Note: This is the first chapter of a fully-fleshed work that's been living in my head for a very long time. If there is any interest, I will continue it. So please, let me know what you think. I welcome all criticism.

xxx

When John got home that evening, Sherlock's coat was in a crumpled heap on the floor of the kitchen. Slamming the contents of his pocket onto the counter in a jingling mess, John frowned thickly. Bad enough Sherlock insisted on wearing that blasted wool overcoat through the hottest July London had seen in fifty years, but the fact that John had trekked all the way up to bloody Ikea just last week to purchase - on his own heard-earned tab, he might loudly add - an over-the-door coat hook specifically to solve this ongoing coat-on-the-floor issue. Well, it was too much. John drew an intake of breathe and turned toward Sherlock's bedroom, ready to shout through the wall at his flatmate.

Instead, he coughed in surprise.

It was not Sherlock's coat in a crumpled heap on the floor of the kitchen. It was Sherlock. His eyes were not open, but they weren't entirely closed either - an unseeing crescent of silver glistened through his lashes. His right arm and shoulder sprawled out of his coat, and under him, shirtsleeve rolled and a telling red tourniquet bound around his sinewy arm. A syringe and an overturned vial laid not far away. A sheer line of dried drool or vomit crusted the side of his cheek. So he had been like this for a while. John's heart lunged for half a second before slipping into the alert calm of a medical professional.

He squatted on his heels. After loosening the tourniquet, he slipped his thumb and index finger around Sherlock's wrist. The pulse was there, frantic and faint, but there nonetheless. He needed an ambulance. John patted the pockets of his trousers for his phone.

"Fuck's sake." John glanced up at the counter, where his keys, mobile and loose change had landed moments ago. His bad leg protested as he fumbled to his feet. Teeth gritted, he let out a curse, reverberating harshly throughout the flat.

At this, Sherlock stirred.

"No ambulance. Lestrade...", Sherlock begged n a voice that was halfway between a gagging cough and a whisper. He made a pathetic effort to accomplish something like sitting upright.

John's thumb hovered over the pre-programed button for emergency services. "You've overdosed, you sodding idiot. You need more help than I can give you here-"

"There's a mug in the cupboard which I've lined with dioxin capable of transdermal intoxication. Call and I won't tell you which one." His voice was still ragged but it was sounding more like Sherlock. This might very well be the first time in their tenure as flatmates that John had been glad to hear that posh, measured, rapid-fire arrogance.

"Thanks for the warning, mate," John shot back sarcastically, striding over to Sherlock, hovering over him. "I guess there's another trip to the Ikea housewares department in my future. Didn't think I'd need to be keeping my tableware under lock and key, but -"

"I didn't overdose." Sherlock said firmly, a tone of realization in his voice. Through the humming, darkened blur of his vision, Sherlock shifted his head and attempted to focus. A pungent dark spatter on the suede of John's left loafer - cooking oil - peanut - a southeast Asian variety - so he'd accompanied Emma to her Thai cooking class this evening - perhaps things were over with Caroline, then - no, no, no. Sherlock closed his eyes, struggling to push the torrent of irrelevant deductions aside. He hadn't overdosed. Of course he hadn't. He hadn't even shot up yet. What then? Pulse markedly rapid, mild edema of the tongue, throbbing head, acute nausea, vision swarming with pin pricks of light, almost certainly attributable to low blood pressure. "Simple dehydration. Bring me a glass of water, John."

"You just told me-"

"Did you not hear me or did you simply not process it in that exceedingly normal brain of yours? The glasses are safe. Just don't touch the mugs."

John turned the tap, grabbing his keychain torch as the glass filled. Thrusting the glass into Sherlock's hand, John flicked on the torch. "Eyes at me." Sherlock's pale green eyes dilated obediently in response to the light.

"I didn't hit my head." The screaming ache of his shoulder and elbow told him he'd at least had avoided that much. Better the transport than the brain.

Satisfied, John flicked off the light and helped Sherlock into a sitting position, removing the bulky coat as he went. Sherlock leaned weakly into John's hand, and John noticed with a start how palpable his spine and ribcage were though his shirt. Scarcely a trace of any padding - fat nor muscle. Not that it should have shocked him, as long as he'd known him, Sherlock had been underweight by any measure. The man ate less than a toddler. But he hadn't cause to see much, given Sherlock's unwavering attachment to that damn coat. But now John noticed how sunken and tired his face appeared - had he always been able to see Sherlock's upper gum-line through his hollow cheek? He didn't think so. But that was irrelevant now, as Sherlock was gulping down the contents of the glass in breathless swallows. "Sherlock, you might want to ease up -"

Sherlock slapped down the empty glass triumphantly and scowled at John. "I'll be fine, I just need -" Sherlock suddenly jerked forward with a deep retch. John automatically positioned his other hand on Sherlock's abdomen, steadying him on either side as he vomited a thin, watery mixture of water and stomach acid. John winced. When nothing was left Sherlock continue to dry heave.. Hands on either side of Sherlock's torso, he could feel the thin sheath of abdominal muscles quivering with the effort of ejecting the emptiness that Sherlock's stomach held. He was too thin, much too thin. Emaciated. When John felt his thumb hook into the underside of Sherlock's ribcage, Sherlock slapped his hands away with surprising force. He slumped to the floor, panting. "Let's try that again."

"Right. I'll ring the ambulance."

"No!" Sherlock jolted upright and looked threateningly like he was attempt to stand. "if you do that, I'll never work again. Lestrade - "

"What does Lestrade...? If this is about the drugs bust, nobody needs to know. That is the least of my concerns. You very clearly haven't been taking care of yourself and - "

"John," Sherlock said. No, he pleaded it. In a very un-Sherlock way. "Please, John. I assure you that this will not happen again." It should have never happened in the first place, after all. He'd been careless.

Everything in John's head - the part where twentry-three combined years of clinical training and experience lived, told him that Sherlock needed help. That this condition, whatever it was, required hospitalisation. But then, Sherlock was John's friend, and John's friends lived somewhere that wasn't his head. Furthermore, it was Sherlock Holmes. And Sherlock Holmes was not typical, as a patient or as a person. John slipped his phone into his pocket. "I'm going to make a chicken broth tonight. You're going to drink it and keep it down." If he could get electrolytes and hydration into him, the immediate danger should pass.

Sherlock gave the slightest of nods and took John's offered hand. Still too weak to stand, let alone walk, Sherlock leaned into his flatmate as his body was half carried, half dragged to the sofa.

If this was to work - this time, finally, after so many failures, Sherlock would have to be more careful. Focused, unwavering, and as thin as the beam of a laser.