So, it has been ages since I've written anything. I've been reading loads, but I haven't been signed in as I now have a habit of reading from my phone.

I've been reading the original ACD books recently, so please forgive me if my language is slightly Victorian. This chapter is based loosely on Chapter One of The Sign Of The Four, but it won't stay similar for long.

T for drug use. And I don't want to give anything away, but there will be slash. Enjoy :D

Keeping Occupied

John's POV

I woke up in a bed of sweat, panting and shaking as my memories of the Afghanistan war had once again decided to haunt my dreams. There was no light creeping in from behind my curtain, so it was night. Knowing there was no way I could get back to sleep now despite having work in the morning, I got out of bed and began my descent of the stairs, my original intention being to make myself a good cup of coffee.

At this point, I didn't know whether Sherlock was up or out or, unlikely as it was, asleep. I didn't really know what he got up to during the hours when I was getting some shut eye, apart from playing that stupid violin of his at ridiculous hours of the morning. I had assumed that he merely got on with his experiments; possibly some of the ones that Mrs Hudson and I would disapprove of if we were awake. It came as rather a large shock, then, to find my companion sitting on his armchair, holding a hypodermic syringe to his left forearm with a look of intense concentration on his face as he slowly pushed whatever was in there into one of his veins.

"Sherlock!" I cried, surprised at the little jump he did – he was obviously deep in concentration and hadn't been expecting me to walk in on him at this time.

"I'm busy, John." He replied without looking up at me, pulling the needle out and picking up a tissue to mop up the tiny droplets of blood delicately oozing out of his arm.

"What are you doing?" I demanded, rushing over to check that he was okay. His pupils seemed fine, and he wasn't sweating at all. The thing that worried me most was that there seemed to be countless other tiny scars on his forearm that I'd never noticed before.

"John, there's no need to worry. It's only a seven percent solution of cocaine."

"Cocaine?" He said it so casually that I couldn't conceal my surprise, and to be quite honest, disgust. As a doctor, it's my job to know that illegal, Class A substances are bad for you. Anybody over the age of eleven should know that. Of all people, Sherlock should be extremely careful not to damage his brain if he could avoid it. I hoped that it was another one of his holes of knowledge, and that a brief description of some of the adverse side effects would set him straight.

"Sherlock, that stuff… It can be really bad for you. It mucks up people's minds! Kills people even!"

"John, I'm a chemist. And a rather good one if I do say so myself. If you think that I am ignorant as to the effects of Cocaine Benzoylmethylecgonine, then you must be more of an idiot that I originally thought. I have been taking this stuff between cases for years, and I know the right dosage for me to achieve optimum effect whilst refraining from causing any damage. As a doctor, I trust you also know the positive side effects of the drug in question?"

"Well, yes. It stimulates the mind and gives you a short burst of energy."

"Exactly. Right now, I have no case to be working on. My mind rebels at stagnation, John, and at times like this, cocaine is the only thing that keeps me sane. I'm sure you can understand that."

"But-"

"No buts, John. Unless you can find me something suitably challenging to occupy my mind, any argument of yours remains invalid."

I couldn't think of a reasonable reply to that, and so walked to the kitchen tutting and muttering disapprovingly. I assumed that Sherlock wouldn't be needing a coffee; supposedly he'd had enough of a boost already. Sure enough, when I made my way back to the living room, Sherlock was sitting up completely straight, his hands steepled under his chin and his eyes wide open with a rare grin on his face. I couldn't help but smile in spite of myself at how happy and contented he looked – it was obvious to anyone that Sherlock would literally go crazy if his mind wasn't stimulated to a suitable level at all times. I, as his flatmate and best friend should have realised this earlier. I shook my head, still smiling, and sat down on the sofa. I noticed that Sherlock was watching me, and after taking a gulp from my steaming coffee, I realised I was curious about what cocaine was really like.

"What's it like?"

"Hmm?"

"Cocaine. Compare it to caffeine." I thought this would be a relatively easy to understand comparison.

"More potent. Much more potent," His voice was almost a hum. "And… I don't know how to describe it - it's just better in every way. Apart from the crash, which is about… Six times worse."

This seemed perfectly reasonable and exactly what I was expecting. I took another mouthful of coffee.

"Do you want to try some?"

And I immediately spluttered it right back out all over Mrs Hudson's carpet. I hoped she wouldn't mind.

"What?" I wasn't sure I'd heard correctly, and if I had, I don't think I would have been any less confused.

"Would you like to try some of my cocaine? I won't charge you."
I'd heard right. "No! Sherlock, I just found out that my flatmate takes cocaine on a regular basis. That was enough of a shock. Now you're offering me some, just as casually as if you were offering me a softmint! That isn't right, Sherlock."

"John, I merely thought you might want to experience the effects first hand, you're overreacting."

I shook my head but remained silent, not in the mood for an argument that I would inevitably lose. Realising I didn't know what the time was, I checked my phone. 03:25 apparently. I groaned, not wanting to have to spend four and a half hours in an awkward silence with my, now high, flatmate. I announced that I was going to have a shower, and walked to the bathroom.

After emerging from the shower and going up to my room to read for a few hours, I left for work. I cheerfully bade goodbye to Sherlock on my way out, hoping to seem as though I had quite happily forgotten the whole ordeal with the cocaine. I hadn't. I could recall what he had said, or, as it sounded in my head, challenged me at the time;

"Unless you can find me something suitably challenging to occupy my mind, any argument of yours remains invalid."

And that is exactly what I planned on doing – finding something "suitably challenging" to occupy Sherlock. I hadn't come up with anything yet, as such, but I had ruled out a few possibilities, including faking crimes of any kind – he'd see through me in a flash. I also ruled out somehow inducing a crime or two, because, well, that was just plain wrong. I'd considered buying him a Rubik's Cube, but decided against it because I was sure that it would seem pointless and dull to him, and he'd solve it in a matter of seconds anyway.

It was, thankfully, a boring day at the surgery. There were a few cases of flu in which I had to reassure several people that the chances of them dying were, in fact, very low. There were a few routine checkups I had to go through, despite everyone being of perfect health, and there were one or two people with bad bruising but hadn't broken anything. However, my day personally had been very unproductive. I couldn't think of a single thing to get Sherlock off the drugs. I was very determined, but I didn't have a clue, so I decided to give Lestrade a text, asking to meet up in the local pub later.

A/N: So, what did you think? Please review - it has been so long since I have written anything so I need some feedback :D

I'll try to post as frequently as possible but I'm quite busy, so I don't know when the next chapter will be. Hopefully before Monday :)

At least I know where this is going. I hope. But who knows? Anyway, enough rambling. If you review I will reply and everyone will be happy and YAY RAINBOWS now go review :D