John glanced up from the television and grimaced as he took in Sherlock's bruised face and dishevelled clothing. His shirt was torn in several places, and the black fabric clung suspiciously to his skin. The faint copper odour that hit his nostrils as Sherlock came close enough to glance at the screen and then roll his eyes at the programme John had been watching was unmistakable.

"Is any of that blood yours?" he asked as he rose and went to the kitchen for a large bin bag.

Sherlock glanced at his self with disinterest. "Some of it."

John ruffled the bag and held it open as Sherlock began to disrobe. There were several faint red patches marring his skin and a long tear that started at the cap of his shoulder and drifted down nearly to his elbow. "That's a nasty slice." He peered closer. "Curved blade?"

There was something akin to pride in Sherlock's bright gaze as he nodded. "Meat hook. The other two had flick knives. But the real distraction was the one with the broken bottle. You're not going to give me a lecture about going to Casualty, are you?"

John shook his head. "No. Not after the last time. I'm still stinging from the telling off that nursing supervisor gave me."

Sherlock chuckled and then clutched at his ribcage and winced. "Don't dawdle, John. I have work to do."

John made an 'after you' gesture and pointed at the bathroom door. "Other than the punch in the face, did you take any blows to the head?"

"Not that I remember." Sherlock picked a piece of glass out of his hair and John glowered at him before double checking the size and reactivity of his pupils.

Satisfied Sherlock wouldn't pass out whilst he was showering, John said, "Get cleaned up. I'll go get my kit."

When he'd left his army days behind him, John thought that his tour of the operating theatre was over as well. Taking up with Sherlock Holmes had made him think again. Within days of settling in at 221B Baker Street, he decided that perhaps it would be better to be safe rather than sorry, so he'd ordered up a field medical kit of the type favoured by extreme outdoor enthusiasts and then supplemented it with instruments requisitioned from Barts. Now, if he needed to, he could take care of an eyebrow raising number of medical emergencies, and no one would be the wiser.

He cleared the table of the usual accumulation of newspapers, unread mail and other sundry items, unrolled his surgical kit, selected and disinfected the necessary instruments, and then prepared syringes of the drugs he would need. When everything was ready, he made a pot of cocoa. Sherlock would protest, he favoured coffee, but occasionally John did get to draw a line.

The shower cut off and Sherlock emerged from the bathroom wrapped in a towel. It was clear he was feeling injuries he'd neglected to report. John tipped his head. Sherlock's lips thinned into an expression of annoyance, but he dropped the towel to the floor and stood obediently for John's examination. Toe strikes and boot-print shaped bruises nearly clear enough to size the wearer were beginning to bloom on his torso.

"You didn't mention you took a kicking," John commented as he bent to get a closer look. He got a shrug and a wince in reply. Like those Sherlock had defeated, the injuries were unworthy of comment. He ran his fingers over Sherlock's skin, probing carefully for tender spots that might suggest internal injuries. He was relieved to find nothing of concern. "Raise your arms." John fitted the earpieces of a stethoscope and watched as gingerly Sherlock raised first the left arm and then even more carefully, the lacerated right above his head. "Take a breath. And another." He moved the head to a new spot and said, "Again."

"Stop fussing."

"I'm not fussing. I'm making sure you don't get a rib through your lung."

"Will I?"

John listened one more time for good measure. He'd rather an X-ray to be on the safe side, but he knew he'd not get it. The breath sounds had been normal. Sherlock's heartbeat strong and regular. "Probably not. Come on. Let's get that arm seen to."

John gestured at the chair and as Sherlock gingerly settled he pulled on a pair of gloves. Washing had caused fresh blood to seep and crimson rivulets trickled down the length of Sherlock's arm. "Hold that." He handed Sherlock a towel to spare the floor and Mrs Hudson, and then concentrated on cleaning the wound properly, syringing it out with disinfectant laced water until he was sure there was no chance of any dirt being left behind. "You need stitches."

Sherlock didn't react as he readied the needle and then slipped it under his skin to inject the anaesthetic. He set the syringe aside, dabbed at the blood that continued to collect along the edges of the wound and then after a minute or so had passed and the skin had a chance to numb, he injected the antibiotic. "Should we expect the police?"

Sherlock shrugged and winced. "Probably. You know how Sgt Donovan gets when bodies are left lying around."

John raised an eyebrow at the mention of bodies, plural, but didn't otherwise comment as he picked up a forceps and a needle holder and began to close the wound.

Sherlock glanced down at the growing row of tidy sutures. "You do neat work."

John could feel his expression darken as he thought back to the Afghan desert. "I've had plenty of practice." He closed a few more centimetres of lacerated skin and then asked, "Are you going to tell me what happened?"

"Are you going to blog about it?"

John knew how touchy Sherlock could be about cases where he failed, or at least didn't succeed completely. He had said the police might come sniffing around, and not because they were seeking his help with an investigation. He shook his head. "Not if you don't want me to."

He would still document the case. But it would go on in a secure file meant for his eyes, and possibly those of Mycroft, if the situation warranted it. Sherlock knew about that file, given his habit of routinely hacking John's computer there was no way he couldn't, but he tolerated it.

Seconds ticked by. John continued his work, the needle biting into the desensitised skin. Finally Sherlock huffed a sigh, caving into the need to reconstruct the event.

"It was meant to look like a garden variety mugging. Man in the wrong place at the wrong time comes up against a bunch of lager louts looking for an easy target and some quick cash."

Once he had the tools in his hands, it was as if he'd never set them down. John worked on autopilot as he listened to Sherlock describe the set up of the ambush, methodically closing the wound with a curved cutting needle and length of sterile silk thread. "How do you know it wasn't?"

Sherlock shot him sour look that made John feel quite dense. He waved the feeling away. His friend had been injured, and despite the outcome of the fight, that was a blow to his pride. "Common yobs are seldom trained in Krav Maga. Someone was testing me."

"So who were they then? Moriarty's men?"

Sherlock gave a small shake of his head as if he'd considered the idea and immediately abandoned it. "Moriarty is a thorn in my side, John, but let's not make him into the boogie man. I have other enemies. Are you finished yet?"

John tied off the final suture and admired his handiwork. If Sherlock were careful and there were no complications, the scarring should be negligible. "Nearly. Hold still another minute." He injected Sherlock one final time and then dressed the wound, fixing a piece of gauze in place with surgical tape and then wrapped a more secure dressing over the top. "I'll pick you up some tablets tomorrow. Make sure you take them all." He went to the stove, poured a cup of warm cocoa and handed it off. "Doctor's orders."

Sherlock gave the cup a sceptical sniff. "Cocoa. Really?"

"Drink it."

John fixed Sherlock with what he hoped was a steely expression until he gave an exaggerated sigh and then lifted the cup to his lips. Dutifully, Sherlock drained the cup and then handed it back. "Happy?"

"Ecstatic," John replied. He glanced over at the bag of discarded clothes. "I'll go clean up. Burn your clothes in case the police do come calling." He began to gather his instruments, wrapping them in a green surgical towel to clean later. The discarded pieces of gauze and drape he swept away into a waste paper bin.

"I have work to do." Sherlock tried to get up from the table. He staggered and fell back into the chair, staring at John in disbelief. "You drugged me."

John shrugged. There were times that turn about was fair play, but in this case, it was in Sherlock's best interest. "Little bit. Yeah. Diazepam to help you rest. Come on. Let's get you to bed."

Carefully, he put his arm around Sherlock's uninjured shoulder and helped him into the other room. He'd already pulled back the blankets, so it was just a matter of getting his patient situated and tucked in. When he'd finished, Sherlock was still trying to shoot him a disapproving look, but the tranquillizer had taken hold and the frown that marred his mouth faded as he settled into sleep.

John watched the rise and fall of Sherlock's chest for nearly a minute, assuring himself that all was well before shutting the door. He glanced at the garbage bag and waste basket, dumped the basket into the bag and then went to his room. There, he checked and made sure his pistol was loaded and shoved it into his jacket pocket. With a word of warning first to Mrs Hudson to be wary of strangers, John checked the street door was locked and then went down to the basement.

He was sure the modification to the retrofitted boiler was Sherlock's doing. It made sense given the need to discreetly dispose of no longer needed body parts or other paraphernalia from his highly unusual research. John donned a fresh pair of gloves and fed medical waste into the special chamber and followed it with Sherlock's trousers and socks. He hesitated over the shirt, considering its value.

Blood meant DNA evidence. It was possible the DNA could be matched to someone on the police database and then they would have a lead not only to Sherlock's assailants, but possibly, if they were mercenaries, to their paymaster. On the other hand the shirt could implicate Sherlock in either a serious wounding or a murder. Even if it had happened in self defence, there were those in the police services who were slavering for an opportunity to discredit the man they saw as a meddlesome outsider.

John shoved the shirt into the boiler and shut the heavy door after it. Attackers' skills not withstanding, it was possible they were both making a mountain out of a mole hill. But as he checked over the flat and then looked out the window onto the quiet street below, he couldn't quite shake the feeling that something was brewing.

Intent on remaining alert, John made a pot of strong coffee. He paced the kitchen until the carafe filled and then poured himself a cup. Just as he was carrying it across the living room his phone rang, shattering the silence. Coffee sloshed over the sides of his mug as John abruptly set it down on the table. He took a deep breath and then let it out again before answering. "Harry. This is unexpected."

John glanced out the window again. The street was still deserted. He settled the phone more comfortably against his ear as his sister asked how he was keeping. "I'm fine. Just having a quiet night in. You?"

John listened to his sister ramble on about mundane things. He looked around the room, weighing his options if the flat were attacked. He'd shut the door and turned the seldom used key on his return from the boiler. There was, he decided, no better place to be than where he was, obscured by the wing of the armchair in the shadows of a half lit room. He made agreeable noises into the phone as he drank his coffee, and when Harriet finally wound down, he promised to ring her soon.

With a long empty night ahead of him, John settled as best he could with a fresh cup of coffee and his laptop. He updated Sherlock's medical file and then once he had finished, he began to document the facts of the case. It was a curious sort of domesticity, but he decided he wouldn't want it any other way.