For Drawnlock on tumblr, who drew me an amazing picture of Sherlock as Phineas and Ferb (I asked for it, my mind is on crack sometimes) anyway, here:

Sherlock Holmes is by nobody's description a 'sensitive' man, he is not one to empathise - grief, heartache, loss - boring, next case. He does not do 'apologetic' and only does 'polite' if the situation calls for it. No. Sherlock Holmes has never been a sensitive man in that sense of the word.

In the literal, strictly sensory sense of the word, Sherlock is in actual fact, incredibly sensitive. He can detective a 0.7% blue shift in a photograph with the naked eye, can identify a woman by her perfume and proceed to list all the ingredients of the scent and to what extent ("13% sandalwood with a few drops of rose extract for good measure... the cheap kind not the decent stuff") and can sift through the myriad of everyday sounds in a crowded room to pinpoint the location of the murderer's ringing cell phone. Yes. In a strictly sensory sense of the word, Sherlock Holmes is incredibly sensitive.

It was his dual insensitivity/sensitivity combo that lead him to discovering John's nightmares early on in their friendship, but not really caring enough to do anything about them. In fact, within a week of living together, they became an annoyance. Sherlock did not sleep regular hours, so was often downstairs in the kitchen or living room long after John went to bed for the night (sensible, boring). His sensitive ears pricked up, hearing the familiar creaks and groans of a mattress being thrashed about upon, the groaning springs irritating Sherlock to no end.

It was not surprising, easy enough to work out (though impossible then for him to understand) that a man just home from a bloody war was still haunted by it in his sleep. Obvious really, tedious. A few more drops of hydrogen peroxide to his ongoing experiment and then came a haggered cry from above:
"DOLLY!" Curious. Very curious. Sherlock scanned his databases, trying to surmise why his new flatmate would be crying out for a children's toy during a nightmare that ought to be about the war. Nothing, perhaps (it had been known to happen, rarely) he had misheard? 'Trolly', 'Folly', 'Golly'? No. Nothing that seemed to fit. It was definitely curious, but Sherlock was busy, he pushed the thought from his mind and continued on with his chemistry experiment.

A few weeks later it happened again, Sherlock was unsurprised, he had been living with John a few months by that point - had learned to predict John's behaviour to the letter. Nightmares usually followed particularly dangerous cases (Sherlock mused that this was perhaps, in a way, his fault. John was a grown man though, capable of making his own decisions, he chose to come along, Sherlock did not force him). The case had just wound down and Sherlock had no ongoing experiments, so when he heard thrashing, the gasping, and the cry once more of:
"DOLLY!" His curiosity peaked. He had not misheard the first time, John was not saying 'Holly' or 'Molly' or 'Polly', no, he was crying out for someone in his dreams. It was not an aroused cry of the man in throes of passion, it was a fearful wail of a man in terror, the scream of a man who feared for his life.

He booted up John's laptop and ran several searches in multiple tabs. It didn't take long. The noises from upstairs had ceased, indicating John had either woken up from his time in his torturous limbo, or had fallen into a different stage of the sleep cycle. Sherlock found what he was looking for quickly.
"Chris Dalton, affectionately known as 'Dolly' to his friends and family, 5th Northumberland Fusiliers 1990-2010." A soldier, barely an adult. According to his obituary he had died in service in Afghanistan. Mystery solved. Rather pedestrian. John evidently had some sort of a guilt-complex over the young man's death (had he witnessed it? been a part of it? Attempted (and failed) to save him?). It was war, people died. Sherlock was neither shocked by this news or particularly affected. He quite liked John, he was interesting as far as ordinary people went - but that was as far as it went. John would grow bored of tolerating him and his eccentric behaviour eventually (sooner rather than later, according to past experiences) and he would leave. Sherlock would not involve himself in John's tangled past, even if it meant ignoring his present. He did not mention Dolly to John, ever.

The first time John's night terrors bothered Sherlock (on an emotional level, on a sensory leevel they had irked him since day one) came after 'The Great Game' (as John would come to dub it on his godforsaken nonsense blog). They had nearly been blown up, John had been wrapped up in a live bomb that would have blown them all sky high - it was a prime night for a visit from his old demons. Truth be told even Sherlock had been a little shaken, John had taken himself to bed without a word, and Sherlock had made himself a mug of tea (he much preferred when John made him tea), settling onto the sofa.

It started the way it always did, creaking mattress, groaning springs, the occasional thud as John knocked something over in his nocturnal distress. Sherlock checked his watch, John's nightmares were predictable - usually. A gasp, a frightened cry from above and then (Sherlock waited for it, for Dolly's name to sound) instead a scream
"SHERLOCK!" Sherlock's blood ran cold, then came the silence (on closer inspection, panting, John had woken up). The scream of a man who was watching a good friend die, he'd heard it before, never his own name. Nobody had ever cared enough, nobody had ever been there, in his dangerous web. Nobody until John.

That bothered him. Immensely. Perhaps a statement of their friendship, someone in Sherlock's life who maybe would not flee, who maybe would stay. Maybe. Sherlock shook the sentimentality from his brain. John's nightmares were becoming a bother to them both, so Sherlock would have to do something about them.

He had experienced night terrors briefly, in his extreme youth - before his logical mind had kicked in and told him it was all in his head, nothing to fear. He had experienced them again in his addict days, drugs lowering his defences, opening his mind to demons unfought. It was not his department really, he had no research to back it up, but he did know one thing that soothed him during and after. Mycroft had played the piano, and as much as Sherlock was loathed to admit it, the music had calmed him. Perhaps John was not so cultured as to appreciate the relaxant that was classical music? It may make him more irritable - cause him to lose more sleep?

It was worth a shot.

Sherlock carefully opened his violin case, he did not want to play so loud as to wake Mrs Hudson below (that is, if John's crashing about had not disturbed her already) so instead, he wandered to the foot of the stairs, staring up into the blackness above, broken by a slit of yellow from under John's bedroom door (he had turned the bedside lamp on) and began to play. Initially he played to calm John, in the hopes that above him, John would hear the notes as they sweetly climbed the staircase and slipped into his room, he played to ease his friend's troubled mind, he played each note for John and John alone - he had forgotten how effective music was at calming himself. He played as he always played, his heart (if he had one, Moriarty had said he did, John thought he did, Sherlock was undecided) in every swift motion of his bow against the taut strings, emotions he had never expressed wound into the tune. It was therapeutic for him, the night had had more of an effect on Sherlock than he had realised until he had picked up the violin.

He played for nearly an hour, the melodies of the greats one after another, he listened for sounds above between each note and heard none, silence. The light was still on but Sherlock played on, until he was convinced John was fast asleep, untroubled. Sherlock had never had a friend before, it was a decidedly odd feeling, as he lay his violin back in its elaborate casing, he would even go as far as to say he cared (only a little) for John's mental state. After all, it would do him no good to have a haunted assistant.

John did not say a word the next morning, about his nightmares (he never did) or about Sherlock's playing. An unspoken agreement perhaps? A code honoured between men? Sherlock was grateful for John's silence on the subject to be honest - it had not been an entirely selfless deed and Sherlock did not want John to mistakenly think him kinder than he was. Sherlock received no confirmation that John had even acknowledged his playing until the next dangerous case, the next night John was due a nightmare. Interesting - even John knew when he was prone to nightmares, yet instead of avoiding the dangers that triggered them, he actively persued it despite the unpleasant side effects.

Either way, that night (several weeks after the Game) he left his bedroom door ajar. John was a proud man, far too proud to ask for help with such a trivial matter, but Sherlock (to his slight surprise) understood (he did not often understand minor behavioural adjustments) that John's leaving his door open was a silent plea - last time the music had soothed him and he longed to hear it again. Decision made then, Sherlock allowed John to settle in his room for the night, the noises of him clattering about, brushing his teeth and getting into bed made louder by the fact they weren't hindered by a closed door. Sherlock waited until there was silence and picked up his violin to pre-empt the inevitable bad dream.

Soothing, calming, relaxing. Not enough. The tune interupted (Sherlock only paused for a moment) by cries of abuse from the mattress above, a frightened gasping. The nightmare had begun. Sherlock played on (slightly annoyed at the momentary pause - it threw off his rhythym, John in his distressed state was a lousy audience). He lowered the tempo, each stroke of the bow slower and more deliberate. The panting - John was running in his dreams by the sound of it, running to someone? Away from something? Hard to tell. Not Sherlock's place to know - he continued his gentle soothing lullaby, only stopping very briefly when he heard
"SHERLOCK!" From above. Still terrified. Pre-empting the dream had not worked. Sherlock did not mind, he hadn't seen off the dream last time, that was not what John wanted. He didn't want to be relieved of his nightmares (not via violin at any rate), just put at ease afterwards. He wanted comfort, reassurance. Sherlock's hauntingly beautiful melodies reminded John that his friend was alive, well, and being a sodding nuisance at 3am. Sherlock was not a doctor, he could not cure John of his ailment - but he could make it better afterwards and that in itself was healing.

And so, swaying slightly, week after week, Sherlock took the role of sandman. Sherlock had his danger nights, though they were few and far between these days, and always John ransacked his belongings, spied on him, looked out for him. So Sherlock did the same, in his own way, on John's danger nights he would dutifully (and it was a duty, really, Sherlock owed the man as much - nobody else had put up with him for long, nobody else had considered him a friend) strike up a tune on his trusty violin and erase the trauma with a few sweet notes. A song for their ears only. It was as intimate an act as Sherlock would ever perform, so he played with care, entrusted his soul to the violin, and the violin to John for a few hours a month when he needed it.

Sherlock still played for himself, when he needed to think, when he needed to calm himself, when he needed a cigarette - John never complained. He came home once, after a row with a girlfriend (Sherlock knew John thought he was just being an arse when he couldn't identify which girlfriend was which at the Christmas party some weeks earlier, but Sherlock honestly did not care enough to remember who was who - it all cluttered the mind palace too much. He cared about John, yes, but that did not extend to his innumerable partners). He was frazzled, distressed, worked up. Sitting himself in the armchair by the fire, drumming his fingers on the chair arm angrily. Sherlock observed him the way he would anyone else, he noticed the creased brow, the tense shoulders, the irate tapping of his digits. Yes, John was most certainly stressed. Sherlock frowned, he didn't really feel in the mood for playing - the other option however was allowing John to watch mindless rubbish on the television and Sherlock simply would not stand for that.

Sherlock carefully removed his precious violin from the case, and idly wondered when it had become John's as much as his. John did not play, but the object now held some sort of sentimental value to the older man, as evidence by his eyes following Sherlock's hands as he picked it up. Sherlock nearly always faced the window when he played, but tonight, for the first time in many years, he had an audience. He looked at John as he struck the first few notes, the effect was instantaneous, a few chords and John's shoulders sagged, his brow uncreased and his fingers unfurled and stilled, by the end of the first line John was calmed.

'Is this what happens on the nights he has bad dreams?' Sherlock wondered to himself, did John wake up, panicked and frightened, hear the soothing music and become soft, pliant and relaxed? Sherlock carried on, watching John's eyelids flutter closed as he listened intently, swaying his head very slightly in time to the tune. It was somewhat hypnotic, Sherlock had no idea John was so affected by his playing and he almost immediately regretted picking such a short piece. By the end of the song, despite its length, John was utterly blissed out, eyes closed and a small smile curling at the corners of his mouth. Sherlock hung onto the last notes for a few moments longer than necessary before lowering his bow.

John was in no hurry, he opened his eyes when he was ready, still smiling.
"Beautiful." He said simply, and Sherlock felt the massive swell of pride in his chest that always came with a compliment from John - Sherlock had to admit, sometimes he only did 'good' things because it caused John to stroke his massive ego, Sherlock was as narcissistic as they come, an egomaniac most definitely - but this was different. The music had become something 'beautiful', something to be shared in times of need. Sherlock nodded his head.
"Go to bed John, you'll feel better in the morning." He instructed, not putting down the violin. John sighed and rose from his chair.
"Yeah, probably will. Goodnight Sherlock and..." John hesitated, unsure how to phrase 'thank you for the music' without sounding like a cheesy pop reference. Sherlock quirked an eyebrow, they were going to discuss this? He didn't see any need to discuss it, perhaps in the beginning - when his reasons for playing hadn't been entirely altruistic (it shut John up, that was all), perhaps then it had needed discussing, perhaps he had needed chastising for it. Not now, now that it was what it was, a friend helping a friend, with no bones about it. It did not need to be discussed now.

"Thanks, for being a mate." John settled on. Sherlock cleared his throat awkwardly, comradery among men was not high on the large list of subjects he was knowledgable about. He twirled his bow between his long fingers before pointing it at the staircase.
"Goodnight John." He offered, and John took the hint, heading up to bed. He had only reached the seventh step when Sherlock struck up another tune, John smiled to himself and left his bedroom door open slightly.

A/n: Done. This is for drawnlock who requested some 'platonic Johnlock'... I hope this was platonic enough for you!