John had found Sherlock staring at the mirror shortly after three in the morning, having drifted awake enough to realize there was an empty space in Sherlock's bed. He'd almost gone back to sleep, because this wasn't abnormal, but he'd remembered then that Sherlock was supposed to be sleeping off the effects of two days of not properly caring for his recently concussed self and John was supposed to be watching him.

The lack of sound in the flat had startled John into getting up quickly, ignoring the dizzy, groggy feeling that came with rising with too little sleep. He hurried into the living room to find Sherlock there, staring at the mirror, a stunned expression on his face.

But when his grey eyes slid to meet John's brown ones, John felt cold in a way that had nothing to do with the early hour or the lack of sleep.

Sherlock's eyes were gleaming.

John looked away then, at the mirror, and saw the message Sherlock had translated, scrawled across the glass.

"Is anyone listening?"

It made goose bumps jump up on his arms and the hair on the back of his neck stand up.

Sherlock was looking at him then, in the silence, that triumphant expression still in his eyes, and John wondered how long it had been since he'd decoded the message, how long he'd been contemplating it.

Then he wondered how bloody fast they could catch this killer and get him off the streets before Sherlock started enjoying the fact that he had another dangerous adversary.

Probably too late for that.

But now there was noise, the babble of voices in Lestrade's office, the volume too high for the small space, threatening to break out of the constraints. John had no idea why there were so many people in the office – they seemed to have attached themselves to the case somehow, fulfilling functions he didn't understand, but, by the looks of it, Lestrade didn't necessarily understand, either. The DI looked harassed – a normal expression he wore when Sherlock was around – and tired and more than a little aggravated. Donovan was there, which made sense, but also Anderson, which didn't, and other people John didn't know, officers and detectives, all of them who seemed to be talking at cross-purposes, above one another.

In the midst of this, Sherlock sat facing Lestrade's desk, in a tiny patch of silence that he cultivated for himself. He was in his black coat and purple scarf, sitting with his legs crossed, shoes immaculately polished as always, watching the DI with a level, removed expression.

Gone was the triumph John had seen earlier, that dangerous glimmer in his eyes, that expression of appreciation that made John worry, because he'd seen Sherlock sport it when dealing with Moriarty.

To Sherlock, this was not just interesting. It was fascinating.

And fun.

But now, John thought, now, no, he doesn't look like that. He looked impatient and mildly annoyed at the babble around him.

"How is it that the lunatics always find you?" Anderson demanded and John repressed a sigh – he hadn't been hoping that a run in could be avoided, because he was more of a realist than that. He just wondered what the fascination was with the constant antagonism. It was as though it was a source of energy for both men, like sunlight for solar cells. As though, if they went too long without it, they'd power down and cease functioning on some level.

Sherlock shifted his cool grey eyes from Lestrade to Anderson, narrowing them somewhat. He delayed answering, which irked the forensics officer, and John saw Donovan cross his arms and scowl. Probably at both of them, John thought.

"Tell me something," Sherlock inquired smoothly, his voice as cool as his eyes, which John classified as definitely 'Not Good.'

"What?" Anderson snarled.

"Do you have to write yourself detailed notes daily to remind yourself to breathe? Is this why your brain cannot function on higher levels?"

Anderson stared at him and John was certain, absolutely certain, that Donovan repressed a snort of laughter hard, visible only as a small shift in stance and a quick glance away, then back.

"The message said 'is anyone listening?'" Sherlock continued before Anderson could retort. "Not 'are you listening?' It was clearly not meant for me specifically, but for whoever could interpret it. Which so happens to be me."

"So you think like a madman," Anderson growled.

"Our killer thinks like a madman, a psychopath," Sherlock corrected, cocking an eyebrow, but his expression was not entirely condescending, there was anger in there as well. "I think like a genius. Although I appreciate that this distinction is lost to you."

Anderson curled his lip but Lestrade jumped in.

"Shut up, the pair of you," he said. "And everyone else, just shut up. This isn't getting us anywhere. We still don't know who he is or where he's picking up his victims. We barely know what he wants, except for someone to listen to him."

The rest of the voices stilled at the DI's insistence, but Sherlock and Anderson continued to glare at each other. Donovan exchanged a look with John that was laced with years of experience dealing with both of them, although John suspected now he'd had his fill of Anderson. He was keeping himself away from the forensics officer, and hadn't even called Sherlock "freak", which, admittedly, he didn't do around John anymore, because he'd given him a black eye and split lip the first time he'd heard him say it. He seemed weary and tired, and not in a way that had much to do with lack of sleeping or being roused very early in the morning.

"Well, we know the question, let's give him an answer," Anderson snapped.

Sherlock's expression shuttered and his eyes flared and John repressed a groan.

"And then what?" he demanded in an icy voice before Lestrade could intervene again. "Shall we say yes and have him reply? What would he say in return? 'Oh, lovely, such a pleasure to meet you'? Which would require eight more pairs of murders on his part, I might add. Anything we say to him could be met by a response in his very particular way. Is that what you want?" At this, Sherlock glanced about the whole room, meeting other eyes pointedly.

John was somewhat surprised, although he disliked having to admit that. Sherlock was actually considering the possibility of more victims above possibility of continuing the game?

But that wasn't entirely fair, was it? He'd gone after that cabbie the very first case he'd worked with John, to prevent the man from hurting Sherlock and anyone else.

Then, John realized, the game had already been played, the puzzle solved. Any more messages after this, Sherlock would be able to decipher easily, unless the killer changed the pattern, which John thought was unlikely.

The game now would be finding him while avoiding any more murders.

"Or perhaps you think if we let him know someone is listening, he'll simply turn himself in?" Sherlock inquired.

Wouldn't that be brilliant? John thought. It would be nice if they could announce that they'd received the message, and yes, they were listening, and the man would simply show up at the Yard and surrender.

Without leaving another trail of bodies behind him.

Not bloody likely, John mused. He wondered how many more victims there were beyond these ten, how far back it stretched. He suppressed a shudder; what went wrong in the formation of a person's brain to make them like this? What bit of human empathy was shut off or left out altogether that created someone who could simply shoot a stranger in the head and walk away?

It made the doctor in him enraged and the rest of him just cold.

"Wouldn't be much fun for you, would it?" Anderson snapped and John bit down on a groan; he chose now to become perceptive and start accurately judging Sherlock's reactions?

"Shut up," Lestrade snapped again, shooting an angry look at his forensics officer. "Bickering isn't going to get us anywhere. I'm not making any decisions on this without orders from above. And we haven't even worked out what his pattern is. We still need to pin that down. He's a bloody serial killer. He wants us to know who he is."

John expected Sherlock to object to this, but he didn't, and Lestrade was only echoing the words Sherlock had spoken to John about serial killers on their first case anyway.

Lestrade sighed abruptly and waved a hand.

"Right. Everyone out. Donovan, Sherlock, John, you stay. Everyone else, piss off."

There was hesitation and Lestrade smacked an open-palmed hand on his desk, giving a glare round the small room for good measure.

"Well? Are you waiting for an engraved invitation? Go!"

With a degree of unhappy muttering and not a few dark looks cast at Sherlock, who ignored them with usual stony silence, the rest of the officers filtered out. Lestrade waited until they left, then waved a hand at Donovan, who shut all of the blinds on the windows quickly, moving with an efficiency that suggested he was well used to it.

Lestrade pressed his fists together and dropped his head against them, staying still for a moment, then looking up. John felt a stab of sympathy for the DI; it was far too early in the morning for this and he looked as though he hadn't got much sleep as it was. Donovan took a chair recently vacated by another officer, exchanging a look with Lestrade.

"Why is he doing this?" the DI asked, not really addressing Sherlock, John thought, but the world in general.

"To see if someone is listening," Sherlock replied shortly.

"Yes," Lestrade said, rolling his eyes. "I rather got that from his ridiculously convoluted way of sending a message. But why is he so invested in finding out if we're listening to him? He's bloody left a trail of bodies from Sheffield to London. Of course we're listening to him."

"He doesn't have to have a reason," Sherlock pointed out. "He's a psychopath. He's likely doing it to see if he can."

"Not at all reassuring," Lestrade sighed. "Any luck finding anything similar, Donovan?"

"No," Donovan said. "I've been checking on murders involving the victims being tied up in some way going back the last ten years and there's nothing that fits our man's pattern."

"This is the first time he's used this pattern," Sherlock snapped.

"I know," he replied coolly. "But we were hoping for something that might tip us off. He had to start somewhere."

Privately, John agreed with that. Lestrade drummed his fingers on his desk, then against his lips, and Sherlock followed the movement with his eyes and it was with some shock that John realized that both other men were probably itching for a cigarette.

"Sherlock. Do you think he's a genius?"

"Just come out and say it, Lestrade. Do I think this is another Moriarty?"

John held back on a curse and saw Donovan stiffen but Lestrade only narrowed his eyes.

"We're dealing with a man who came up with the idea to use scarves binding his victims to send a coded message in shades of blue, Sherlock. This isn't normal."

"I'm not saying he isn't as smart. I'm saying he's not as connected. What kind of person sends the message 'are you listening?' the way he did? When Moriarty wanted to know if people were paying attention, he strapped bombs to his victims and actually spoke with us through them. If he really wanted to know that we were paying attention, he could have blown up half the city without much trouble. He was well connected, Lestrade, likely more so than we'll ever realize. This person, whoever he is, is working on his own. He's moving across England by himself, I've no idea why, so don't ask."

Lestrade stared at him.

"So, what, we have a lonely psychopath on our hands?"

"Yes," Sherlock said simply.

"Brilliant," the DI muttered.

"It may be why he's killing couples," Sherlock pointed out and John recalled suddenly the conversation they'd had in the pub, when Sherlock had noted the killer was targeting couples. "It may be that he's idealizing them somehow, and killing them negates what they have and he does not."

"You think so?" Donovan asked and Sherlock glanced over at him.

"I don't know," he said in what was, for him, a conciliatory tone of voice. "Until we determine why he's choosing the victims he's choosing and where he's finding them, I can do little more than speculate."

"Comes back to that," Lestrade sighed. "Keep working on it. I'll get Sam to check up for similar cases in the rest of the EU in the morning – later in the morning, I mean. Donovan, keep looking for anything that may even remotely look similar to this in the Sheffield-London corridor. Damn. Sherlock, as much as I appreciate you figuring this out, couldn't you have done it a bit later in the day?"

"Really, Lestrade, you're a DI. Lack of sleep comes with the territory."

"Oh, it's not that," Lestrade said wryly and John saw a similar type of smile tug at Donovan's lips. "It's the shit I'm going to get from calling up the brass at this time of day– night. Get back to work, Sherlock, and John, make sure he doesn't bloody kill himself by overworking with a concussion."

Sherlock huffed and John bit down on a smile at seeing the Consulting Detective casually reprimanded like a disobedient child by the DI, who didn't even seem to realize he'd done it.

"Will do," John promised and saw Sherlock's expression darken again, which made him unable to keep the smile off of his lips this time.

"Come on, John," Sherlock said coldly, mustering the haughty air he assumed so well, which John knew was not at all feigned. "Apparently, I require adult supervision."

John saw Donovan grin and flashed a smile back, pushing himself out of his chair. He bid good morning to Lestrade, not at all envying the other man's position, because he was going to have a load of angry superior officers to contend with quite soon. He followed Sherlock out of the door, keeping up with practiced ease as the Consulting Detective breezed coolly through the station and back out into the chill morning air.

Sherlock was uncharacteristically silent on the cab ride home, glaring out the window, and John wondered what it was – couldn't just be Anderson and his momentary insight into Sherlock's mind, although that was probably part of it. If it had only been that, however, Sherlock would have happily railed about it, finding any number of other examples to prove how the other man was really a dullard, highlighting the most interesting ones for John, even if John knew them.

Sherlock's eyes flickered to street signs and alleyways as the passed by them, and John wondered if he were tracing routes on foot for them. Maybe they should have walked? It usually took about forty-five minutes to do so, even with Sherlock's "short-cuts" – privately, John did not consider zigzagging through a maze of alleys to be a real short-cut – and this was a tolerable amount of time when it was not a freezing early November morning.

All things considered, he was glad they were warm in the cab.

John paid the driver when they arrived at the flat, because Sherlock just got out and strode toward the front door without bothering to check for pedestrians or traffic – not that these were a big concern at this time of morning. Although a bloke on a bike with a flashing headlight swerved around John when he stepped out, startling the doctor somewhat. John shook his head and hurried after Sherlock who had, at least, not just let the door shut behind him, so John could step into the welcoming warmth without having to fumble for his keys.

Once inside their flat itself, John opened his mouth to ask what was bothering Sherlock, but the detective forestalled him by walking over to the phone and ringing a number. John was tempted to snatch it from him.

"Lestrade? No, I have not solved the case in the fifteen minutes since I saw you. I've only just got home. Shut up a moment. I want to press charges against the man who threw the beer mug at me. Yes, I know I said I didn't before. Now I do. Can you add accessory-after-the-fact to those charges? You did say you could be creative– what? Because if it bloody well weren't for him, I wouldn't have a concussion and I'd have been able to stop the murderer before the final victims! Or at least be able to trace his blasted patterns! Yes, of course I'm serious! What do you mean, no judge would accept that? The man is keeping me from doing my job properly! No, of course I don't mean the murderer, try to keep up, will you? What? What! Bloody typical, isn't it?" He paused for a sigh, shaking his head. "Well, yes, I'm still serious. Fine, if you can't add that, but what can you do, other than assault? Yes? Yes, yes. That sounds fine. Good. Thank you."

He rung off without saying good-bye, then turned to see John staring at him.

"What?" he asked.

"Sorry," John managed. "Just unexpected, is all."

Sherlock shot John a glare.

"My head bloody well hurts, John," he said. "And itches like mad. And I can't concentrate. How am I to be expected to do my job like this?"

"Um, you deciphered his message," John pointed out. "Which no one else even picked up on as a message."

"And how long did this take me?" Sherlock snapped. "Meanwhile, he's roaming about, probably selecting more victims for his next ridiculous message while we try and scramble to keep up after him because some complete lack-wit couldn't calculate angles and trajectories properly and hit me instead of his intended target."

With a huff, he threw himself into his chair. John repressed a smile, knowing it would be entirely misinterpreted; he wasn't smiling at Sherlock's injury, but Sherlock's attitude. It probably wouldn't do to say so, but this sort of petulance probably meant he was feeling more himself. John had been surprised when Sherlock had initially refused to press any charges.

Sherlock propped his feet on the coffee table and John ignored the fact that the soles were wet from a recent rain, and glared at John, still wrapped in his coat with its upturned collar and his purple scarf and leather gloves. He looked tired around the eyes, despite what were probably his best efforts to hide this.

"You know, there's a good body of medical research on the benefits of regular sleep and regular meals," John said.

"Oh, please," Sherlock snorted, pressing a gloved fist against his lips momentarily. "Do feel free to lecture me more. I already know that. Living with a doctor allows something to rub off, you know."

Yeah, the knowledge, not the habits, John thought, his lips quirking. Sherlock gave him another glare for a good measure and John shrugged off his coat, unwinding the scarf from around his neck. It was the fourth one Sherlock had bought him, even though the other three were still in great shape.

He hung up his scarf and coat and turned back to Sherlock

"Sherlock, you had– have, actually, a nasty concussion. Sure, it's getting better, but you're not helping by refusing to eat and sleep properly. It seems to me you need three things: a good, hot meal followed by a good long sleep."

Sherlock arched his eyebrows at him.

"That's two things, John," he said. "I know you've mastered basic counting. I'd hope they wouldn't let you become a doctor without that specialized skill. What's the third thing?"

Sherlock's eyebrows twitched farther up in realization.

"I don't need the distraction, John," Sherlock replied. "You can take care of yourself, I'm sure."

"And what would you rather do?" John asked, gesturing with an open palm to the paper-disaster area that was their flat, files littering all the surfaces, the dratted scarves still on the table, the map pinned to the wall, the mirror with the killer's grim but almost self-indulgent message scrawled across the glass. "Sit out here uselessly, stewing about how you can't work and thinking about Anderson? Or come into the bedroom and have a good think about me for awhile?"

Sherlock stared and John grinned, knowing he'd hit his mark.

"How did–" Sherlock started, then clamped his lips together, refusing to ask John how he'd known Anderson's remark was eating at the detective. It annoyed Sherlock, he knew, that John had become so good at reading him. Not as good as John would like to pretend, though.

Sherlock stared at him a moment longer then his lips twitched and he passed a hand over his eyes, and John considered that he'd won.

"I have not had any nausea in seven days, John."

"But you have had dizzy spells. Which can lead to nausea. Which can lead to vomiting."

"And how do you ensure this won't happen now?"

"I'm a doctor," John sniffed. "I can tell." He didn't bother including that he was just feeling impatient by now and wanted to get his way, which did not at all involve taking care of himself, as Sherlock put it, nor listening to the complete lack of patience Sherlock would develop for his work if he went on like this.

"It will completely ruin the order of importance you listed to me a moment ago. A hot meal then a good sleep?"

Sherlock peeled off his gloves, tossing them on the coffee table, and stood, reaching to undo his scarf.

John woke him up an hour later with two painkillers and a glass of water.

"Take these," he ordered in his Doctor Watson voice that brooked no arguments, but Sherlock seriously considered trying anyway, just to keep his hand in. It wouldn't do to have John assuming Sherlock would listen him just because he happened to be right once in awhile.

That sort of encouragement could be habit forming for John. Then there would be no end to his stubbornness.

He passed off a glass of water and Sherlock downed the pills without comment, then consented to get out of bed. John fetched himself a beer, but apparently this was not on the menu for Sherlock, who wrinkled his nose at John when he came back into the living room.

He put Sherlock on a strict schedule of meals, sleep, and what he called an "exercise regime", and Sherlock vaguely regretted that John's memory extended to what he, Sherlock, considered unnecessary information.

Between these chores – the last one not really being a chore, but best not let John start to suspect that Sherlock was not entirely put off – Sherlock was allowed (allowed!) to work as much as he pleased, although John put out four glasses of water on the kitchen counter every morning and expected them to be gone by the time he got home.

Sherlock drank two and retaliated by pouring the contents of the other two down the drain. He had considered watering their plants, but John would probably notice he'd done this.

He was thirty, for pity's sake. Not three.

Somehow, he could not bring himself to feel as indignant about all of this as he wished, particularly when John had left for work Wednesday morning – having called out Tuesday due to the chaos resulting from Sherlock's deciphering the message and then, of course, what had happened once they got home.
 

A day and a half later, Sherlock still had made no progress on determining how and where the killer was selecting his victims.

It was absolutely maddening. There seemed to be no pattern, save for a general southward trend that ended in two pairs of murders in London and the fact that all of the couples were married.

Age, religion, ethnicity, income, it seemed to make no difference. Their fields of work didn't overlap, neither did their social circles, even the two in London. They weren't even all British; Rebecca Garrett had moved to England from Ireland after meeting her husband several years previous, and Sara Clayworth had been born and raised in New Zealand for the first eight years of her life. Sherlock checked to see if the others had lived abroad, and one or two of them had, for short periods, but the others hadn't, so there was no pattern there, either.

Had he just picked names out of an phone directory?

Punched in random numbers until he got someone?

Or perhaps he had pulled them out of a hat?

Regular updates from Lestrade were regular updates about nothing, and Sherlock tried in vain not to think about the fact that the three cases previous to the London cases had gone cold.

Shortly after lunch – which Mrs. Hudson ensured he ate and Sherlock was certain John was paying a bit more on their rent for this service – Sherlock got out his violin and tried to play, but it didn't help.

With a growl, he replaced the instrument and felt the silence in the flat pressing in on him. He closed the violin case and clicked the latches back shut and thought of the cellist he'd seen at Angelo's the previous week. Had it only been just over a week ago? He glanced about the flat, at the mirror he hadn't let John move yet, at the scarves still spread out on the table, at the map of England pinned to the wall, more of his handwriting scrawled all over it.

He needed music yes, he thought, but not his own.

Sherlock fetched his coat, scarf and gloves and left the flat.

He knocked on a back door and waited a few minutes, bundling his hands in their gloves into his pockets, huffing frozen puffs of air. Sherlock glanced around; no one cared about this particular door, since it was only used by a handful of staff on their cigarette breaks and was tucked out of the way. One of those regrettable little messy and industrial spaces every large building had.

The door eased open and Sherlock stepped inside.

"Hello, Roger. Finally quit then, have you?"

"Now, Sherlock, how could you possible tell?" the security guard said with a twitch of his lips.

"Your shoes," Sherlock said.

"My shoes, eh, young man? And what's so special about my shoes?"

"They're dry, still polished, not a speck of dirt or mud on the leather, nor around the edges of the soles, so you've been staying inside. Avoiding the outdoors for your breaks, which means you haven't been standing in the rain for the past few days. Of course, you could have cleaned your shoes before coming in today, but if you'd gone outside at all today, you'd have tracked some remnant rain or mud onto your shoes. No ash, either, I note, so no absently flicking your cigarette. Also, your breath smells like mint, so you've been chewing gum or sucking those horrible breath mints we all rely on at the beginning – have you tried patches?"

Roger pulled his shirt sleeve up and beamed in approval at Sherlock's deduction. But really, it had been elementary, and the man's wife had been after him for ages to stop.

"Finally given into the missus, have you?"

"My doctor, actually," Roger replied. "Never too old to stop, he says."

"As does mine," Sherlock replied with a smile, although he had never actually smoked since meeting John. "And he's quite right. You want to enjoy your upcoming retirement, don't you?"

"That I do," Roger sighed. "Would prefer to enjoy it with a good smoke, but maybe a cigar."

"Stick with champagne, take it from me. But not too much."

"You're the expert," the older man agreed with a wink.

"In quitting, I believe we are all amateurs fumbling in the dark, hoping to get it right," Sherlock admitted. "However, sometimes, it actually works. May I go in?"

"Please do," Roger said, gesturing down the service hall.

"Who's in today?"

"The London Orchestra is still working, I believe. A few films, too, but don't think they'd be your style."

"London Symphony Orchestra," Sherlock corrected.

Roger just twitched his grey eyebrows at the younger man and Sherlock gave him a smirk in return as they made their way down the hall. He let Sherlock into a service stairwell and the detective thanked him, waiting until the door had closed again, shutting the late-fifties, salt-and-peppered haired security guard from view before taking the stairs two at a time. This was more sedate than his typical three at a time, and he thought John would be quite pleased, had he known.

He let himself easily and expertly into the vast and empty symphony hall, where, indeed, the London Symphony Orchestra was in full swing during rehearsal. Sherlock came into the very back of the balcony, stage left, and settled into a seat in the darkness. The entire auditorium was dark, of course, except for emergency lights on the floors along the aisles, since the orchestra was in rehearsal only and ostensibly closed to the public.

Sherlock slouched down – John hated when he did this, said it was bad for his back, but it was his back, so he should know – and closed his eyes, folding his hands over his stomach, propping his right foot against the seat in front of him. If this had been a performance, he mused, this would probably be a hanging offense.

He listened to the sounds as they drifted up to him – apparently, they were practicing the overture from the Marriage of Figaro. He smiled, because this was one of his favorites and John didn't care for it, for some unknown reason. Had he partnered with the most unreasonable man in history? No, certainly that would be Mycroft. This thought made him smile more and he opened his eyes when the music ceased and the conductor shouted something passionate at the bassoonists.

It lasted less than a minute and then there was the shifting of instruments and the orchestra paused as the conductor lifted his hands, holding them off a moment, and Sherlock closed his eyes when the music resumed.

He didn't do this nearly enough, he considered. It was enjoyable, free, and, best of all, it avoided the unnecessary and tiresome social interactions that clouded attending an actual performance. In this, it was just him, and the music.

A door behind him and to the left opened and shut nearly soundlessly and he scowled, slumping further down in his chair.

Damn, he thought. Was he caught? If it wasn't Roger, but another security guard, he may have to dash. Although he still had Lestrade's police badge from the previous week, even if John didn't know this, and the DI had probably realized Sherlock had nicked it and just replaced it without reporting it stolen. It would be another drugs bust soon for him, he was certain.

The creak of a chair taking someone's weight made him open one eye and look over. A male figure had seated himself in the row behind Sherlock, near the other end, and did not seem to notice that he was there. The detective stayed still, keeping his ears tuned to the music but trying to evaluate his unwanted companion.

A man, certainly, because the silhouette gave that away, and probably younger than Sherlock, but at least in his late twenties, and tall, though not as tall as Sherlock himself. He held himself too well to be much younger, particularly an adolescent, but any more was difficult to ascertain, because it was too dark.

As though he sensed eyes on him, the stranger turned his head, making small motions as if trying to see Sherlock, to make out the distinction in the shadows. Sherlock stayed utterly still, hoping this would dissuade him, because he really did not want company and he felt mildly annoyed that someone had intruded on the habit he'd taken as solely his.

A moment later, the other man raised a hand, waving once, in acknowledgement if not greeting. With a sigh, Sherlock mirrored the gesture, then returned his attention to the orchestra below, letting the music wash over him.

He was hoping to be let alone, but after a few minutes, the chair creaked again and Sherlock scowled as he heard light footsteps approaching him, then weight against his row as the other man leant on the back of a chair two seats down from him. He tilted his head back, adopting a bored expression, but was surprised – shocked, really – to recognize the younger man peering through the darkness at him.

In the faintest of lights, his brown eyes seemed even darker, almost completely absorbed by dilated pupils that were attempting to pick up whatever illumination they could. His face split into a grin of recognition after a moment and Sherlock repressed a sigh at the banality and insanity of running into a stranger he'd actually met before, while enjoying an illicit symphony performance.

"The violinist," the younger man said, his voice low, smooth. It had a lovely cadence, Sherlock noted, and he wondered if the younger man was also a trained singer. But he was also a smoker; Sherlock could smell the distinct odor of strong cigarettes on his clothing and likely his hands. Given the concentration of the smell, he had had at least one before coming inside. Sherlock hadn't noted the smell on him at Angelo's, but neither had he been as close, and the younger man may easily not have had any cigarettes immediately before that. He sniffed quietly; the scent was familiar, not the brand he'd preferred, but he was certain he knew it, although could not place it.

"The cellist," Sherlock replied.

"Fancy meeting you here."

Sherlock gave a small grunt and silence fell over them again as they returned their attention to the music for several minutes, but something niggled at Sherlock.

"How did you get in?" he inquired, keeping his voice quiet. Surely he was Roger's only source of additional income in this regard, because he paid quite dearly for that service. If any of the other security guards had a similar arrangement with this cellist, he was going to have to make his business to find out about it.

"There are ways, with the right tools," the cellist said cryptically, flashing him a smile. "You?"

Sherlock didn't deign to reply, refocusing on the music.

"Why come now?" the cellist asked after a minute.

"I prefer my symphonies without the crowds," Sherlock said.

"Ah, the man with no audience is an audience of one of for our very own LSO. Somehow poetically apt."

Apt, Sherlock thought. Well educated, even though his accent was middle-class, suggesting he was adopting it to better blend in or he'd been sent to a decent school above his parents' means on a scholarship or some such thing. Sherlock strongly suspected the latter, because there would be no need to blend in here, with only one other person for company and Sherlock's educated and upper class inflections. Unless the other man could not tell that, of course, because educated did not mean observant or intelligent.

"Quite," Sherlock replied. "And you?"

The other man shrugged; Sherlock caught it out of the corner of his eye as a shifting in the shadows only. After another moment, the man stood and easily stepped over the backs of the seats to settle in the same aisle as Sherlock.

"A goal, perhaps?" Sherlock asked, nodding to the stage, where the conductor was now haranguing one of the violinists. They waited until the music had sprung up again, from the beginning of the overture.

"One day, it would be nice, maybe," the younger man agreed. "A professional's fondest dream. But I have a steady job that I like."

"And yet you come here," Sherlock observed.

"And so do you."

"Yes, I did explain that," Sherlock replied with a slip of impatience in his voice. The other man grinned at him, his expression seemed starkly shadowed in the dim light, his face all angles and darkness, which created a disconcerting effect not unlike someone shining a torch on their own face from below. But with less illumination.

"To give them an audience," he replied easily, sitting back, hands on his knees. "Like I said, we all play for one. And they're down there," he nodded at the stage, "Rehearsing for an empty auditorium. Bit dull, don't you think?"

Sherlock was inclined to shake his head in disagreement; he would prefer playing for the empty auditorium, for the silence that ate up the notes and only wanted more, rather than the tedious audience with its shifting and shuffling and yawning and sneezing.

But his audience was John and Josephine. He wanted nothing more. Had he done so, he may have pursued the same goal that lead the musicians below to where they were on the stage.

"Is anyone listening?" he said softly, without intending to.

"Yes, I sup–" the younger man started, then froze.

Sherlock froze in response.

No, he thought, then realized that yes, it was.

They turned to stare at one another and Sherlock was up first, but the younger man had anticipated this and shifted backwards, dodging his head out of Sherlock's way and then ducking forward again, pushing himself to his feet fast. Sherlock grabbed him, pushing backwards, trying to off-balance him but the younger man shifted his weight to one leg and kicked out, catching Sherlock in the knee. The detective hissed, battling for stability, tightening the grip he had on the other man's arms and pulling the cellist toward him.

They were both hindered by the narrow width of the aisle and the seats surrounding them, but Sherlock had experience and he launched his weight forward as the younger man lost his balance from being drawn toward Sherlock. The detective forced him back, pressing him against the seats and the younger man grunted, the arms and seat back digging into his own back. Sherlock pushed him into the seat hard, forcing his spine to bend uncomfortably and heard a hiss, and caught the younger man's head as he tried to snap it forward into Sherlock's mouth and nose.

"Don't think so," Sherlock panted and the younger man elbowed him hard, in the side, bringing his right arm around with considerable force. Sherlock grunted, releasing his hold somewhat, and the younger man took the advantage, dislodging himself and the detective, grabbing Sherlock's lapels and forcing him down onto the seats, almost reversing their positions.

Sherlock drove his own elbow into the younger man's left forearm when he went to close his hands around the detective's throat, ducking and moving forward, wrapping his hands around the younger man's waist, vaguely shocked no one below had seen or heard them, but then, how? It was dark, and the orchestra was in full swing.

They grappled, trying to find purchase as much as they tried to best the other, both of them breathing hard, the younger man cursing once.

"Police!" Sherlock hissed, knowing it wouldn't work, because what criminal madman simply surrendered when the police identified themselves? Sherlock certainly never did.

He managed to gain enough space, keeping himself low, ignoring the younger man grasping at his coat and trying to off-balance him yet again, to swing a punch at the attacker's stomach, causing him to double over. Sherlock ducked out, catching him as he did so, but the younger man fought this, drawing on reserves of strength Sherlock told himself he should have noted – if he'd noted the man was a raging psychopath.

Now wired on adrenaline.

He kicked at the younger man's ankles, swiping, to get him off of his feet. The younger man stumbled but threw his weight toward Sherlock instead of just letting it go undirected and the detective grunted, grabbing his shoulders, pushing his arms back to prevent being at the end of a swing himself, but the younger man turned into this, shoving himself forward, shoving Sherlock backward so that they fell against the seats again.

The younger man swung and Sherlock ducked with another grunt, gritting his teeth, pushing himself into his attacker for space and to get him to lose his balance in the narrow aisle. The younger man cursed again and Sherlock threw a punch of his own, missing his mark, hitting him in the chest. The man huffed, stumbling back, winded, and Sherlock managed to stand, silently cursing the tiny space, swinging again, this time with better aim, catching the younger man square in the jaw, sending him toward the seats.

His attacker swung out an arm as he fell, connecting with Sherlock's head in an open palm that turned into a fist immediately when it came into contact with something and Sherlock felt his head being instinctively jerked backwards.

No, he thought, nausea and dizziness gripping him instantly. He made an involuntary sound but forced himself to ignore it, grit his teeth against it, drag his head back up.

The younger man hissed, triumphantly, and jerked Sherlock's head back again, yanking hard on his hair. Sherlock kicked again, calculating where the younger man's shin would be, and connected hard with his heel, just below the knee. The younger man hissed again, no triumph this time, and released his grip and Sherlock regrouped, pressing a hand against an arm rest, ready to push himself up when a hand closed over his face and he felt his head being snapped back against the back of the seat.

The darkness swam and he lost his grip, fingers flexing convulsively to reclaim it. The younger man gave a startled laugh, then drove Sherlock's head into the arm rest, hard.

His breath was knocked out of him, his lungs contracting painfully, the stitched and healing wound on his head flaring in new pain that seared down his spine, through his brain. He gasped, but the sound seemed muddled somehow, distant.

"Oh," the younger man said, almost pensively, and smashed Sherlock's head against the arm rest again, hitting precisely the same spot.

His brain lost its control of his body and he was slipping against the folded seats, hands trying to grasp something, anything. He felt his head connect again and gave a grunt, or thought it, his lips moving, but there seemed to be no sound, no sound from him, but there were violins below, music enveloping him. There was a brief, breathless laugh and then whatever was holding him was gone.

A moment's hesitation, a quiet curse, and footsteps receding quickly, quietly. Sherlock tried to breathe, tried to remember how to breathe, tried to hold onto something, tried to force his legs to cooperate, to keep him up, to push him back up, tried to get his hands to grip but there was nothing there, nothing but air, and then the cold floor connecting with his body and an odd, hot agony radiating out from the crown of his head.

Then total silence and a welcomed darkness.

Lights.

"Hey, hey, can you hear me? What's your name? Wake up, wake up. Can you hear me? That's it, that's it. What's your name?"

"…John…"

"Good, John, good. How many fingers am I holding up?"

Lights.

In his eyes.

"Do you know where you are?"

No.

"His name isn't John, got his wallet."

"Listen to me, what's your name? Can you tell me your name?"

"John–"

"Who's John? Can you tell me who John is?"

Fingers curled over where John's hand should be. Curled over nothing.

John.

White.

Lights.

Sweet air.

Brown eyes.

"Can you hear me?"

More lights, in his eyes, he pulled away, pain flaring again, but so comforting, now, so normal.

"No, no, I need to check your pupils. Can you hear me? My name is Doctor Bates."

Fingers on his skin, latex. Something on his face, restrictive.

"You're all right, you're all right, hold still. Can you tell me your name?"

John.

"Your name, can you tell me your name? Can you tell me where you are?"

Home.

Violins.

Cellos.

"You're all right, we're going to take care of you. Can you hear me? Nod if you can hear me."

Whimpering. Muscles flared with pain, coursing down from his head. One nod. Too much.

"No, no, no, stay with me now. Stay with me. Focus on my voice. You can't sleep. I know you want to."

"…John…"

"What's that?"

"John…"

"John? Who's John? Can you tell me who John is?"

Everything.

"Sherlock?"

Footsteps, fabric moving, footsteps. Shifting shadows, shifting light. He moaned against the brightness, fingers twitching.

Something wrapped around them.

Something warm. Familiar.

John looked down at him.

"You bloody idiot," John murmured, voice was so loud and Sherlock winced, trying to turn away, but he was heavy, all over, and movement was pain and his eyelids dropped closed.

"Stay awake!" John said but it didn't matter.

Sound.

So loud.

He couldn't move.

Couldn't see, couldn't move.

But it didn't matter.

Drugged. He'd been drugged. Morphine? Yes. John had said– something. Morphine. Who cared?

The sound was familiar.

Cellos.

No, too loud. Resounding. He turned the word over in his mind. Re-sound-ing. Resonating. Sonar. Solar. Sun. Strum. Strings.

Cellos.

Remember. Cellos.

He tried. But he played violin. Certain about that.

Magnets?

Oh yes. Magnetic– something. He wanted to laugh. For no reason.

The sound went on, and on, and on, until it was the only thing, that and John.

John.

Then it stopped.

He stopped.

A phone call to Mycroft had Sherlock in emergency care almost before the police had arrived, dislodging the female detective John had never seen before and who was trying to ascertain what had happened, as if John knew. Sherlock had drifted in and out, struggling to hold onto consciousness, John could see, and had said all of two things: "John" and "cello".

Neither was very helpful.

And John wasn't certain at all about that last one, although Sherlock had inexplicably been at the Barbican when they'd found him, having apparently broken into one of the LSO's rehearsal sessions, so it might have made sense from the context alone.

He had ruled out "Jell-o" because he knew for sure that Sherlock didn't know what this was, especially since John himself kept it out of the flat. If his genius ever got hold of it, for experimental purposes, there'd be no end to the disasters.

The detective quizzed John, who knew nothing past what the paramedics had told the doctor. Yes, he'd called 999 and had them trace Sherlock's phone and stayed on the line, heart pounding, lightheaded, in a cold sweat, until they'd found him and told John, via the emergency operator, where they were taking him. He relayed this to the detective, who seemed stuck on why Sherlock was in the Barbican in the first place, and John had snapped finally, wishing, for once, that it was Donovan, who would at least listen to him. More or less.

The arrival of Lestrade and Dimmock, who came in together, and John wanted to groan at the presence of more police, even though he'd called the DI himself and fully expected him to haul out their Interpol connection. When Lestrade was uncertain, he liked to spread it around and make as many other people as uncertain as possible. John wondered if this pooled uncertainty could then be recombined into something that made sense.

"Where is he?" Lestrade demanded, casting a quick and expert glance around the tiny curtained room – Mycroft would get them relocated to a private room, but Sherlock still needed emergency care. "What the hell happened?"

"I don't know," John replied. He'd been repeating this at regular intervals to the detective and the doctor and wondered if anyone might start to believe him anytime soon.

He relayed what he did know – what was pieced together from a patchy phone conversation and information from the paramedics via the 999 operator: Sherlock appeared to have been attacked, and whoever had attacked him had either known or realized that he had a healing head injury and had hit his head repeatedly on the arm of one of the auditorium chairs before leaving him there.

For dead?

John shuddered.

"John. You should sit."

John blinked, remembering Dimmock was there, and noted the lack of agent-on-duty expression on his face. He was letting Lestrade sort things out with the detective, insofar as they could be, and John listened as she told him that the Barbican was being combed and the crime scene was secure. It was the first he'd heard about that.

Dimmock was wrinkling his nose, which John found odd.

John sat down, repressing an inward groan of relief. He hadn't realized how shaky his legs were. He rubbed his face with his hands, waiting for a moment to catch up, for everything to catch up with him, for things to start making sense. Lestrade and the detective had stepped outside, at least, so it was less crowded in the tiny room and the gurney was missing, too, since they'd taken Sherlock on it.

"Do you need something? Water? Coffee?" Dimmock asked.

Coffee. That sounded brilliant. Even the thought made John's mouth water, but before he could reply, the curtain was twitched aside and the orderlies were wheeling a sleeping – or unconscious, because he was drugged – Sherlock back in, followed by a doctor and a nurse and Lestrade and the detective.

Now it was crowded. It put John in the mind of a field operating theatre.

"Who are you people?" the doctor demanded.

Both police officers and the Interpol agent drew their badges and the doctor raised his eyebrows in surprise.

"It was my understanding that he was the victim," the man said.

"He is," Lestrade and Dimmock said at the same time.

The doctor – Bates, John thought – looked at John and raised his eyebrows.

"We need to stitch and bandage him, then I've been told he's being moved to a private room until they get all of his test results."

The tone of his voice told John that Bates did not like that. The order had come from higher up. 

Much higher up.

"Right," John agreed. He should disagree – Sherlock should stay in the A&E, but John didn't want to. Mycroft would ensure that things got done, that Sherlock got the best treatment. John, as a doctor, would effectively be Mycroft's man on the ground. He knew the system, and knew how to bully it into working for him. He wasn't sure he liked being roped into working for Mycroft though, even if it was necessary.

He wondered where Mycroft was. He would normally be there by now.

John wondered, then shook his head.

Dimmock wrinkled his nose again and John wondered if he had a cold or allergies, but it was the wrong season for allergies. But the younger man frowned, turning slightly toward Sherlock, and did it again. And again.

Not wrinkling his nose, John realized. Sniffing.

John sat up straighter.

"Everyone stop," Dimmock said, quietly, calmly, without trace of urgency, so that everyone did, turning to look at him. He held up a hand, ignoring the gazes directed at him, and sniffed again.

"What is it?" Lestrade demanded.

"I smell something familiar," Dimmock said. "John. Where's his coat?"

It had been bundled into one of the white hospital bags and put under the gurney. John pulled out the bag, passing it off to Dimmock with a questioning look. The agent only nodded thanks and opened the bag, pulling out a bit of Sherlock's coat and smelling it carefully. He pulled away with a frown, then did this again.

Then he glanced at Sherlock, frown deepening.

"What is it?" Lestrade repeated.

Dimmock ignored him, stepping one step closer to the gurney, dislodging the nurse from her position. He sniffed the air again, then shook his head, twisting a bit to glance back at John.

"This is going to sound weird. John, can I smell his hair?"

"His hair?" John asked.

"And his hands."

Everyone resumed their stares, only the tone of their expressions changed. Dimmock disregarded this as well, keeping his gaze fixed on John. John frowned, but if Dimmock of all people was making the request, it probably meant something.

"Um, all right, but please be careful," he said.

Dimmock nodded and stepped all the way up to the bed, evaluating Sherlock, then lifting his right arm from the wrist carefully and turning his palm up, sniffing it carefully. He blinked and drew back, then did this again before stepping up to the head of the bed and leaning over, inhaling when he was close enough to Sherlock's head to smell whatever it is he was searching for.

John thought it looked strange, but it was really not such an unreasonable request. He'd smelled his fair share of victims, for alcohol, vomit, other drugs, even perfumes or soaps. Dimmock wasn't a doctor, but he was an experienced agent.

"He's not been smoking, has he?" he asked, straightening again, looking at John.

"No," John replied, shooting him a puzzled look. "I'd notice that. Why?"

"Because he smells of cigarettes. Only faintly. But not typical ones. I recognize this smell. It's a French brand, Gitanes Brunes. Only they don't make them in France anymore, only in one place in the Netherlands, so they're not especially easy to get. Whoever did this was smoking these, probably right before going inside."

He almost smiled at John's stunned and questioning expression, but the light didn't quite reach his green eyes.

"It's the same brand and type my boss smokes," he said. "You work with it for eight years and you see if you can ever shake that smell from your memory."

He was still so groggy every time he woke up, dizzy and nauseous.

But no, John was being Doctor John and insisting and Sherlock hadn't the strength to refuse, even though he wanted to. Two concussions in the space of two weeks had made it hard to string a coherent thought together at first and John always caught him when the mood swings were bad, not making him snappy, but making him lethargic.

He hated sleeping this much.

He felt fine, he really did, except when he tried to do anything too strenuous, like move or breathe.

Sherlock rolled carefully onto his back, covering his eyes with his hand against the light that still seemed too bright even now, three days later. Without him intending it at all, a groan slipped past his lips and he tried to bite down on it, but too late. His lips were dry, chapped, he thought, which was uncomfortable.

John would have heard him and would be getting a glass of water and yes, there was the kitchen tap running then stopping and footsteps.

But that wasn't John.

Wasn't Mrs. Hudson, nor Mycroft, nor Dimmock.

Who? Sherlock thought, then swung into irritation that he couldn't identify the person bringing him the water and why on Earth had John thought it was a good idea to leave him with someone he didn't know immediately upon waking and where was John anyhow? What gave him the right to leave?

He was the one who had insisted on the trip to the hospital this time around, and was the one insisting on him resting. He should be here, taking care of Sherlock.

He forced his eyes open, but, the moment before he did so, he felt a light hand on his head, carefully avoiding the healing wound, and realized who it was.

"Lestrade?" he asked, his voice thick with sleep and the effects of the concussions, laced with disbelief.

Sherlock managed to move his hand from his eyes and something cool and smooth was pressed into it, a glass of water. He sipped it slowly, feeling him steadying it for him, taking his time to avoid any sudden nausea.

"How are you feeling?" he asked and he managed to focus, although his vision was blurry.

There was a chair beside the sofa, he noted. But he hadn't just moved it, or he would have heard it. He had been there awhile, watching him sleep.

"Fine," he assured him. "Why are you here?"

"You were attacked and you have another concussion."

Sherlock wrinkled his nose.

"I'm fine," he repeated.

He sighed, expression shifting to exasperation.

"You are not bloody fine, Sherlock. Two concussions in as many weeks. This is going to be the death of you and you are hardly any good to me or anyone else dead."

"Hardly," he replied. "Besides, they were unrelated."

"I know that," Lestrade answered. "But you need to take better care of yourself."

"I'm hardly to blame for some fool in a pub launching a poorly-aimed beer mug at me. Nor for a someone attacking me in a symphony hall."

Lestrade reclaimed his chair, watching him with strained patience.

"Honestly, it will get better," he said, ignoring the flare of nausea, because the damned painkillers had no say in what his body was going to do.

"I can take care of myself," he retorted. "I'm not a child."

He settled the empty glass on his chest and closed his eyes. The conversation had drained him in a way that was inappropriate but unavoidable. Everything did these days, although, admittedly, the days blurred together and it was only when he focused on what John had told him that he knew it had been three days since he'd been released from the hospital.

And he'd been in the hospital for a day and a half, which was more than long enough by his standards. They'd only discharged him because he tried to walk out on his own and John had agreed – reluctantly, Sherlock could tell by the way John related the story – to take him home and be responsible for him.

Well, he'd spent most of that time in bed or on the sofa, so he was behaving, according to John's standards, he thought. He was fairly certain he could not get into much trouble by sleeping, but not entirely. It seemed difficult to make these sorts of judgements right now.

He felt the glass being lifted from him and Lestrade went back into the kitchen, running more water. He returned and put the cool glass against Sherlock's hands, indicating that he should drink.

"Where's John?" he murmured sleepily.

"He's just gone out for a bit, which is why I'm here and hoping Donovan doesn't burn my station to the ground."

"Why?" Sherlock asked, trying to fight off sleep, feeling it creep back into his mind, his muscles, and the painkillers were making it too difficult to fend off. He groaned quietly, wanting just to stay awake for more than a few minutes at a time, wanting John to be there.

"He went for a walk. He needed a change of scenery."

What's wrong with here? Sherlock wanted to ask, but his mind refused to obey again and he went back to sleep.

John had thought getting out would be a good idea.

He'd bundled up and walked over to Regent's Park, taking the trail along one side of the boating lake, which had ice along the fringes already, although it was thin and almost completely transparent.

It felt good to be outside, in the chilly air and brittle November sunshine, and the movement had helped, making him feel more himself, less tired, less anxious.

For about ten minutes.

Then he realized that every time he passed someone, he was sniffing for the smell of the French cigarettes Dimmock had picked up on Sherlock's coat and hands and hair in the hospital. The cigarettes the attacker had been smoking.

Every single person, especially the men, was a suspect. When he actually did pass someone smoking, John would pause without thinking about it, trying to fit the scent of their cigarettes with the one the attacker smoked. Waiting to find the right person, so he could snag him, jump on him, tackle him to the hard, cold pavement.

It took a few more minutes to realize how much rage this inciting, how his shoulders tensed with each stranger who passed him by, how he clenched his jaw, how balled his hands into fists, how his short fingernails bit into the skin on his palms.

How he envisioned encountering the man, just so he could beat the crap out of him. With this, his hands itched, wanting to punch something – someone. For every blow Sherlock had suffered, John was going to inflict five of his own, good ones, straight to the man's jaw or nose or stomach. Over and over and over.

He had to stop and sit on a bench when he realized he was shaking, had to take a few deep breaths and close his eyes, refocusing himself.

It was a bloody miracle that Sherlock was not any worse off than he was. That he'd suffered no permanent, long-term harm, that his brain in his apparently thick skull had not been seriously battered to the point of actual brain damage. When the radiologist had come with the results and given them to John, Dimmock had had to catch him and steer him to a chair. John had been certain there'd be something. Swelling, bruising, bits broken off and floating around, he didn't know. Sherlock's hearing and, thank God, his vision, seemed all right, although he complained of ringing in his ears which was not unusual, and of blurred vision.

God, John thought. For all the things Sherlock put his body through, it was almost unbelievable he was still alive, let alone functioning, let alone still a genius.

Not that it seemed that way right now. They had the same conversation over and over, each time Sherlock woke up. What had happened? How long had it been? Did they know who had attacked him? John was getting sick and tired of repeating this continuously, and thought if it had not been for Dimmock and Lestrade, he may have lost his patience, not really at Sherlock, but at the situation that had caused him to be repeating these same questions.

Dimmock and Lestrade had kept him company at intervals, when they could, and had taken some turns babysitting – for lack of a better word – the detective so John could sleep or shower without leaving him unattended. Sherlock would have been better off in the hospital, but he never would have stayed. He'd made that quite clear by removing his IV lines and walking unsteadily into the corridor while John had been dozing between nurses' rounds. To offset them having to restrain him, which would have gone over poorly to say the least, John had signed him out and taken him home. Sherlock had somehow latched onto the fact that he had no actual brain damage, and had decided this meant he was good enough to be discharged.

Arguing with a concussed person was bad enough. Arguing with Sherlock with a concussion was like shouting at a brick wall to get it to crumble. A supreme waste of effort and time.

Occasionally, Sherlock was awake when Dimmock or Lestrade were there, and seemed confused by their presence, and then later, he would be puzzled by the fact that they had gone. He had no means of connecting time or events, although John could tell he was trying and was becoming frustrated with how difficult it remained.

Everyone was working on finding who'd attacked him. Lestrade had made sure that the skin under Sherlock's fingernails had been swabbed for skin cells that weren't his, since he'd obviously hit whoever had attacked him. Unfortunately, John knew that DNA took time, and it also required that the suspect be in the system from some previous crime in which he'd left DNA. The police had locked down the Barbican and interviewed all of the staff, but no one remembered anyone unusual or out of place. John didn't find this surprising – in a place that big, who would know? If  Sherlock could not identify him, since he remembered nothing from the incident.

Almost nothing.

When asked, each time, he would say he remembered violins and cellos.

Although this was impressive, because he didn't remember anything at all from the first concussion he'd taken almost two and a half weeks ago, it didn't help much. He'd been listening to a rehearsal session for the London Symphony Orchestra.

They'd been practicing some Mozart piece, from what John understood. And Sherlock played the violin himself. The fact that he had some patchy memory of this was not really surprising, and John wondered if it was a memory at all, or just a false memory.

Eventually, he got cold and got up off of the bench and kept walking, to get his blood moving again, to warm himself up. John tried to avoid glaring at the other pedestrians on the path, but everyone seemed suspicious to him. He almost laughed to himself when he realized Sherlock could probably have picked out which ones were genuinely feeling guilty about some real transgression. John felt like everyone was looking at him and bundled his hands into his pockets, trying not to pay attention.

He saw culpability everywhere, in a smile, in a laugh that passed him by, in a scowl, in a yawn.

Where the bloody hell are you? he asked the attacker silently.

With a sigh, he turned and made his way back, feeling no better for the enforced walk, but knowing he wouldn't feel much different back at the flat. Even with Mycroft's assurances that their flat was being watched for their own safety, even with Lestrade keeping people on it as well, he felt unsafe.

Because out there, someone was walking about, free, and had attacked Sherlock, had smashed his head repeatedly against an arm rest and had walked away, unnoticed, unremarked. He wouldn't feel better until that man was caught, and, unfortunately, he knew that was probably highly dependent on Sherlock improving enough to focus on something other than asking the same three questions, providing them with information that was probably lost to post-traumatic amnesia, or the attacker going after someone else and somehow slipping up, or someone who could identify the smell of the cigarettes actually stumbling upon him.

All in all, John thought, not very good odds.

"Et vraiment, je pense que– oh, you're awake."

Sherlock blinked rapidly, raising his head slightly. Dimmock was watching him from the dining room table, leaning back in a chair, his white shirt sleeves rolled up past his elbows and his suit jacket tossed casually over the chair beside him. He quirked an eyebrow at Sherlock, green eyes amused.

Sherlock half sat up, glancing around the silent flat. He listened carefully, but heard no other noises, no other voices that would have indicated anyone else was there.

Sherlock mentally shook away the vestiges of grogginess – it was getting easier now and, although he disliked admitting it, he'd been able to keep food and liquid down on a consistent basis.

His head still hurt almost all of the time, but at least it was tolerable now, and his vision was mostly clear and the ringing in his ears had faded. He knew he had more bloody healing itchiness to look forward to, as well as more fatigue, more mood-swings, more recovery time.

It was so tedious.

So was being babysat.

"Where's John?"

"Upstairs. Sleeping. Getting some real sleep. He's exhausted."

Sherlock found this unlikely. He himself had been sleeping a great deal, and John had been taking care of him, but it could not be hard to care for a sleeping patient. Could it? It's not as though he could require anything while semi-conscious.

"Who were talking to?" Sherlock asked.

"You," Dimmock replied.

Sherlock scowled.

"I was sleeping," he pointed out. He wrinkled his nose in displeasure; had Dimmock been trying to wake him? Then he realized that he disliked all of this sleeping. Could he dislike both the sleeping and the being woken at the same time? Interesting. He filed this away for future consideration.

"I know, hence my 'oh, you're awake' comment. Did you know you talk in your sleep?"

At this, Sherlock fell back against his pillow, ignoring the flash of pain in his head when he did that, because it wasn't serious.

Blast, now he knew? He scowled to himself; it had been bad enough when John had known, although Mycroft was also aware of it but he didn't count. John had told him that he was very coherent in his sleep, which was as it should be if he were going have conversations over which he had no control. He wondered if there were ways of combating this, or training one's self out of doing it, and resolved to research this as soon as they'd caught both the man who'd attacked him and this blasted serial killer with his message in the shades of blue of silk scarves.

"Stop grinning," he said to Dimmock without looking up.

"I'm not grinning," Dimmock said, obviously grinning. Sherlock looked up and shot him another scowl and Dimmock's grin widened.

"And we were having this conversation in French, were we?"

"Yes," Dimmock replied.

Sherlock sighed and pushed himself up, propping himself against the arm of the couch, reaching down for the glass of water that was kept on the floor beside him. Somehow, it was always full, and he supposed John had left strict instructions that it should be so. It felt like having servants again, and he disliked that sensation. It was his flat. Granted, John did the bulk of the chores, but John lived there as well and wasn't in Sherlock's employ.

"And do you plan on telling me what we were talking about?"

"Sheets."

"Sheets?"

"Yes, bed sheets."

"What? Why in the world would we be talking about bed sheets?"

"Don't ask me," Dimmock said. "You started it. Apparently, you felt it necessary to share your opinion on the subject. You seem to feel quite strongly that anything less than a one thousand thread count is not worth even being used as a duster – I bet you don't even dust – and that really, Egyptian cotton is the only fabric that should be used. I mean, I knew you were posh, but this is a bit above and beyond, isn't it?"

Sherlock glared at him and Dimmock kept grinning. He had been working, Sherlock could see, because there was a small pile of case files beside him on the coffee table, and he'd very carefully moved the scarves that were still inhabiting the table to make room for himself. He had a pen in his right hand and was tapping it absently against the notepad that sat in front of the files, the pen nib biting lightly into the yellow paper.

"I know what I like," Sherlock sniffed. "I can hardly help it if you have poor taste about these things."

"Actually I prefer any one-hundred percent cotton weave, doesn't have to be Egyptian, but it's nice to get the feel of satin without actual satin, which is just a pain because it slips around all over the place. Although I'm not picky about thread count like you are."

Sherlock stared at him.

Dimmock had grown with three older siblings and parents who had worked long hours for not much pay, lived in a tiny house in one of the frankly poorer suburbs, which did not especially lend itself to discerning taste in – well, anything. His undercover aliases had been similarly middle class and Sherlock had seen his flat, admittedly, Dimmock's own flat now was much better decorated and furnished. Sherlock had attributed that to the fact that he had chosen it for himself. And he had lived in France, but most of that time, he'd been hospitalized, and Sherlock strongly suspected that even French private hospitals were not quite that luxurious.

"What do you know about sheets?" Sherlock snapped, feeling annoyed that Sam had been able to surprise him.

The pause was a bit too long and Sam's eyes were suddenly a bit too dark.

"I was educated," he said shortly.

The hard look in Dimmock's eyes was all he needed to see to know just who his educator was. Sherlock had mostly refrained from asking for details about the captivity he saved him from but now he was unable to keep the unspoken questions from flashing across his face. He kept silent, trying schooling his expression carefully into nothing, trying to keep it that way despite the shock and dismay.

Dimmock stared at him, gaze still level, but he stopped tapping his pen and his grin was gone, vanished as though it had never been there. His fingers tightened around the pen, but not so much that his skin went white. His lips twitched, once. Sherlock wanted to shift, but sensed that movement now would be unwelcome. The silence drew out for a moment and Sherlock saw Dimmock tense and then force himself to relax.

"Fine," the younger man said. "Fine. After he paraded me around on the Strand for your benefit and that of the rest of the Met, he took me back to one of his flats. Don't ask me where, because he didn't let me see, and I was so doped up on scopolamine that it's hard to remember a lot from actually being outside, or in the car. I don't know if he had a medical degree or what, but he would drug me at precisely the right amount for just long enough that all of the things I don't want to remember, I remember quite well. Because I made myself do it, which seemed so hard, because I was so stoned."

"I don't think this was where he lived most of the time, but he probably had a dozen properties at least scattered about the city. Anyway, he handcuffed me to the bed – do you know, the headboard had some sort of hook fixed to it for handcuffs? Do you understand what that means? Wasn't just me, you know, not that this is really surprising, but I remember thinking something like Good Lord, he knows what he's doing, of course, by that point, I already knew that."

"Then he subjected me to a lecture on some of the finer points of life, such as thread counts in both cotton and silk – I can tell you those were silk – and how to tell the difference between hand-woven and machine-made for natural fibers and how British people have no good sense of sense, how we ignore the information our bodies, our skin, is giving us, how we refuse to actually appreciate or luxuriate in sensuality because we mistake this for sexuality and it offends our sensibilities. So we all walk around blind, according to him, or touch-less, I suppose. Oddly enough, I think he was right, but it was poorly timed for me, because then he assaulted me. For the fourth time."

Sherlock did not move and Dimmock was still staring straight at him, pen pressed against the yellow notepad, even harder now.

"I have this whole catalogue of 'the worst thing'. There's just too many too chose from. But that bruise I had on my face, that mark, do you remember? I got that from being pressed up against the radiator in that abandoned flat. That was the first three times. Just thank God there was no heat to that flat, or it'd have been a lot worse. Can you imagine? I'm telling you how it could be worse."

He paused, giving a flat, mirthless chuckle, eyes sliding away for a moment, then back.

"You know what another worst thing is? I bloody knew, Sherlock. I bloody knew from the moment I talked to you that it was likely to happen." Dimmock leaned forward, green eyes blazing now. "I walked right into this. Do you know, they always tell victims, this wasn't your fault? Do you know how hard it is to believe that when I was part of the set up? When I knew? And when I know I'd make the same choice over and over and over if I had to go back and choose again?"

"Why would you do that?" Sherlock asked.

"Out of stupidity and desperation. Because he had to stop. Because he had to be stopped. Because if you combined what I know about him, what you know about him, what anyone else who ever investigated him knows about him, I still think we wouldn't half understand his resources. Because he had a hook on his bloody headboard for handcuffs and I was not the first. But I was the last. Do you actually understand that? Do you actually understand that you were the only person who could stop him?"

"Yes," Sherlock said simply, a small part of him wishing Dimmock hadn't chosen now to have this conversation, when Sherlock was not especially at his best.

Had he done that on purpose?

It had always irritated him slightly that Dimmock was smarter than he let on, and he had wondered at the need to mask intelligence, why anyone would choose this. In the same way that he was quite good at keeping his expression neutral, he was good at keeping his level of intelligence neutral. Why bother?

Protection, of course, Sherlock thought. As a child from his older siblings, who were not as intelligent as he was, and as an adult from the people whom he'd been investigating under cover.

It was a good thing, Sherlock considered, that Moriarty had never got to Dimmock before Interpol had.

Then it annoyed him an irrational amount that he probably thought precisely the same thing about Sherlock – without the Interpol part, of course – on a regular basis.

"Right, now do you understand that he used unwilling bait and you used willing bait? He strapped bombs to five people just to draw you out. All I had to do was just wait. Because he couldn't lose. Up here, in his head," Dimmock tapped his forehead. "Not against you, certainly not against me. Not really. But when you're a cop – or a consulting detective or an Interpol agent – you do understand you might lose. Because we do, all the time."

"And what did you lose?" Sherlock asked, keeping his voice cool.

Dimmock tossed the pen down in front of him, leaning forward, arms on the table.

"Do you know what I did last year on October sixth? I smashed everything in my flat that I could. All the dishes, all the glasses, all the mirrors, all the picture frames. Everything. It took me three days to clean up and I cut myself more times than I remember, nothing serious, but I ran through an entire box plasters. Do you know what I did this year? I woke up in the morning and couldn't remember if I'd forgotten to buy coffee. I spent two hours doing the things I normally do – having breakfast, working – before I realized what day it was. So you ask me what I lost? Time. Maybe sanity, for a little while, yes. But you don't ask me what I gained. My life, Sherlock. Because he's dead. And how many other people have gained their lives back, too? You and John did. And how many others we'll never know about? So what, you want to know if it was worth it? Absolutely not. Absolutely."

He paused, then shook his head.

"Happy you know?"

"No," Sherlock said flatly. "Although I am glad you told me."

Dimmock was silent for a moment, the gave a dry chuckle, shaking his head again. But his eyes were lighter and there was some actual humor in his expression.

"You know, so am I," he said, slightly surprised. "Wouldn't have thought it."

He pushed himself to his feet and crossed the room.

"Give me the glass," he instructed and Sherlock passed it off. Sam went into the kitchen and the detective crossed his arms, appreciating the moment to digest what he'd just been told. It was not in the least pleasant information, but he did feel better for knowing. He did not know why this was.

Dimmock came back after a few minutes, having left the water run longer than necessary, giving them both some time to think, to let the subject settle and be put aside, at least for the time being. He passed back the glass and Sherlock sipped the water obediently – John seemed to have some sort of emotional investment in Sherlock being properly hydrated. He supposed that was probably an important thing in Afghanistan, in the heat.

He frowned, shifting through memories, not of John, of his own.

"Why do I remember cellos?" he asked.

"You tell me," Dimmock said, reclaiming his seat at the table. "You've asked me that before. John says you ask all the time."

Sherlock scowled; his memory was better now, but the first few days were hazy and patchy at best. His clearest recollection from that time was Lestrade's visit.

A creak from upstairs told Sherlock that the subject of Dimmock's last sentence was now awake, and John came down a moment later, sleep still clinging to the edges of his eyes, his hair askew.

Dimmock and John greeted each other comfortably, casually, and Sherlock noted the shift in Dimmock, as if their conversation hadn't happened, or, more accurately, as though it had eased something in the younger man and continuing it was no longer necessary. John went into the kitchen, asking if either of them wanted tea.

"Yes, please," Dimmock said and Sherlock just grunted. He knew he would get it whether he wanted it or not.

Dimmock picked up his pen again, then stopped suddenly, frowning. Sherlock paused as well, keeping his gaze, suddenly concerned, but he turned to stare at him, looking surprised.

"What?" Sherlock asked.

Dimmock blinked, green eyes puzzled for a moment, attention diverted. After only a minute or two, his expression lit up and he pushed himself to his feet, grabbing his suit jacket and pulling it on, then going for his coat and scarf. John came back into the living room, holding two tea mugs, but Dimmock shook his head with a smile and a light in his eyes.

"I'll be back shortly," he said. "There's something I need to try. Don't go anywhere."

This last was directed at Sherlock.

"I haven't gone anywhere in seven days," Sherlock complained.

"Well, don't start now," Dimmock retorted with a grin. "I won't be long. I have an idea."

"You know, you attract the strangest people," John commented after Sam had left.

Sherlock turned to stare at him, narrowing his eyes somewhat.

"How are you feeling?" John asked, running a hand through his short hair, which really only served to make it stand up more and in different directions.

"It's the bloody cellos again," Sherlock complained. "John, why can't I remember?"

"Because you were attacked," John said flatly, the smile disappearing from his face and eyes.

"This is hardly an uncommon occurrence," Sherlock pointed out.

"I do not want to be reminded," John muttered, almost under his breath, folding his arms over his chest. "Normally it doesn't land you in the hospital twice in two weeks, although it probably should, if you had anything remotely resembling concern for your health."

"I'm very concerned," Sherlock countered. "I'm drinking my water, aren't I?"

John snorted, still displeased. Then he sighed, crossing the room and perching on the arm of the sofa behind Sherlock, forcing the detective to shuffle forward carefully, the glass of water still in his hand.

"Let me have a look," he said and put his fingertips on Sherlock's head. With a scowl and an inward sigh, Sherlock held still, letting John poke and prod – very carefully – at the stitched and healing cuts. Now, of course, there were two, and John had told him he was lucky it wasn't more.

He didn't feel particularly lucky.

"Well, no bits of brain leaking out," John said.

"Oh, please," Sherlock said. "I hardly think that's appropriate bedside manner."

"Well, you are an especially stubborn and belligerent patient."

"I am neither stubborn nor belligerent," Sherlock snapped, realizing then that he sounded both by saying that. "I've been listening to your instructions very carefully and sleeping and all that rubbish. I feel fine."

"Uh-huh. Until you stand up and get dizzy or try to read something for more than a few minutes. If I didn't have people watching you when I have to sleep, you'd probably be down at the Yard right now harassing Lestrade or hunting down criminals on your own."

"Honestly," Sherlock said, twisting his head back to see John somewhat. "Your bedside manner is really atrocious."

"Have you eaten anything since Dimmock's been here?" John asked.

"No," Sherlock said in a voice of strained patience. "I've been sleeping almost the whole time."

"All right, I'm going to make us both something to eat, then."

"I don't understand why I can't sleep with you when you're asleep," Sherlock complained.

"Because then no one can keep an eye on you."

"If I'm sleeping, surely I don't need keeping an eye on."

"Only until you wake up and I don't," John replied. "At any rate, you're much better than you were, so you can probably start picking up your old routines again. Slowly."

Sherlock wrinkled his nose as John slipped off the sofa and went into the kitchen. He fixed them some omelettes and tea and Sherlock ate slowly, not really hungry, mulling over the conversation he'd had with Dimmock, wondering where the agent had gone, and what had sparked the sudden realization in his eyes before he'd left.

It was about an hour before Dimmock returned, John letting him in downstairs. He clattered up the stairs ahead of the doctor, grinning triumphantly as he stepped into the flat, holding up a small blue package.

"Cigarettes?" Sherlock asked.

"What?" John asked from behind Sam, locking the door behind them.

"Yes," Dimmock said to Sherlock.

"Well, this is more like it," Sherlock replied and Sam snorted.

"Not for you," he said.

"Then who? You? You don't smoke."

"Yes, I know," Dimmock replied. He shrugged off his coat and suit jacket again, tossing them over Sherlock's chair. "But I recognized the smell. This is what your attacker was smoking."

"Yes, you've told me that, and I remember you saying so," Sherlock replied.

"What's the strongest sense associated with memory?" Dimmock asked.

"Smell," Sherlock replied promptly, then shot a look at John, admonishing him for his surprised expression. "Oh, of course I know that, it's actually important. It can be used to trigger recollections from witnesses and – Aha."

"Right," Dimmock said grinning. "If I remembered it, you might, too. John, can you get me a lighter?"

He flipped the packaged upside down on the end table, tapped it once, then opened it, pulling out one of the cigarettes as John went into the kitchen and rummaged for a lighter.

"Get me an empty tin or something, too, so I can keep the ash from going all over your floor," Dimmock called. He put the rest of the package down and then put the cigarette between his lips, accepting the lighter from John when the doctor came back.

"Do you actually know how to smoke?" Sherlock asked.

"Tried it when I was a teenager. Disgusting. This is going to be worse, because it's stronger."

"It would be much simpler if I did it," Sherlock said.

"No!" John and Dimmock said in unison, John more forcefully, Dimmock's voice made somewhat indistinct by the cigarette between his lips. Sherlock looked at it longingly and sighed, even though Gitanes was not his brand. He was perfectly willing to try it. For the sake of experimentation, of course.

Dimmock flicked the lighter and held it to the end of the cigarette, inhaling lightly until the flame caught. Then he coughed, pulling the cigarette out and making a face.

"Ugh," he said. He tossed the lighter beside the open package and took another drag, this time more carefully, wincing as he did so. "Good Lord, that's disgusting," he complained as he exhaled a puff of smoke between his lips. "This is the most foul thing I've ever tasted. Here, pass me that glass."

John passed off the empty glass he was holding and Dimmock moved around Sherlock's chair to lean against it, closer to the sofa. He held the cigarette between his index and middle finger and tapped some of the ash inexpertly into the glass. John snorted, probably at the expression on Sherlock's face when the detective twitched his eyebrows upward in disapproval.

Dimmock smoked the cigarette, making faces the whole time, letting the scent fill the flat. Sherlock closed his eyes, ignoring John, who clearly had mixed feelings about this, ignoring Dimmock, who was trying not to cough or complain. He inhaled deeply and slowly, teasing apart the scents in the smoke, willing his mind to remember. The air filled enough that he could inhale the faint aroma each time he breathed, and he could tell by the change in the pattern of Dimmock's breathing that he'd finished. This was accompanied by his footsteps retreating to the kitchen and the tap running for a moment as he fetched himself a glass of water.

Sherlock could feel John's eyes on him the whole time, but ignored this through practice, keeping himself very still.

The scent nudged at his brain.

"What?" he asked himself.

He remembered it suddenly, yes. Clinging, almost cloying, unaccustomed pungency in the near-darkness.

Accompanied by the presence of another person in the shadows, a silhouette, really, sitting further away, then coming nearer, but there seemed to be no threat in this memory, no sense of warning.

Violins and cellos.

Sherlock pushed this away, because it was unnecessary and distracting, although yes, he remembered the orchestra now, the sounds of the music.

Music interrupted by someone else.

Sherlock frowned without realizing it. He'd never had anyone find him, disturb him, while he was listening to rehearsals.

Had he been tracked?

But no, there was too much surprise in the memory of the voice. Which seemed familiar.

What had they talked about? He'd have sensed some warning in the air, had it been there, of course. What was the surprise he recalled in the memory of that voice?

He took another deep breath and his eyes flew open, shocked, and he met John's gaze.

"The violinist."

"The cellist," he said, and of course that was why he'd remembered cellos. Had forced himself to remember cellos. When he could cling to nothing else, he'd compelled his mind to hold onto that one thing, that memory that made no sense on its own but was clear now, so obvious.

"What?" John asked.

"The cellist, it was the cellist."

"What, from the LSO?" John inquired, giving Sherlock a confused look.

He shook his head quickly, ignoring the faint dizziness that accompanied this, pushing himself to his feet, looking between Dimmock and John.

"No, from Angelo's. You weren't there, John. It was three weeks ago now." He stared at John, surprised, then felt his eyes widen. "Yes, yes, of course, how could I have missed it? Music, it was the music. That's how he found the first London victims, Clayworth and–" he snapped his fingers, irritated at the lag in his memory. "Assad. He found them that night, oh it's bloody obvious, isn't it?" he reprimanded himself. "He told me he was playing in the area that night!"

Oh he was flying now, he could feel it all coming back, and it was brilliant, absolutely brilliant, his mind finally taking control back from his blasted body and the blasted concussions and all of the nonsense that accompanied the injuries. He felt focused for the first time in weeks, felt the whole case coming together, spreading out around him, bits and pieces snapping in place like they should be so that he could almost see the pattern, almost hear the other man's thoughts as though they were his own.

"Wait, aren't we talking about the man who attacked you?" John asked. Dimmock was watching with his eyes narrowed, looking equally as confused.

"Yes, yes," Sherlock said, crossing the room, dismissing the twinges of dizziness, because they were not important right now. He pulled out the files on the first London victims, flipping them open, scanning through them. "Yes, we are. It's the same person, gentlemen, the man who attacked me, the cellist I met at Angelo's, he's our killer."

Dimmock and John both stared at him, disbelief scrawled on their features.

"What?" they demanded at the same time.

"This is why, don't you see? of course you do not. I gave him the phrase, his message," Sherlock stabbed a finger at the felt-marked glass and both other men turned to look at it. "I remember now! Brilliant, Dimmock, brilliant! I'm sure you deserve a raise."

At this, Dimmock snorted, crossing his arms.

"But how did you know it was him?" John asked.

"I didn't, not right away. He said something about–" Sherlock paused, massaging his forehead with his fingertips, trying to jog his memory. "Something about the orchestra rehearsing to an empty auditorium and how he disliked that. I just said it. Neither of us knew."

He was certain about that, now. He remembered it quite clearly, the pause in the darkness, the moment of jarring realization, the sudden rush of adrenaline evolved to keep him alive. A defense against predators. Different sorts of predators, now.

"How did he find you?" Dimmock asked.

"He wasn't looking for me," Sherlock said. "I just said, neither of us knew. He was just there."

Dimmock stared at him and John shook his head, holding his hands up in a universal gesture of surrender, although to what, Sherlock didn't know.

"How is it that you still manage to draw these maniacs out?" John muttered.

"I went for the music, John. So did he," Sherlock replied shortly, still scanning the file. "We'll need to track down any sort of concert or show all of these couples attended before they were murdered. And match them up to any performances our killer was giving."

"It would help if we knew who he was," Dimmock said and Sherlock glanced up to see the agent watching with crossed arms. "He wasn't quite kind enough to leave fingerprints on any surface that wasn't already marked with dozens of fingerprints from audience members. Do you think you could describe him to a sketch artist?"

Sherlock snorted.

"Honestly, Dimmock, you're such an agent," he complained.

"Uh, yes, I am," Dimmock agreed. "It is my job."

"I can do even better," Sherlock said, grinning, noting how both other men disapproved of the grin, John's expression dark, Dimmock's annoyed.

"I can give you the sketch artist who actually saw him."