A/N: Chapter four. Yay. :') Please enjoy, but I don't own Sherlock, k?

Surprisingly, things did not blow up right away. It took nearly a year for Mycroft to notice the difference. For a man who prided himself in seeing the finer details, he (much like his brother) had a tendency to miss the things that were right in his face. Sherlock hadn't even bothered hiding his symptoms because he knew: the best way to hide things from Mycroft was to do so in plain sight. With that in mind, he was guaranteed it would be at least a few months before anyone took notice.

The needles became his dark side and with it cigarettes. He absolutely hated the latter but his system was hooked and, if he decided to stop smoking, hiding the withdrawal symptoms from Mycroft would be nearly impossible. It was actually the smoke that first caught his brother's attention. Not the needles, not the constant trips out, nor the occasional asking for large sums of money. Mycroft was oblivious to all this. But when he came home one day and found himself nearly choking on cigarette smoke, things became blatantly obvious.

"What the hell? Sherlock!" Mycroft yelled up the stairs, fanning the smoke away from his face. He grimaced. There was only one possible perpetrator but surely Sherlock wouldn't smoke. Surely he'd have noticed his brother picking up bad habits like this. Still grimacing, he bolted up the stairs, coughing with each step. Had Sherlock spent the whole day here? How many cigarettes did it take to fill a house with this much smoke? It was a wonder the smoke detectors weren't going off. Then again, they'd probably been dismantled.

"Sherlock, what the hell is wrong with you?" he yelled despite the promises to himself that he would no longer fight with his brother. Since the second fight, their lives hadn't exactly turned back the way he wanted. Now that he thought about it, actually, things really seemed to change around Sherlock's sixteenth birthday. He hadn't paid much mind to it, the slight changes - even the major changes - but now it was in his face and he mentally slapped himself for dismissing this.

"Sherlock!" One more yell and another non-answer. Growling, he lunged for the door, quite surprised to find it ajar. How odd, Sherlock was never one to leave his door open. Privacy was key in their world. This would, however, explain how the smoke had escaped into the rest of the house. He twitched, widening the gap made by the door, and was met with another cloud of smoke, shielding Sherlock from view. Mycroft doubled over, coughing because of the sheer amount of smoke, but Sherlock either didn't care, didn't hear, or didn't see. And the thought that Sherlock wasn't seeing this bothered him. Seeing was key to their observation.

Now that he thought about it, they hadn't done a round of 'right or wrong?' deductions in a little over a year. Guilty as he felt for it, though, this wasn't the time to be bothered by games. Now he was simply worried, worried for Sherlock's wellbeing and frustrated by his brother's actions. He straightened up, using one hand to wave away the smoke as best as he could. Things didn't clear completely but it let him see and breathe better.

He was completely unprepared by what he saw. Laying on his bed was Sherlock, completely oblivious to the world. His eyes were red-rimmed and puffy. Up his bare arms were the telltale signs of needles, many of them, probably used over the course of at least a year. Mycroft shuddered. How did he not notice this? By his brother's side was another needle, completely empty of whatever substance it held. Cigarette butts littered the bed, all (thankfully) unlit except for the one in his mouth. And as Mycroft stared at it all, worry turned to anger and he exploded.

"Sherlock, bloody hell! What were you thinking?" Mycroft screamed at him, reaching out to grip his brother's shoulder. Sherlock turned only a bit, blue eyes unfocussed, a snarl twisted on his features. "What IS this? Are you trying to kill yourself?"

"Not really, no," Sherlock replied. He was startled when the cigarette was ripped from his mouth and tossed at the unfortunately closed window. It bounced off the glass and hit the floor, thankfully not starting the flooring on fire. Shock turned to anger and he sat straight up, barely missing the needle point with his leg, and glared fiercely. "What the hell was that for?"

"What do you mean, what was that for? Sherlock, look around! You're going to bloody well kill yourself if you keep this-" He was cut off abruptly as Sherlock stood up and shoved him backwards. His back hit the wall and the air was knocked out of him, leaving him to simply stare. In any other situation he'd have the upper hand - after all, Sherlock had never been much more than a twig - but this was somehow different. He'd been completely unprepared and he couldn't - wouldn't - bring himself to raise a hand at his brother, even in defence. Never again… he hoped.

The promise obviously didn't apply to his younger brother, who had so easily overpowered him. Sherlock looked absolutely insane. His hands twitched, his eyes gleamed in rage. Mycroft could only wonder exactly how long all of this had been going on. The drugs, the smoking - all of it. How long had he missed the signs? And what would the consequences be?

"Sherlock, you have to stop," he spoke, voice the sort of 'deadly calm' that he knew always got to Sherlock. "All of this. I don't know how long this has been going on…"

"A year. A whole year and you didn't know it, you stupid-"

"…but that's not the point. If you want to stay in this house, you have one year. One damn year. Or the day you turn eighteen will be the very last one you spend in this house. Understood? The smoking goes away. I will get you nicotine patches if it helps. The drugs stop. Not a single needle is allowed to pass over the threshold of this house. You've been warned."

And with that, he turned on his heel and left a very vulnerable Sherlock behind him.

He tried. Honest to God, he actually tried for the first few months. He swapped out cigarettes for nicotine patches, learned to function even better under the influence. But no matter how hard he tried, he was constantly tied to his drug of choice, brought back to the needles by an unquenchable urge. He only ever once tried to stop completely, and that had been terrible. When he wasn't shaking and throwing up from withdrawal symptoms, he was bored.

Boredom was terrible. Boredom was the same as the death of a loved one - to normal people. His brain would stop and it would rot without any indication of what to do to stop it. There simply was never enough of anything to keep him interested. Not enough cases reported in the news, not enough experiments he hadn't done a thousand times, not enough books to keep his interest for long. The only thing that was guaranteed to keep him thinking (and therefore keep him alive and interested in the world around him) was the needle. He hated to admit it, but it gave him everything he needed.

So he tried. But he couldn't bring himself to do it. Mycroft hadn't spoken to him for an entire week after he'd been discovered with the needles and cigarettes but even his brother's disappointment wasn't enough to pull him away. So he took a different route. After the first three months, he stopped trying to quit. The needles, the drugs, they were as necessary as water. He might've said as necessary as food, but, if he'd had a small appetite before, now he had none at all. Food almost literally had to be forced down his throat, and even then he was constantly underweight.

It was far easier than he'd bargained for. Mycroft was constantly checking his room, constantly searching and disposing of everything he found. Sherlock found this a nuisance and quickly found a way around things: he picked the hiding spots far more carefully. If his dear older brother bothered to truly look, he would've discovered the stash hidden in the bottom of the dresser drawers in his very own bedroom, or perhaps he would've noticed the needle or two carefully enclosed in a hollowed out book.

Nearly ten months after their third argument, a third block was pulled from the tower that was the once-strong relationship of Mycroft and Sherlock. The tower began to lean and wobble, ready to fall over at any time. Because Mycroft had left the last ten months up to his brother - for the most part. However, he did not appreciate waking up on the couch and nearly being stabbed by a haphazardly hidden needle captured between the cushion and the back of the couch. He'd actually had to restrain himself from yelling at Sherlock, instead preferring to make some calls.

The first was to a rehab clinic. The best in the country, he was told, nestled in the heart of London. They had on-hand therapists and doctors for every step of the journey, apparently. But this wasn't what worried him at all. What worried him was Sherlock. The damn boy was too smart for his own good; Mycroft had no doubt that the seventeen-year-old would manage to run circles around, and confuse, the therapists. He had to hope this would work.

"Sherlock!" he yelled up the stairs, trying to keep his tone steady. It was surprisingly easy, considering how long he'd spent lying to heads of countries. "Sherlock, do get dressed. And remember your tie this time! I'll have you dropped off at school."

"Why would you do that?" came the muffled reply. Mycroft chose to ignore it and went about his own business as normal, showering and dressing in his finest suit. By the time Sherlock got downstairs, he looked like he'd been awake for hours. Nothing was out of the ordinary at all. He did, however, frown upon seeing his brother.

"Didn't I just tell you to wear a tie?"

"First of all," Sherlock glared, "you're not Mummy. Second, I hate ties. I look better without one."

Mycroft snorted. "Vain, as always."

Sherlock frowned, looking as though he might say something, but Mycroft reached forward and pulled him into an embrace before he could do so. He struggled for a moment, then thankfully relaxed, cautiously putting his pale arms around his brother. They stayed like that for nearly two minutes before breaking away, smiles on their faces that hadn't been there in quite a while. These were smiles that were only reserved for each other.

Sherlock, however, couldn't help but be suspicious. It wasn't as though Mycroft was just being 'nice;' he couldn't place the last time his brother had been like that. Mycroft, on the other hand, turned around and made his way out the door, expecting Sherlock to follow him. He'd been seized by that sudden urge to embrace, just on the off chance that Sherlock would hate him for what was to come.

And hate him he did.

It was worse than that damn Christmas dinner six years back when they'd gotten into an argument over where the turkey had come from. That had been childish. It was worse than the occasional bout of resentfulness over how protective Mycroft happened to be. That was simply… Sherlock. This was far worse.

Mycroft had never known his brother to be the type to kick and scream. Well, he wasn't screaming, but he was definitely kicking and fighting in attempt to stay in the car. And once he was out of the car, things only got worse. It was to the point that Mycroft had to call the two assistants sitting in the car to come and help. They literally had to shove him in the door. The commotion brought on many onlookers and even the people inside the clinic seemed surprised.

Apparently, most people checked themselves in. Well… it wasn't quite the same in this instance, and he couldn't care less. As long as his brother got over the drug abuse and things could go back to normal.

He knew better, though. It wasn't in Sherlock's nature to forgive - the past few years was evidence of this. He'd never forgiven Sherlock, and Sherlock had never truly forgiven him, for the arguments. They'd been so close before, rarely arguing… normally Christmas dinner was the worst time of the year for them both (unfortunately they were always subjected to this dinner; perhaps they were both so resentful because they hated the holiday) and the rest of the year would be good. Not any more.

Mycroft left. As soon as his brother was safely in with the therapist, he turned and he left, not even bothering to visit work that day. He returned to the original Holmes family home, and simply wandered around, glancing at everything. He lingered in his own room and then his brother's, wondering what had changed so much since they were boys.

Of course, he didn't have all day to wander around. Not even close. About three hours after leaving Sherlock in the clinic, he received a panicked call that he'd really and truly expected.

"I don't know how it happened… He… he just jumped out the window! He's insane! Never bring him back! He drove the doctor to tears! Oh my God… he jumped out the window! It was insane!"

Mycroft actually smiled a bit at the call despite himself. At least Sherlock was Sherlock, on drugs or not.

And then he realized: he'd have to go track him down.

Sighing, Mycroft left the house behind for a second time. This time he promised never to look back, promised to never again compare what they used to be to what they were now.

Because things weren't going back to the way they were and he needed to accept it.

But damn did it hurt.