side by side. They are too similar, and still too different, driven mad by the reflections of their own flaws that they see in each other, and annoyed by their respective ways of handling said flaws, always considering that of the other to be improper. It is absurd, the way both of them would disembowel and quarter anyone who dared cause harm to the other, but how they, personally, never shy from cutting deep into each other. Sherlock will push and insult and aim to hurt, and Mycroft will rise to the challenge, every time. It isn't an occasional friendly jibe or innocuous sibling rivalry – they are both men of exquisite talents to cause harm, and they never spare each other, never grant each other any form of clemency. But they are brothers, and while blood and shared DNA cannot be the only sustenance for affection, when their whole twisted, complicated relationship is stripped down to bare bones, there is the simple truth that they are brothers, and brothers care. Brothers love. It's what brothers do.

"Why?" Sherlock asks, plainly, this time, curious rather than spiteful.

Mycroft smiles slightly, because the "why" brings back memories of a younger voice, equally inquisitive, repeating the same question over and over at the age of three, putting young Mycroft's knowledge to the test.

"Because you are my baby brother, Sherlock. You were that before you were anything else, and you always will be, despite everything, and even when everything else falls away."

"I think you maybe thawing, Mycroft. Your moniker could soon become unfitting. And that's not an answer."

"It is my answer. And now you owe me yours. What makes this time different?"

Sherlock knows truth is the only option at this point in the conversation. He takes twenty seconds to choose his approach, decide what to say, where to start. He has no wish to speak to Mycroft about any of this, but beggars can't be choosers, so he must offer a bit of honesty. He might as well keep his answer as short as possible, spare himself some trouble and go straight to the crux of the matter, which is precisely why he chooses to start his explanation with the one word which could easily make up for the entirety of the answer. 'What makes this time different?' Surely, Mycroft must know. He is still making him say it, though. And knowing him, he won't settle for a single-word answer, either. Arse.

What makes this time different? Obvious.

"John."

An hour and a half later

The room is dimly lit, stuffy and over-heated for Sherlock's taste, although Sherlock's shortness of breath and coarseness of voice have little to do with the heat and slight lack of oxygen, which has been continuously consumed by the fire throughout the course of the evening.

"Sherlock. This will not be easy." Mycroft says, looking directly at his brother, some of his let's-talk-business air surrounding him again. 'Is it ever?' Sherlock thinks. He knows the drill, knows what awaits him, and it makes him weary and tired just thinking about it. Of course, he has no intention of letting Mycroft know that.

"I wish you would refrain from stating the obvious, Mycroft. It just adds to your usual level of tediousness."

Mycroft doesn't even acknowledge the flippancy of his brother's words, his immunity to it so strong by now that it hardly reaches him anymore. Besides, after all that has transpired in the last few hours, he knows flippancy is only a thin thread at which Sherlock can grapple for some illusion of normalcy, and if he were being honest with himself, he is grateful for it, as well (although he has no intention of letting Sherlock know that). They don't do sentiment very often, and when they do engage in the rare practice of being honest and open with each other, both Sherlock and Mycroft are regularly left feeling somewhat off-balance. 'Yes, flippancy is most welcome in this case' Mycroft concludes.

"There is only one more order of business which needs tending to, before you may have your much-needed rest" he says, assessing for the umpteenth time the younger Holmes' dishevelled, dilapidated state.

"Yes, of course." Sherlock almost sighs.

"He won't be kept away, surely you must be aware of that."

"Of course I'm aware, Mycroft. I know that. I know him."

"Yes. But just because you know him, does not make you infallible, nor immune to the mistake of underestimating him. He will find you, even if I try to stop him. For some reason, he doesn't seem as susceptible to my authority as one would expect. Come to think of it, he tends to be surprisingly obstinate. A strange quality in a soldier, really."

"Wrong."

"Beg your pardon?"

"You're wrong. It isn't obstinacy that your eyes-and-ears-in-walls observed, Mycroft."

"Oh? What is it then, pray tell?" A knowing gleam in Mycroft's eye tells Sherlock he's walked right into Mycroft's trap. If it weren't for his current state of utter exhaustion, Sherlock's face would stretch into a small, private smile. Of course, Mycroft would never be wrong. Clever Mycroft, making Sherlock say the words which would bring his point home– trying to keep John away from Sherlock would be as futile as it is idiotic.

"Loyalty", Sherlock answers, because really, if admitting the blatantly obvious truth about John constitutes for being beaten in a verbal duel with Mycroft, then Sherlock is willing to forfeit this fight. Of course, John, loyal John, will never stand for being shut out. There's no point in trying to keep him away.

"That's what it is. Loyalty." 'And maybe (definitely) something else', Sherlock thinks. But he has no intention of letting Mycroft know that.

Mycroft regards him for another moment or two, and then decides to let it all rest for the time being.

"Your room is ready. Get some rest."

In a world where his body isn't battered and bruised and in which his every cell is screaming for things he should not be yearning for, Sherlock would have thought of something snide to say at such a patronising dismissal. In this world, however, he settles for a venomous stare and then hauls himself up to his room, plunking onto the bed, where sleep washes over him, muting the sounds and drowning out the world like a gentle, tepid flood.

Thanks for reading! :) I hope to get the next chapter up in the next few days, no later than Sunday :)