Disclaimer: I do not own these characters, and am making no profit from their use.
Warnings: Disturbing concepts, including suicidal ideation, lobotomy, gory experimentation and emotional manipulation.

Spoilers: For all of seasons 1 and 2. Disregards Season 3.

Empathy

Part One

empathy (noun)

1. The ability to understand and share the feelings of another

xx

John always found it hard to pin down exactly when he'd realised what he was doing was out of the ordinary. When you were a child, you thought your world was the only world that existed, that everything that happened to you and everything you did was normal, and no one ever experienced anything differently. Gradually, through comments of 'you can't possibly know that John', 'what an imagination you have' and 'stop lying' he became aware that no one else knew what other people were feeling all the time.

They could tell, of course, from facial expressions and voice tones but they didn't know, not in the way John did. They didn't feel a faint curl of sadness in the back of their mind when someone was crying, they didn't feel a flicker of embarrassment and shame when someone tripped over in the street, and they couldn't cheer someone up just by thinking really happy thoughts at them.

And as he'd gradually realised this made him unusual, made him different, John started trying to hide it. At first because no one believed him, but then because he was frightened they'd take him away and lock him up in a laboratory somewhere. He once saw a movie that involved a man getting a lobotomy, and had nightmares about it for years afterwards.

So his first reaction to Sherlock's deductions wasn't affront or offense, but shock, awe and a tentative hope. John had tried to squash it, tried to tell himself to be calm and logical about it, but nothing could silence the tremulous question in the back of his mind.

Is he…like me?

But eventually, he learned that Sherlock wasn't like him. He was just clever; very, very clever. It was still fascinating and amazing and brilliant and all those things, of course it was…but it was also a little disappointing. Just a little, just in the secret corners of John's heart.

He used to ask people about it. He'd talk about auras, about psychics, and ask people if they believed it and then watch them, feeling about for a flicker of acknowledgement or fear or recognition.

But it never came. John was alone.

And perhaps that was a good thing. John called what he was doing – or had done, because he was holding to his vow not to use it again – empathy. It wasn't telepathy, because he wasn't picking up on people's thoughts, only their emotions, and it wasn't clairvoyance because he wasn't seeing the future, so empathy was the best descriptor he could come up with. But whatever it was, it could do its fair share of damage. And after Thomas, and Kemp…well, it was probably a good thing he'd never found anyone else like him.

Wouldn't want too many monsters running around, after all.

xx

"So, you'll stay." It was phrased as a statement, but John could feel the way anxiety suddenly shot sticky black needles through Sherlock's voice.

"Of course I'll stay," John snorted, picking over his fried rice to see if any more of those tasty shrimp pieces were lurking around. "I don't shoot people for just anyone, you know."

"Patently untrue – if it were a good cause, you would do whatever you deemed necessary."

John could concede that Sherlock was right about that; the shooting part, at least. But before the shooting, John had used his empathy.

It wasn't much. Just a little nudge of concrete-thick confusion and hesitation to slow Sherlock down, make him pause before swallowing the pill, buy John time to get his gun out and load it. But he'd still done it – a vow he'd sworn to uphold, that he'd stuck by for over six months, and he'd thrown it out the window as soon as Sherlock was threatened.

He should probably be more concerned by that. But he couldn't regret it, not really – he liked Sherlock. The man's emotions were just so…honest.

People (indeed, Sherlock himself) might claim that the man was emotionless, but he wasn't. John might have tried to suppress his empathy but he still felt Sherlock's emotions leaking out of him, wavering through the air like heat shimmers. Sherlock had emotions, of course he did, but he was more controlled about them than other people. At least, those not linked to frustration or excitement – those were always on clear display.

In many ways, it was a relief. Other people got angry, then pretended they weren't because they didn't want others to think they had a temper. Other people were sad, and pretended they weren't because they didn't want to share their grief with the world. Other people were amused, and then tried to pretend solemnity, because they didn't want people to think they were morbid or weird. Other people hated, and pretended fondness because it was politic. Other people pretended, full stop, and the mixed signals – the confusion between what his empathy was telling him and what his eyes and ears told him – often gave John headaches.

There was never any kind of confusion with Sherlock, and it was refreshing. Correction, it was bloody magnificent, and John knew he would have put up with a lot worse than casual insults and disregard for his personal autonomy just to tag along after that kind of clarity.

He needed to be careful with this.

xx

"Do you object to rich bankers in general or Sebastian Wilkes in particular?"

John turned his head, jerked out of the breathing exercise he'd been engaging in to try to calm himself down. "What do you mean?"

You don't like him," Sherlock observed. "You barely spoke to him, and didn't shake his hand when we left."

"Yeah, well, he's kind of an arsehole," John muttered. He couldn't say that Sebastian's frustration had scraped over him like piano wire, setting his teeth on edge like fingernails dragged over chalkboard.

Physical contact always enhanced his empathy (that handshake had been a mistake), but he might have dealt with it better if he hadn't had to make a grocery run earlier that morning.

Really, this was just one more example of how this whole thing was more curse than gift. If John didn't have his empathy, he might have stood a better chance at keeping his head when he was dealing with the stupid chip and pin machine.

But he always got so frustrated in grocery stores; so many other people were rushing around –frantic to pick up tonight's dinner before their kids got off school, wishing the line in front of them would move just a bit faster, cursing the customer in front of them for taking the last bit of smoked cheddar – that John couldn't help but pick up on it. He always tried to make his shopping trips short because after twenty minutes he started to become restless and impatient, like he was inhaling that cloud of frustration and it was slowly permeating his blood, an emotional form of passive smoking.

The tube was another problem place for much the same reasons, which was why John preferred to walk and didn't grumble (much) over Sherlock's love of cabs.

So shaking hands with Sebastian at the bank ended up putting him in a very foul mood. Sebastian was brimming with resentment and thwarted ambition and god, why were so many people so unhappy? There were times when John thought city life was just inherently unsuited for the human race, and everyone should move back to the caves and start over.

"You're tense," Sherlock observed. His voice was quiet, probably meant to be soothing, but John's muscles only bunched tighter.

"Yeah, just…" John shrugged, and told a partial truth. "Too many people."

Sherlock made a soft humming noise that John assumed was either understanding or considering. But when they hit the tight crush of the street, John couldn't help noticing that Sherlock was manoeuvring himself to stand between John and the worst of the crowd.

xx

John had always known he could make his emotions bleed into other people, and he'd always tried to push positive emotions to make people happier and more relaxed. If he was going to influence people like that, he might as well make it a good influence, after all. At least until…Kemp.

That had been the first indication of how dangerous his empathy could be. Before Kemp, John had never really thought to use it as a weapon.

But he used it as a weapon now – there was someone else in the apartment with Sherlock, someone who smelt of smoke-sharp frustration and oily-bitter determination – and John knew he needed to do something. He pounded on the door and vented some of his frustration, trying to get Sherlock to let him into the apartment.

When Sherlock's monologue cut off, emotions fracturing into glass splinters of terror, John knew it was time to stop messing around. Kicking in the door would take too much time (and to be honest, John wasn't entirely sure he was physically capable of it), but there was something else he could do.

John dredged up all the fear he was feeling – along with the memories of every moment he'd ever been scared or hurt – and threw them all at the foreign signature above him. He wrapped the stranger in them, smothered and drowned them beneath unreasoning, unquestioning fright until rational thought was erased and all that was left was the instinctual response.

Run.

John felt the person flee, and smiled grimly to himself.

He'd broken his vow again. And again, he couldn't bring himself to regret it.

xx

John spent several minutes mulling over how best to approach the matter, but in the end just decided to go for the bulldozer method.

"How bad is your throat?" he demanded.

Sherlock didn't start, but his face twitched like he was surprised. "My what?"

"Don't play stupid, it doesn't suit you – your throat, how it is?"

Now Sherlock was looking intrigued. "How did you know?"

John couldn't exactly confess that he'd been able to sense a second person in the apartment, so he went for the next best thing. "Your little deduction-rant cut off and now your voice sounds hoarse; it's not much of a leap to think something happened. Did you suddenly develop a cold?"

"There was someone in the apartment, he tried to choke me and he left this," Sherlock admitted, pulling out a folded black lotus flower and speaking very rapidly as though he thought he could distract John.

John gave into an impulse he'd been feeling for a long time, and reached up to cuff Sherlock across the back of the head. "You see? You see? This is what happens when you lock the trained soldier out of the apartment!"

"I didn't know he was in there," Sherlock protested.

"And that's why you take me!" John hissed, keeping his voice low.

Sherlock huffed and said nothing, which meant he knew he'd made a mistake and didn't want to admit it.

John knew he should leave it at that – he'd broken his vow too many times already. And in spite of what he'd used to think, he clearly didn't have control over this facet of his ability – Thomas had proved that.

But on the other hand, he could ease Sherlock's pain, ensure there were no complications…

God, he was like a drug addict, always making excuses. Besides, it probably wouldn't work.

But John already knew what he was going to do. "Come here, I can do something for your throat."

Sherlock looked vaguely suspicious. "If it involves drinking some sort of horrid liquid-"

"Do you see a tea kettle tucked under my jacket? Now shut up, come here, and trust me."

To John's surprise, Sherlock did just that, stepping well into his personal space and staring down at him with an air of expectation. He radiated a tangy sort of curiosity, the low engine-thrum of excitement that was presumably about the case, bright sparks of bitter pain from the attempted strangling and a rich, bright glow of simple, uncomplicated trust.

It had been a while since someone had felt that sort of thing for him, and John needed a moment to compose himself before he reached for Sherlock's neck. He pushed the scarf aside and laid his fingers over the reddening mark, massaging it gently.

Then he took a deep breath, and reached for Sherlock's pain.

The first time he'd done this, he'd been twelve and their dog – Gladstone – had wriggled under their fence and been hit by a car. John had been the one to find him, and he'd taken the whimpering puppy in his arms, for a moment wishing that he could take the pain himself…

And then agony had roared through his body. John had passed out on the spot, and woken to Gladstone licking his face. The dog had been whining and wagging his tail, and moving like he'd never been hit by a car at all. The previously mangled back legs were as straight and healthy as they'd been that morning, and only the blood on Gladstone's fur and in the gutter told John he hadn't imagined the whole thing.

It had taken John years to understand what he'd done. Somehow his ability to feel and influence other people's emotions translated to being able to heal them as well. John wasn't sure how that was connected, but it only worked if he was willing to take on the pain of their injury. And not just the pain of the infliction, but all the pain they would have gone through as it healed, compressed into the space of perhaps a minute. It didn't work if he told himself his patient was going to die unless he healed them – his empathy had never been influenced by logic, after all. He had to care for the person enough to be genuinely, instinctively willing to take the pain from them, which made the number of people he could heal very limited indeed.

But Sherlock was one of them. At least, John was fairly certain he was one of them.

He was proven right when pain raced through his throat, sharp and sudden. It felt like his neck was collapsing, his throat being scraped raw as every little hurt or twinge Sherlock would have experienced until the bruises vanished rushed through him in the space of a minute.

Good thing he was used to this. John kept his head ducked to hide the grimace, and swallowed rapidly to try to quell the lingering soreness.

"That was very quick," Sherlock said, so abruptly John twitched.

He probably should have drawn it out, massaged a bit longer to make it seem believable, but it was too late now.

"Pressure points," John lied. "Those years of medical school are good for something, you know."

He allowed himself one last stroke of his thumbs across Sherlock's throat, checking that he'd healed it properly, and was surprised by the silk-shiver of desire that hissed up from Sherlock to greet him.

Startled, John glanced up at Sherlock, but the detective's face was turned away, staring up at the house he'd just left.

It was a little disappointing, but not terribly surprising. Just because John's empathy meant he knew Sherlock leaned more towards celibate than asexual didn't mean he wanted John, and feeling desire for someone was a far cry from actually wanting to have sex with them.

And when someone was feeling so affectionate and in love it felt like trilling birdsong and cotton floss sticking to the sides of John's mouth, it didn't necessarily mean they were in love with him. Mary had taught him that lesson. It had been painful, but not nearly as painful as the lesson Kemp taught him. Or when Thomas taught him the final lesson, the one that made him give up his empathy as a bad job, a mistake, some freaky mutation in his genes that should never have happened in the first place.

Yet…this was the second time he'd used his empathy to save Sherlock's life. And maybe, if was very careful, he could use it to heal people again.

But just small things. Nothing like Thomas. Nothing like that ever again.

John was uncomfortably aware he sounded like alcoholic pleading that they only drank on special occasions.

xx

There hadn't been many times in his life that John had been glad to go home alone after a date, but this was one of them; being knocked about the head didn't make for a good night.

John brushed his fingers over the gash behind his ear, held together with three stitches. It stung painfully, and he quickly withdrew his hand – it wasn't a terribly large injury, but the scalp was very sensitive.

"They said you didn't have a concussion," Sherlock said. "You could have gone home with her."

He sounded grumpy, but John could feel the guilt and worry Sherlock was stewing in, thickening in his lungs like noxious smoke.

"It was the first date," John pointed out. "Whatever impression Mike may have given you about my dating prowess, I'm not in the habit of taking people to bed that quickly."

"He did mention something about three continents," Sherlock smirked.

He seemed amused, but there was a bitter tang of envy beneath there, along with scouring prickles of something like resignation and a thick blue flash longing. In short, it was far too much for John to sort out after he'd come close to having his skull bashed in.

So he ignored it and grimaced at Sherlock to express his disdain of that stupid nickname Murray had saddled him with.

Most of his friends had been astounded by his so-called 'success', but John couldn't really take any pride or satisfaction in it. His empathy ensured he always knew when someone was genuinely interested in him, and often warned him when he was starting to do something that would put them off. He had a small window into people's minds while everyone else was stumbling around with conversational cues and body language – of course he seemed like some kind of Casanova by comparison. Which sounded brilliant, but in reality was often just messy and painful, and ensured a one-night stand was almost an impossibility for him – other people might have been able to have sex with people they were essentially indifferent to, but John had to genuinely like them. He'd tried going to bed with people he didn't really care about on only two occasions, and each time the near-constant contact with their emotions his empathy provided made him tense and frustrated, like a cat having its fur rubbed the wrong way.

He didn't feel that with Sarah, though. She was...well, nice. Her emotions were sweet and clear and honest, like the peal of a chapel bell.

People's emotions changed, of course they did, but everyone had their own…signature, for lack of a better word – a strange mishmash of sight/sound/smell/taste/touch along with something else, something beyond those five senses, something that was purely his empathy. The emotions might vary, but the signature stayed the same, and in John's mind, Sarah would always be linked to the image of a church bell sounding out the dawn.

John's mother had felt like a meadow, like soft grass and pastel flowers with little insects buzzing over them. His father had felt like cloth, like threads of all different colours and textures weaving together, sometimes separate, sometimes blending to create something entirely new. Harry felt like a jewel, like a bright red ruby set in cold silver, all sparkling and sharp, sometimes so bright it hurt his eyes.

It meant he was able to identify people with his empathy – when he was a kid, John had always known when Harry was coming home from school because he could sense her walking down the street – but only if they were familiar to him. After all, he'd had no clue he and Sherlock were apparently being followed for days. And it hadn't warned him he was about to be kidnapped; empathy wasn't telepathy, and while he'd been able to feel that their kidnapper was metal-bright determined and resolved, there had been no fireworks of anger or hatred to warn John they were in danger.

At least he'd known not to panic and try some last-ditch, suicidal escape plan when he felt Sherlock coming. He'd felt him from almost half a mile away – Sherlock's signature was very...unique. It always made John think he was standing in the midst of a labyrinth of caves – immense and intimidating and sparkling with astonishing crystal formations, fading into shadows and hidden depths.

Though something about Sarah seemed to irritate Sherlock for some reason. John couldn't pin down why – the cavern of Sherlock's emotions got dark and flooded and choked his throat when Sarah was brought up. There was the gritty silt of irritation, yes, some vague sharp flavours of jealousy (probably resenting those moments when he wasn't the centre of John's attention) and something that felt puzzlingly like shivering insecurity and resonating loneliness, but that was as much as John could make out.

Sometimes, John wished everyone's emotions were exactly the same, instead of the billions of shades and nuances and mixtures they actually were – he'd probably have managed to sort out every possible combination by now if that was the case.

But he wasn't that lucky, and instead he was stuck with strange echoes of feeling and a whole lot of confusion.

Just like everyone else. Well, not really.

xx

If Sarah was a church bell and Sherlock was a winding set of caverns then Molly was like a river. Clear and calm apart from the occasional floods and flurries, and far deeper than it looked.

But the man with her was different. The happiness and excitement were genuine, but they seemed thin, as insubstantial as mist drifting across…nothing. A gaping hole like an empty grave, like someone had reached inside and cut out everything inside him.

John did his best not to touch Jim or look at him. He was almost grateful when Sherlock told Molly he was gay (almost, because really, that could have been done with a lot more tact) because at least she'd been warned off him. And John doubted anything he said would have made an impact – what could he have said, after all? He didn't think a 'sorry, but your new boyfriend feels like the kind of person who'd kill people just for fun' would go down well.

He'd still considered saying something, but then he remembered how wrong his empathy had been about Kemp, and kept silent.

Still, considering that introduction, he wasn't entirely surprised when he woke up in the pool changing room, his hands cuffed to the railing, to find Jim grinning down at him. He stared for a moment, then made himself look away, trying not to get sucked down into that black emptiness.

"What, no exclamation of surprise?" Jim drawled. "I'm disappointed, Johnny – don't tell me you don't remember me."

"Jim, dating Molly, works in the IT department at Bart's and seemingly gay," John recited wearily. "Though I'm assuming none of that is actually true, and that the name 'Moriarty' means something to you."

"He fell for that little trick with the underwear then, did he?" Moriarty giggled. "How delightful."

John wasn't surprised to learn it was a trick. He didn't think Moriarty was gay – he didn't think he was anything, really. He think Moriarty could be anything, not with that…emptiness.

He made himself look again, made himself stare into that yawning void and couldn't help but wonder what had happened to make Moriarty like that.

Something must have shown on his face, because Moriarty's expression suddenly went blank and flat, dead eyes glittering like a shark's.

"Is that pity I'm seeing on your face?" Moriarty hissed, leaning in close. "Pity? When you're the one about to be strapped to a bomb?"

John had no idea what Moriarty was seeing, but it probably was pity. Because he looked at this man, this man who'd killed so many people just to attract Sherlock's attention, and the main thought in his head was 'you poor, sad sod'.

"Don't you dare pity me!" Moriarty suddenly snarled, slapping John across the face.

John automatically turned his head to absorb the blow, absently noting that Moriarty clearly wasn't used to hitting people. He had slapped John instead of punching him, and it was a rather ineffectual slap at that – just a sharp sting, and it probably wouldn't even bruise.

It was loud though; a sharp smack of flesh against flesh, and the sound seemed to restore Moriarty's composure. He stepped back, straightened his suit, and grinned.

"You already know how this works, so I won't bore you with the details," he said, tossing an earpiece into the air and catching it again. "Do exactly as I say, say exactly what I want, and I might let you live through this."

With anyone else, John might have been able to tell if they were lying – there might have been a sharp, illicit thrill at the idea of making him dance to their tune when they were just going to kill him anyway, like the icy point of a needle pricking his thumb. There might have been smugness, thick and rich like melted chocolate, there might have been stinging-sandpaper guilt or chili-scented anticipation or something. But with Moriarty, that emptiness offered him no clue, no hope, not a single shred of insight.

He hadn't seriously pushed anything on anyone since he'd made that Lotus bloke run away from Sherlock. The slight nudges to Sherlock when the detective was in one of his moods were always half-hearted, always tinged with the thought that Sherlock would come out of it eventually, and maybe he should just leave him to his sulk. But now, staring into Moriarty's face, John gathered all the fear and despair he was feeling and pushed.

And it was sucked into the emptiness like light going into a black hole. There and then gone, without leaving even the slightest impression.

The feeling of his emotions spiralling away into the void left John feeling like he was standing on the very edge of a very tall building. Sick with vertigo, the drop making him feel dizzy, and he jerked his gaze away from Moriarty before he vomited.

And he did exactly as Moriarty ordered.

Maybe this was what he deserved. John didn't really believe in karma or some kind of cosmic justice, but maybe this was his punishment for what he'd done to Thomas.

xx

Afghanistan had been when John began to understand other, less pleasant aspects of his empathy. Well, it was hardly pleasant to be able to feel people's misery and pain simply by virtue of close proximity, and Kemp had shown him that his empathy could have devastating consequences, but he'd never considered that his empathy could truly be a weapon before.

Until he found he could create a neat hole in firing lines by pushing fear and despair like mustard gas onto the enemy soldiers, to the extent that they dropped their guns and cowered while he ran to treat the wounded. Until he realised he could raise the flagging spirits of his comrades with some subtle nudges of hope and courage and happiness like sweet-smelling coffee. The officers always liked it when he came around, saying that everyone seemed much happier after he'd visited.

John always laughed it off and gave some weak excuse about being a people person. It wasn't the first time he'd noticed this side-effect of his empathy – even when he wasn't deliberately trying to influence others, he seemed to instil a sense of calm and relaxation. He wasn't sure why, but it was very useful when treating patients – they had to be well and truly worked up before they even started to get nervous.

He also found it easier to heal people in the army. You were much more motivated to take on a comrade's pain than an acquaintance's. And for a while, it was good; he was healing people, and he'd finally found a use for his empathy – there was actually a point to picking up on people's heartbreak and terror.

Then John fucked up, and it changed everything.

Thomas was ginger and freckled, and burned whenever he forgot his sunscreen. He seemed to find the whole thing more funny than irritating, though, and grinned at John whenever he asked how he was doing. He had a habit of looking up at John through his eyelashes, and he shared the care packages he got from his parents, and John thought maybe, maybe…

Then Thomas tripped a mine when they were scouting the road for a convoy.

John managed to tackle him off it, but half of Thomas' right leg had been blown off. John had automatically put pressure on the injury, reaching for Thomas' pain to heal him, in that moment not even caring if half the bloody squad saw what he was doing.

But then something had hit his left shoulder like a hammer, and John felt himself falling. He felt his link with Thomas fading, his own pain overwhelming his empathy, and in his panic he grabbed for every ounce of Thomas' pain he could feel and pulled.

John passed out on the spot. And when he awoke, he had a hole in his shoulder and a pending honourable discharge for medical reasons. All of which he didn't really care about at the time because they'd had him on some very strong drugs.

They began to wean him off the morphine on his second day of consciousness, and it was then that his scattered thoughts came together enough to ask about Thomas and if he could see him. His doctors weren't happy about it, but John promised quite faithfully to be a good patient as soon as he'd seen Thomas, and threatened to be as difficult as possible if he wasn't allowed to. Which wouldn't have worked back in London but this was Afghanistan, and perhaps it was a bit unethically sound to take advantage of overworked medics, but John didn't care.

"It's not pretty," was Dr. Nguyen's warning. "His leg's fine, but we think he has brain damage."

For a moment, John had been sure she was joking. "Brain damage?"

Nguyen nodded. "He seems to be catatonic. We'd need someone to get a look at him and make sure it's not trauma related, but…"

She shook her head and sighed. "I've seen catatonic people, and he isn't catatonic. I honestly have no idea what's wrong with him, but brain damage is the most likely explanation."

John's chest clenched in dread, and he was grateful she left him to enter the room alone.

Thomas was sitting on the bed, staring at the wall, and didn't even glance at John when he entered the room. Very much like a catatonic patient, except for the small smile and almost blissful expression on his face.

"Hey, Thomas," John said, not really expecting a reply.

Thomas didn't so much as blink. But John wasn't deterred – if the brain damage was physical, maybe he could heal him?

He sat beside Thomas bed on the bed, and took his hand, reaching for his pain…

But there was none. No pain, no damage, no trauma, only pure contentment.

John had taken Thomas' pain. But not only the physical, as he'd intended to – he'd taken all of his pain, every negative memory and emotion. He hadn't just given Thomas relief from physical agony; he'd given him peace. Permanently.

And it was sickening. Because everyone needed a little discontent in their lives. It was what gave people ambition, made them strive for new things – the feeling that 'okay, things are nice now, but they could be better'.

He'd left Thomas completely content, completely at peace, no matter what happened around him or even to him. And it was the most horrifying thing John had ever seen.

Thomas' family wanted to meet him. John declined. He was invalided home. John didn't fight it.

He'd always known he had to be careful with his empathy. But he'd never dreamed he was capable of something so hideous. He'd never thought he could reach inside someone and take away everything that motivated them, everything that made them who they were, and leave them an empty, smiling shell that wouldn't even resent him because they'd lost the capacity for resentment.

John didn't think it was a coincidence that the day after he saw Thomas, he started limping. With the leg that Thomas was missing.

After all, he'd always known he was unusual, but that was the first time he'd considered himself a monster.

He never made any kind of effort to connect with people after his discharge, not even Harry. He locked himself in his flat and stared at his gun and contemplated eating a bullet.

Because he was monster. And at the end of the story, the monsters didn't get happy endings.

They died.

xx

John was still shaky when they got back to the flat. Facing death was one thing – been there, done that – but the memory of that awful, sucking emptiness made him feel nauseous every time he thought about it. He hadn't even tried to push anything onto the snipers, afraid Moriarty would just suck it all away.

But he wouldn't take this lying down, either. John might have been willing to accept his own demise as punishment for Thomas and insurance he would never do such a thing again, but if Sherlock's death came with it? That was a line he refused to cross.

For a while – a long while, really – John had considered his empathy useless. It didn't identify Kemp, after all, and his healing of Thomas had been disastrous. Still, he couldn't help but remember that his empathy had made him wary of Moriarty when even Sherlock had dismissed him. His empathy had allowed him to delay Sherlock taking the pill, and maybe it had some monstrous aspects, but maybe – now that he knew he had to be careful, now that he knew the horrific things it could do – maybe if he was careful, he could make it a force for good. Like he had back before…Thomas.

Maybe his empathy could be useful again, instead of a painful, misery-inducing burden.

"Sherlock…" he began, slowly and carefully, making tea just to give himself something to do. "Hypothetically, say that-"

The sudden crash of anger and fear from Sherlock was like the detonation of a grenade. "What did he do?"

John blinked, trying to reorient himself after the sudden emotional backlash. "Sorry, what?"

Sherlock was standing in the entrance to the kitchen, his eyes dark and his emotions wild. "You're uncomfortable, your leg is giving you trouble, and while you usually value eye contact when speaking you've yet to meet my eyes since we entered the house. All indications are that you are wrestling with something unpleasant that you want me to know, but fear my reaction to, so I will repeat – what did he do?"

Sometimes, John thought it was almost funny, how Sherlock could see almost every detail of a situation but miss the one that explained it all. He was uncomfortable, and his leg was giving him trouble (Moriarty's emptiness was of a different flavour than Thomas', but it was still a disturbing reminder of his sins), and he was trying to discuss something unpleasant …but Sherlock had assumed it was linked to Moriarty, that something had happened to John before he'd arrived at the pool.

Which John supposed wasn't an unreasonable assumption to make, considering.

"Nothing," he said quickly. Then pulled a face and amended, "Well, apart from the bomb and the snipers, but you were there for that part. And before that, he just did a lot of strutting around and talking, though he did slap me once."

Sherlock's fear dimmed like a failing bulb, but the smoky anger was still present, though it was tempered with treacle-thick confusion. "He slapped you?"

John nodded. "Pretty rubbish slap, actually – barely even hurt. Harry gave me worse when we were kids."

Sherlock snorted, shimmering amusement and cottony relief softening the edges of his fury as the corners of his mouth quirked, and John grinned.

Then he looked down, forcing himself to concentrate on dipping his tea bag into the hot water. "Hypothetically-"

"Oh, must we have the charade?" Sherlock sighed. "I know you're referring to yourself, you know you're referring to yourself, can't we discard the-"

"No," John said firmly, interrupting whatever tangential rant Sherlock had been about to launch into. "And yes, we must have the charade – it helps me, so you can just put up with it."

He took Sherlock's silence – and the vague throb of curiosity and something that felt disturbingly close to lumpy-armchair sympathy and minty worry – as consent.

"Hypothetically," he repeated, just to hear Sherlock scoff. "If someone had been badly injured, and his doctor performed a risky, never-before-tested medical procedure to try to save him, and it killed him, would you say that doctor had committed a crime?"

He thought framing it as a possible crime would get a more honest response from Sherlock.

"Would they have died anyway?" came Sherlock's voice from behind him.

John thought of the mangled mass of thigh – bone and gristle exposed to open air, everything below the knee just gone, blown into pieces, the way blood had squirted from the femoral artery, the already-depleted supplies in his kit and how far away they were from the base – and nodded.

"Then I don't see the moral dilemma. Medical procedures sometimes go wrong, don't they?"

There was a note of reassurance in Sherlock's voice and in his emotions, and John realised that Sherlock was trying to comfort him. For a moment he almost laughed, wondering what the MET would think of the self-proclaimed sociopath now, trying to console John about losing a friend (and possibly something more) without the slightest trace of mockery.

But the thing was, it worked. Somehow those words allowed John to relax, allowed him to finally shelve the guilt he'd been carrying for months. It was still there, of course, but it didn't weigh as heavily on him. The thought had been growing for weeks, the thought that perhaps he'd been too vicious with himself, that all doctors lost patients and made mistakes, and the point wasn't that they were perfect but that they were trying…but he'd needed someone else to say it.

If it had been an ordinary, non-empathic medical procedure, he'd have been reviewed by a board. Instead, he was being reviewed by Sherlock.

And John tried not to think about the fact that Sherlock's tacit approval and absolution made him feel much better than any review board he'd ever seen.

He'd already made up his mind about the bond, but he couldn't deny that made his decision seem that much more justifiable.

xx