Wrote this forever ago (by which I actually mean like four months, haha) when I was still just messing about with characterisation and coming up with plot ideas. This was mostly me trying to figure out if my personal drug experiences would work with Sherlock or not. It's a little pointless and stupid but hey.

I was originally going to just let this rot in a folder somewhere, but I stumbled across it again today and thought ehh what the hell I might as well post it. It'll complete my set of Sherlock-getting-high-on-stimulants fics if nothing else. Already got nicotine and cocaine, after all, so here's speed! Always good to have a theme, right?

[NOTE: This doesn't have anything to do with my overarching fic universe, having been written weeks before I came up with the plot of Can't Rewind Now. It's in its own little bubble in terms of history, so if you're a regular reader of my stuff just throw out everything you know about my headcanon before reading. Cheers!]

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Cocaine was always preferable, of course. Always, always. But not always available. He supposed he should have known beforehand that the dealer was unreliable. She'd been sloppy, set up too many points of contact and never took his advice when he told her which were cops. Probably rotting in a cell somewhere by now. Well, he'd told her so.

Cocaine was always preferable but alternatives were always available. Sherlock didn't hold much flak with the recent so-called epidemic of ADHD diagnoses sweeping the developed world. Sensationalist talk of food additives and pollution. More likely the increased demands of modern life simply rendered the affected parties more easily identified. Whatever the cause, he welcomed it. Welcomed the hordes of schoolchildren going to and fro with bottles of drugs in their knapsacks. They rarely tried to haggle. All Sherlock ever had to do was wave a few crinkled notes in their faces. Half a bottle of Ritalin, six or seven Dexedrine tablets. It was all the same, in the end. Stimulants, dopamine. Calm.

And oh god, was he calm. It must have been amphetamines that boy had, he surmises languidly. Dextro. Perhaps even Adderall, he wasn't sure. His mouth feels like he's eaten a packet of cotton balls and his stomach is a hollow pit sitting sour in his abdomen. None of it matters, though, because for the first time in what feels like ages (really only a day or two at most, he knows, but honestly who cares) he's finally still. He lies absolutely motionless on the cool grass of one of the city's parks, stares into an endless abyss of twinkling night sky and thinks of nothing.

The stillness won't last, he knows. Sooner or later the extended-release mechanism of whatever pills he's just taken will kick in. It'll almost certainly be too much, and he'll be high, high, high until it wears off again. He could stave it off by eating something, maybe, but that would require moving. Moving will only get his blood flowing faster, will only make the drug work faster and so, really, logically, it's better to lie still. Lie still and enjoy the calm while it lasts.

It's less than ten minutes. His thoughts (when had he started thinking again?) are drifting along at a leisurely pace. Idle musings on constellations and stars and the relative intensity of light pollution. And then a word catches.

They call it light pollution, he was thinking to himself, all grave like it's such a terrible thing. But what does it actually matter? It's hardly permanent, not like real proper pollution. And of course the stars are all still there, just hidden.

… hidden.

Hidden. Hidden... hidden... oh for fuck's sake... hidden...

And just like that, the glorious moment of motionlessness is broken. He bites out an angry sigh and brings his hands up to cover his face as if blocking out the source of the thought will stop it. It doesn't, of course. The stuck word just keeps looping around inside his head like a broken record. Never impeding his thoughts, just existing. A kernel of stupid, meaningless repetition that layers over and under and behind and fills up all the blissful empty spaces. Like his brain is punishing him for daring to go five minutes without cognating.

Why did this always have to happen? Why could he never just have the calm? Have the silence last and last forever without being ruined by misfiring neurons and his own freakish brain's hateful aversion to quiet?

… hidden... hidden...hidden...

"Oh shut up!" he snaps to himself. Won't work. Never works. At best he might get himself stuck on a different phrase, but the metronomic beat will stay.

… hidden... hidden...

This never happens with cocaine. Or Ritalin. Or anything besides stupid bloody amphetamines. Stupid amphetamines that make his hands tremble and his head twitch and his brain get stuck on words. And why did it always have to happen with the stupidest words? He can never get trapped repeating a sonata, or a series of useful formulas. No, his moronic trainwreck of a genius brain just latches on to whatever syllables happen to be floating past at the moment when the switch gets tripped. And there he's trapped. Over and over until it stops of its own accord.

… hidden... hidden... fucking hell just... hidden...

Growling, he sits up and digs a slightly squashed packet of cigarettes out of his coat pocket. Nicotine will help. Probably.

His hands shake as he plucks one from the cardboard and fishes out his lighter. Getting the stupid fiddly stick alight proves to be a bit tricky when his head refuses to stop moving, but he manages. Always manages. His head jerks to the side again as he tucks the lighter away, sending cigarette ash scattering all over his clothes and he thinks he should brush it off but what's the point? His head will only twitch again.

… hidden... hidden... hidden...

"Just give it a rest alread- alre- alread- fuck."

Stuttering. He loathes stuttering. It never lasts long but it always seems to represent some kind of horrible breakdown in communication between his mind and body. Words that he knows he can say get choked off before they can form through no action of his own. It's like his mouth just refuses to finish them and it's awful and stupid but the more he tries to push his way past it through sheer willpower the worse it gets.

"I'm fine," he says suddenly. He's not, not really. That 'f' had been this close to sticking. He knows if he tried anything with more than a single syllable it wouldn't come out right. But the cigarette is helping with the tremors and at least his head isn't twitching so badly. He thinks he could probably manage standing. Standing and finding a shop.

It's a Tesco and it's blessedly close to empty. The only other customer is a rumpled-looking man with a military haircut and the scars and muscle habits of a left-handed doctor. Surgeon. He's picking up a packet of biscuits and a drink, trying to calm his nerves because it's his last- no, second to last day of leave before a foreign tour and he can't sleep. Already seen action, then. Knows where he's going and what he'll see and Sherlock forces himself to stop.

Counting the change in his pockets is something safe and normal so Sherlock does that instead. The combat medic gives him a sidelong glance and Sherlock turns away to look at the ice cream display, only to wince when he catches sight of himself in the reflective surface of the glass freezer doors. He's a mess, as usual. Hair sticking up in all directions, dark circles under his eyes and cheekbones jutting out like a skeleton's. The clothes Mycroft insisted on buying for him last Christmas are frayed and too loose. (Just a button-up and jeans, now, because he sold the jacket and the coat was too heavy for summer so he left it on a bench somewhere and forgot. Mycroft will probably try to get him new ones. Have to be on the lookout for black towncars.)

The medic is giving him a look and Sherlock can see it in the door reflection so he whirls around suddenly and glares. His head twitches at exactly the wrong moment and ruins the imposing effect he was going for. Luckily 'crazed drug addict' is just as good a deterrent as anything else and with a slight roll of his eyes the man turns and walks away. Probably thinking I'm a lost cause, Sherlock thinks. Good. I am.

He gives the soldier a good few minutes to get out of the shop before scooping up a random selection of crisps and a bottle of water and leaving himself. Eating is really the last thing he wants to do right now but he knows the twitching and the stuttering won't stop until he gets some food in his stomach. Better to suffer through a packet of crisps than pass out in an alley again (even if that would be a good way to test his theory about Mycroft planting a tracking chip on him during the last hospital stay).

Three packets of crisps, another cigarette and half a bottle of water later he's feeling much closer to normal. There's enough of a buzz left over to keep him content with the low hum of London's early hours so he stretches his legs out in front of where he's sat on the kerb and leans back to regard the pale sky. The stars are hidden. Not by light pollution but by the creeping rays of the sun.

"Looks like more nice weather."

Sherlock startles badly at the voice and whips his head around quickly enough to make it twitch again. The military man is sitting on a bench to the right of the shop doors, apparently having been there all this time. Sherlock hadn't even noticed. He glares.

"Sorry," the man says as he crumples up his empty biscuit packet, "didn't mean to startle you."

"I wasn't startled," Sherlock asserts hotly.

"Alright," the man smiles. He tosses his litter into the bin next to him and leans forward as if to stand. Sherlock hopes he'll leave. Instead, he speaks again.

"There's... places to go, you know. For help. Any clinic-"

"Fuck off," Sherlock snaps. The man raises his hands in a placating gesture and smiles that irritatingly patient smile again. Sherlock flips him a rude gesture and the man finally gets up and walks away, shaking his head. What a waste, he must be thinking. Sherlock scowls and hopes the man gets himself shot in Iraq.

For all his venom, though, he can't quite bring himself to hope the man dies.