A/N: Thanks to all of you who've read and reviewed this. :) This is the last chapter, guys. It should clear up quite a bit (including "why did Lestrade say 5 years if Sherlock started calling when he was 15?") and I hope you enjoy it. I'll start posting its companion fic tomorrow, if anyone's interested, though that one is so far unnamed. Anyway, please enjoy!

I don't own Sherlock.

"How can you hate hospitals?"

Even as the words left his mouth he realized how stupid they were. No one really liked hospitals, did they? Every wall, every window, every room screamed death and injury. These were buildings filled with protocols that got in the way of love, tight-lipped doctors barely holding up under the pressure, dead, dying, and injured people as well as the worst of all: desperately crying people waiting for loved ones that were never going to be seen again. There were the few happy things about hospitals as well: the gift shops and the people who actually were managing to heal. But besides that… well, Lestrade could sympathize with Sherlock.

"They're boring," Sherlock shrugged at him. Lestrade rolled his eyes. He should've expected this. Of course the kid wasn't going to hate hospitals because of all the heartbreaking, practical reasons. This was a person who'd spent his spare time phoning Scotland Yard and getting high just to keep himself entertained. While most people had a hobby of some sort - fishing, painting, hiking, anything like that - Sherlock preferred to make fools of people and solve crimes. So of course he should've expected an answer like 'they're boring,' because they truly must be to a mind like his.

"It's the same thing, always. So mundane. Everything from the walls to the food are protocol this, protocol that. Everything's on a set schedule. I can't stand it," Sherlock shook his head slowly but stopped at the pain from the concussion he'd forgotten. "Don't stay here for long though."

"What, do you magically get better? Or maybe you charm the nurses into letting you out?" Lestrade asked sarcastically. Sherlock shot him a look that said 'you're a complete and utter idiot' before it struck him. He frowned. "You can't be serious. You… you break out, don't you?"

Sherlock grinned at him, pale hands coming together under his chin. He looked positively pleased with himself, and perhaps a little bit impressed that Lestrade had put everything together. "Of course. It's boring here, so why would I stay?"

"Maybe because you're injured? I mean, really, I hope you're not planning to break out this time."

"And why not?"

"Look at you! You have a concussion, Sherlock. A concussion and a stab wound to the back. You're lucky to be alive, you know that?"

Dark eyes locked on blue, each one determined to force the other into submission. Unfortunately, both possessed quite strong willpower and the room lapsed into silence. The kid was insane, Lestrade decided, absolutely crazy. What kind of person broke out of hospitals because they were bored? Yes, he'd spent enough time in the hospital to have considered breaking out, but he'd never gone through with it. That was just foolish. Sherlock, the arrogant sod, thought he could pull it off and do well from then on. Probably use drugs again to stop the pain.

Finally, Lestrade shook his head and rolled his eyes. He reached out slowly, grabbing Sherlock's wrist in a firm but not overly threatening way. This brought him back to the kid's attention immediately. Smiling mockingly, he declared, "You're not leaving the hospital. Don't even think about it."

"I can if I want to!" Sherlock glared, his gaze positively shooting daggers, but it didn't bother Lestrade in the least. He'd spent enough time dealing with criminals to know better. Reacting to curses and glares would never solve a thing. "You can't keep me here."

"What are you going to do? Send your brother after me? Honestly, Sherlock, look at yourself. You've lost a lot of blood, you're in no state to go anywhere."

"I've been in worse condition and left the hospital," the way he shrugged off Lestrade's comments was positively infuriating. "It's… uh… good that you care and all. Really, nice for you, but I have things to do."

"Like what? Last time I checked you're a nineteen-year-old junkie with no damn future. You're going nowhere and you know it!" Lestrade had had enough. He was glaring right back now, completely forgetting that he was supposed to be ignoring Sherlock's irritating glares and words. Sherlock looked genuinely shocked at this, blue eyes wide, but he remained silent. His eyes moved back and forth rapidly, gears in his mind turning, searching for something to say.

He couldn't come up with a thing. Frustrated, Sherlock dropped his hands into his lap and resumed glaring. His glare intensified when Lestrade's face actually broke into a grin. This was actually kind of funny - after all, Sherlock was nineteen, and a legal adult, no matter how often Lestrade mentally referred to him as 'the kid.' Seeing a grown man sulk in a hospital bed in just the same matter as a five-year-old… it was hilarious, to say the least.

"Oh, for God's sake, Sherlock," Lestrade shook his head slowly, the smile still lingering. "Do you know how much hell you've put me through in the last four years? Without me even having a clue of who you were? And yes, it made things more interesting and exciting, but it wasn't exactly easy to deal with. I get it, this isn't easy either, but you can deal with it. Consider it payback for all of what you put me through. Hiding your identity, sneaking into my house - and yes, I do remember I invited you - calling me late at night, and getting yourself stabbed. This is what you have to suffer through in return. It's not like it's much, so don't sulk."

"Not sulking," came the irritated reply. "I'm not sulking, I'm thinking. What're you going to do to keep me here, then? I've escaped Mycroft's guards before, I can quite easily escape yours."

"Easy. First, I'm going to stay here," the words were out of his mouth before he realized what he was saying. Lestrade hesitated, slightly surprised by himself, but decided it wouldn't hurt to spend his time here. Make sure the kid would get healthy again. Realizing the room had fallen silently, he quickly recovered with, "I'm going to stay here with you, night and day, until you're able to be released. And if you escape, I swear I will have you in a cell by noon that day."

"What if I escape after noon?"

"Uh… what?"

"You said you'll have me in a cell by noon that day. What if I escape after then?"

Lestrade gave an exasperated sigh. "That's not the point, Sherlock! The point is you have to stay here. For your own good."

"I don't particularly care about my own good."

"I noticed. Fine, do it for me then. I don't know what to say. Just… stay here because you need to be."

"Fine." The reply was so quiet it was nearly inaudible, but the accompanying huff was definitely discernible. Lestrade started to smile again, letting go of Sherlock's wrist. The pale man glared and wrenched his wrist towards himself, keeping it protectively close to his chest. Lestrade snorted at this. Another childish behaviour, courtesy of Sherlock Holmes.

"Good, now you're supposed to be resting. Sleep or I'll call the nurses," he threatened lightly, but the kid obliged anyway, blue eyes slipping closed. Sherlock's face wiped clean of emotion and he was asleep within minutes. Lestrade smiled at this image. Yes, the boy looked vulnerable, but he also looked innocent. It also struck him that perhaps Sherlock was hoping he'd leave if he did what he was told, but his plans were quite the contrary. He wouldn't go back on his word. It might be frustrating to stay here (he could already imagine the long week or so ahead) but it would be worth it in the end, wouldn't it?

"Did you really think I was sleeping?" Curious words startled Lestrade back to reality. He rolled his eyes. Trust Sherlock to fake sleep and then wonder if he'd fallen for it. Maybe this was an experiment or something, a way to keep himself entertained.

"Yes." Honesty was the best policy, he supposed. Occasionally, anyway. Sherlock gave a noncommittal hum and shut his eyes again, though this time he didn't bother feigning sleep. Silence passed between them, stretching seconds into minutes and what seemed like hours. Neither slept, though both kept their eyes closed.

"Sherlock?" Lestrade finally spoke, opening his eyes to the world. The room was still relatively dark and he guessed it to be around 7:30. He'd spent the last half hour (or however long it had been) going over things in his mind, and one thing had stayed. Finally he'd simply decided to voice the question replaying itself in his mind. "Sherlock, when… when did you start doing drugs?"

Well. It wasn't the most tactful sentence in the world, but it did get the boy's attention. His eyes opened slowly to reveal a tired-looking blue hue. Quickly his neutral face morphed into a frown and he brought his hands together, tucking them under his chin in the same way he'd done earlier. "Why do you care to know?"

"Well, a few reasons…"

"You want me to get clean."

"I suppose."

Sherlock snorted. "My first time with drugs like this? When I was six."

Lestrade choked on air. It took him a good fifteen seconds to get enough breath back to speak again, but by then the damage had been done. His pause in conversation had been noted. "Six? You can't be serious. You've been addicted since you were six?"

"God no," Sherlock actually looked amuse. Damn him. "I said I first tried it when I was six. Not on purpose, of course, but I was always a bit of a curious child, as my mother would say. My father used to be a bit of an addict. A closet addict, I'm afraid. He got high in secret, when my mother wasn't around, but he couldn't care less about his sons." The monotone way in which he was speaking was just… creepy. "One day, a few weeks after my sixth birthday, he left one of the needles lying around, already full of the drugs he wanted to inject himself with. I can't remember exactly what those drugs were… but that's beside the point. Little me did like to experiment."

"And you… you used the needle on yourself? You've got to be kidding me," Lestrade shook his head in wonder. "A six-year-old? Playing with needles? Most kids hate them, Sherlock-"

"Not me, I suppose. I was raised to be better than that. It was always an accepted fact that pain was weakness, and a Holmes was not supposed to show weakness. I got over any fear of needles quickly. They weren't a match for me at all." He paused, staring off into something only he could see. After a moment, he added, "Almost killed me, of course, considering the concentration in the needle. But my mother found me not two minutes later and it was off to the hospital with us."

Lestrade nodded slowly. It still shocked him. He'd had calls over homeless, addicted children before, and really, it wasn't that bad, as long as they weren't beyond help. But somehow this was worse, far too shocking to know that this genius had been experimenting with substances for so long, that he'd first had an experience with the drugs at so young. And that there was no fear of needles, at all? That was just out of place. Odd.

"Before you ask, I didn't touch them again until I was sixteen," Sherlock informed him, merely shrugging. It was uncanny how he so easily talked about his drug habits, as if they were nothing to worry about at all. "No need to worry that somehow I was a six-year-old junkie. No, that came later. Ten years later, in fact."

"Ever thought about getting clean?" The words were out of his mouth before he realized what he was saying.

Sherlock chuckled. "Sure. I've thought about it before. And I've had my brother try to force it on me."

"But you haven't acted on it?"

"If I did, would I be sitting here with a report in my medical history stating I was brought in high on cocaine with a concussion and a stab wound? Honestly," he shook his head. "What would I do, anyway? The drugs sharpen my mind, they give me something more interesting to do than go through tedious social norms."

Well. He certainly didn't hold back any information on his drug use. Lestrade almost smiled at the irony of this. A druggie willingly going on about his drug history to a cop. "Well, you'll have to find something else to do, then, because you're going to get clean."

Sherlock snorted again. "You don't think my brother's tried that tactic before?"

"This isn't about your brother, this is about you," Lestrade argued back. "You're going to kill yourself with all these drugs. You'll simply have to deal and find something to do or you will quickly find yourself in a cell in Scotland Yard. And I will make sure the charges stick. I'll charge you a million times if I have to."

"You wouldn't."

"Try me."

"What do you suggest for me to do, then? Get a job? Boring. Get a 'normal' hobby? Boring. Get a-"

"Have you ever thought about joining Scotland Yard?" He mentally slapped himself. Really, one would think he'd actually think things through before speaking, but apparently not.

"And what, work with the idiots? With all due respect, Lestrade, you're probably the only one with even part of a brain, and you're still an idiot."

Well. He should be flattered enough that he'd been commented on with 'all due respect.' He stared at the kid, stared hard as he searched his mind for something Sherlock could do. In a few moments, his eyes widened and his face broke into a grin. "I have a proposition, then."

"Go on."

"You're quite better than me with crimes, aren't you? If you can get yourself clean, I can let you in on some of the cases. You could be like… like a detective, I suppose."

"You'll lose your position as soon as your superiors find out you're going to a 'private detective.'"

"Then give yourself another job title. I don't know… be… be a consulting detective, if that's what you want."

Sherlock regarded him carefully for a few moments before his face broke into a grin that mirrored Lestrade's. He nodded slowly, a new light in those intense eyes of his. And that signified it: the beginning of a long road to come. The beginning of everything, from Sherlock's days as a consulting detective to his years being clean.

He would struggle with the drugs for years, but Lestrade was there to help him through whenever he could. When Sherlock finally stopped using completely he was allowed in to help where he was needed and even where he wasn't - keeping the boy entertained was certainly one of Lestrade's priorities.

And many years later, when John Watson waltzed into their lives and changed Sherlock for good, when that selfsame man proclaimed that Lestrade knew the consulting detective better than Watson, he only inwardly smiled and said, "I've known him for five years and no, I don't."

Because that had been the years Sherlock had been clean. That had been the amount of years since he'd stopped referring to Sherlock as 'SH' or 'the boy' and started thinking of him as 'the man.' That had been how long they'd worked together and held a rather odd sort-of friendship.

In truth, they'd known each other well over ten years. But in Lestrade's mind, the moment the man stopped with his drugs the real Sherlock shined through, and that was the moment they truly knew one another.

No one would ever know of the phone calls late at night in those first three years, the disappearing act and shared accommodations in the fourth, nor the night in the hospital sometime in that mix. It would be forever in their minds, a constant reminder of what had happened and what could've been.

Before meeting Lestrade, Sherlock's life had been on a collision course. He surely wouldn't have survived more than a few hours after having been stabbed in the alley. In truth, he owed everything from his title to his life to Lestrade, but there was a tiny, unspoken agreement between them.

No matter what had happened, the past was the past, and it would remain there.

A/N: Well, there we have it. The history of Lestrade and Sherlock's relationship. :) I hope you enjoyed this chapter and the story!