AN: Huge gigantic thank you to Bittersweet Fable for posting the idea/prompt for this fic on a forum board several years ago. This afternoon I happened to be looking for prompts and found that one and, at least partly thanks to the incredibly detailed structure of the prompt, discovered that I couldn't help but start writing it. It's not completely what you described, I know, but the essence is here, I think! I hope you like it-all of you! (I'm still working on "The Truth", I promise: I'm just...stuck!)

The night was—well, it wasn't warm, exactly, but the brisk bite to the air was welcome and familiar, especially to John's heated face. It wasn't as though a chip-and-PIN machine should be so difficult to operate. He was a doctor. He could stitch a broken and bloody soldier back together and keep his body ticking throughout a battle. His "success-to-failure" ratio was at least average, and the human body was certainly more complicated than a machine which displayed instructions on a tiny little bloody screen. He drew in a deep breath and released it, then adjusted the multiple bags of groceries that now weighed him down. There were no cabs to be found, of course—it seemed that, without Sherlock's supernatural ability to summon them from thin air, John would be forced to walk all the way back to the flat. Well, it was that or the tube.

A bit of a snort, then, as John imagined himself trying to fight his way onto a train lugging all these bags, and then trying to find a seat or even a pole to keep himself upright, and then trying to defend his loot against the band of thugs which would inexplicably but inevitably begin to surround him. He fought back the giggles that rose in his throat as the scenario grew more and more ridiculous, finally culminating in one particularly disgruntled-looking delinquent plucking the tin of biscuits (Sherlock's favorite—at least he could get him to eat something) out of the topmost bag and dashing out the doors as the train rolled to a stop.

"God, I need more sleep," he muttered to himself, and wished that he had a free hand with which to rub his eyes. In the army, he'd discovered that it was in his best interest not to count the hours he was forced to go without sleep, and living with Sherlock was absolutely reinforcing that knowledge. He was probably going on close to forty-six hours at this point, not counting the worthless little catnaps he managed to grab in cabs and on breaks from the surgery. Alright, John, just a few more blocks and you'll be home. With any luck, Sherlock will be distracted and you can lock yourself in your bedroom and sleep for the rest of the night. Maybe even the rest of your life. Realistically, John knew that such expectations were highly improbable, but maybe he'd get an hour or two, or six, if he was lucky.

Maybe if he had been more rested, or less weighed-down, or more observant like the great Sherlock Holmes, he might have noticed more in time. As it stood, the only thing that made its way through his sleep-befuddled brain was the blurry form of a cream-colored cat dashing across the street and right across his path. John stopped in his tracks, to keep from treading on the poor thing's paws or tail, and it was at that moment that he heard first the angry squeal of brakes on damp road and then the sickening thud. He didn't think, didn't look at the cat, didn't worry about traffic—John let the groceries fall to the ground and raced into the street. The driver was getting out of the cab, and his words only dimly registered in some small part of John's brain—"Christ, I couldn't stop, she just ran out into the bloody road. Is she okay?" John bit out some order in the tone of voice he seldom used outside of the army—"call 999" or maybe "get an ambulance" or, quite possibly, something closer to "shut the fuck up and get away from here".

She was a little girl, shattered and bleeding out all over the road. There were no hysterical mothers screaming and running to her side, no fathers thundering through the crowd which by now had begun to gather. Even as John worked quickly, checking for a pulse (thready), checking for pupil response (one blown, reaction sluggish), ordering her not to move ("It's alright, love, I'm a doctor, I'm going to save you but you've got to be still for me, okay?"), he was picking up on her appearance. Her hair was long and fell in tangles around her face, soaking up the halo of blood which surrounded her. Her clothes were obviously hand-me-downs or handouts from a charity, her nails and hands dirty, shoes worn-out and holey. Homeless, most likely, or at least very, very poor, and John couldn't decide whether to hope that she was an orphan or not.

She only spoke once, in a pained, rasping little voice as John prodded her abdomen (massive internal bleeding, it wasn't even a question): "Maestro. Where's Maestro? My cat..." She trailed off, interrupted by a dry, hacking cough that made her whimper. Pneumothorax, there was no question. John glanced up at her face (fuck, she couldn't have been older than seven), and noted with growing alarm that her lips were already turning blue. This was bad. This was...bad.

Despite himself, John paused for a moment and looked at the sidewalk where he'd been standing just moments before. In the ring of light cast by the streetlamp onto his discarded groceries, the cat which had froze him sat staring at the scene. He didn't look regal, as John found most cats appeared, or even mysterious or arrogant, but almost...concerned. "He's just over there, waiting for you. What's your name?" It wasn't advisable for her to be speaking with a collapsed lung, but he didn't want her fading out on him, either. She coughed again, just as painfully, and blood trickled from the corner of her mouth.

"Want to see..." she managed, and if it weren't for John's quick thinking and his hand stabilising her face, she would have turned her head to look. "Please..." She was whining now, a startlingly childish sound, but certainly that was to be expected. John bit out an order for someone to bring the cat to them (hygiene protocols be damned), and presently someone was placing the fluffy creature in reach of the little girl. Where was that bloody ambulance? One dirty little hand, scraped up and bloody, fisted in the cat's fur, and tears squeezed out the corners of her eyes. "Matilda." Another cough, another trickle of blood. This was decidedly Not Good. "Like the book." There was another childish whimper, and she fell silent. The cat lay like a sphinx under her desperate hand, watching John with icy blue eyes.

John didn't work with children. He worked with soldiers—granted, many of the men he'd patched up or lost were still children themselves, but at least they'd volunteered for it, signed up to be shipped off and blown up in the middle of the desert. He'd done a stint in emergency while he was training, sure, but had been lucky enough to get mainly drunks and men who didn't know how to handle power tools. The few children that he did take on were easy ones—broken legs from soccer practice or things like that. The broken children, children like Matilda, he at least hadn't had to handle on his own. There had been a team. Right now it was just him and an ever-growing throng of onlookers.

He didn't have anything to save her with. If he'd had a medical kit, he could try to relieve the pressure in her chest, could stabilise her neck, could at least cover her with a blanket to try to stave off shock. He could feel the audience watching, silently judging him for not doing more. This wasn't the films, wasn't television. He didn't conveniently have anything handy in his groceries, even—just tea and milk and biscuits and other food items that he might not have hesitated to give to a little girl left alone and dirty in the streets, but which wouldn't do a bloody bit of good right now. He shrugged out of his jacket and tucked it around her. Better than nothing.

The faint cries of an ambulance began to sound in the distance, and relief flooded through John even as the girl's breaths became more ragged. Just as John was weighing the risks of aggravating a neck or back injury by turning her onto her side with the benefits of relieving the pressure on her lungs, she stopped breathing altogether. No. This wasn't going to happen. He began CPR, doing his best to keep her airway open without jolting her spine around, though at this point it was a case of the lesser of two evils. It was bad enough for a seven-year-old to be paralysed, but it was much much worse for that seven-year-old to be dead.

John's world shrank to the glaring light cast by the headlights of the cab and the frantic breaths-compressions-check-breaths-compressions-check pattern he hoped would keep her living. He didn't know how much time was passing, and the strong pair of hands under his arms, pulling him away from the girl and then out of the street didn't register until he was being shaken. He looked over at the site just in time to see the technicians shaking their heads and rocking back onto their heels. He was dimly aware of some questions being answered of him, managed to answer them with short, perfunctory information, and began walking numbly away when he was dismissed. Someone called after him, something about "these bags" or "this cat", but he didn't hear them fully, and didn't care at all.

Sherlock was in the middle of an article about gene splicing (rubbish; the author clearly had no idea what he was talking about) when he heard John enter the flat. He could tell by the ease with which the other man had managed to open the door that he was not carrying much in the way of grocery bags.

"Had another row with the machine?" He was amused. It was strange that the shop seemed to hold such a fiery grudge against the other man: it seemed that he was returning home flustered and angry almost once a month lately. When he heard nothing in response—no scoff, no frustrated sigh, no snarky reply or demand that he go buy groceries once in a while—he looked up. John was pale, paler even than the nights when he joined him in the sitting room seeking refuge from his nightmares. The knees of his trousers were wet and muddy, and his shirt was spotted with dark red spots that looked remarkably like blood. He wasn't wearing a jacket. Sherlock dropped the magazine and rose to his feet, taking several steps toward his flatmate.

"Where are the groceries, John?" He was trying to keep his voice low, soothing. John looked at his hands (bloody) and then finally met Sherlock's questioning gaze. His eyes were wide but blank, uncomprehending. Before Sherlock could say another word, the shorter man was pushing past him, rushing to the bathroom. Sherlock waited all of about three seconds before following him.

John was washing—no, scrubbing his hands under water that gradually began to send wisps of steam into the air. Sherlock watched silently, unsure of exactly what to do, until all of the blood had been washed down the drain and John's hands began to burn a dangerous shade of red. Finally, he had no other choice but to grab the man by his wrists and pull them free from the scalding water. He fought valiantly, but it had been quite a while since the soldier had needed to have brute physical strength, and Sherlock managed to overpower him.

"There's blood," John was repeating as he struggled. "I don't want her blood...Sherlock, there's blood, let me go!"

"Your hands are clean, John," Sherlock said, loudly and firmly, hoping to break through whatever psychotic break John was currently experiencing. "Look at them. They're clean. There is no blood on your hands."

John met his gaze again, and, slowly, the life began to return to his eyes. Sherlock's relief was short-lived, as immediately afterwards, John broke out of his grasp and pushed past him again, mumbling something about bed before stomping up the stairs to his bedroom.

There was a cat, and it wouldn't stop staring at him. It blamed him for something. As John watched in horror, it disappeared from the windowsill, only to reappear at the foot of his bed. It crept along the length of his body, finally stretching out across his face, his mouth. He fought in vain, trying to claw it away from him, trying to breathe, but it wouldn't move. Just as he thought he was going to die, the cat disappeared and he was on his knees in the street again.

The girl was there, Matilda, still broken and bloodied but also, at least, still breathing. This time, John acted quicker, turning her onto her side to keep the fluid and pressure from further damaging her lungs. She was crying, full-body sobs that wracked through her and distressed John. She was going to hurt herself worse if she didn't stop crying. Nothing John said could console her, though he cycled through his soothing, calming voice to his authoritative, commanding voice to his confident, knowledgeable doctor's voice. She just kept shivering, wailing.

An explosion from behind. John threw himself carefully over the girl to shield her from falling debris, and when he finally rose to his knees again, she was no longer breathing. The crowd surrounding him began pressing closer, close enough for him to see the malice and hatred growing in their snarling faces. Someone shouted something at him—Farsi or Dari, he wasn't completely sure—and they all rushed in towards him. He was being crushed under their feet, but groped through the crowd to find the girl. If he could drag her out of the mess, he told himself, he could still save her somehow. His fingers closed around something and he began to fight his way out from under the feet and claws of the people. It was only when he was leaning against the side of a building, hopefully far enough from danger, that he looked down at what he was carrying. It was the cat, teeth bared, claws extended, and hissing like a demon. He dropped it with a shout and tried to run, but it chased him down the alley, seemingly growing larger as the distance between them. It was snapping at his heels as he ran, hissing steam and blood down his back. It was getting closer, he knew, and when it finally caught him, it would devour him and spit him out into the street next to the girl he'd failed.

Sherlock hovered in John's doorway, noting the strangeness of the situation. He was no stranger to John's nightmares. Sometimes he would hear him tossing and turning angrily in his sleep, and occasionally even the telltale thump when the man, struggling against the restraints of his sheets, fell out of bed and onto the floor. He knew that John usually roused himself from such dreams and made his way downstairs. He would make tea and then sit in his chair, watching late-night-early-morning telly until the sun rose or he fell back into a fitful and uncomfortable sleep. No, the nightmare was not the strange part about the night.

The strange part was that John was not waking himself. This nightmare had gone on far longer than they usually did, and John was much more vocal than usual, which was what had summoned Sherlock to the doorway. He stood in the frame of light from the hall, casting a shadow across John's bed and wondering whether he should wake him.

The research conflicted as to whether it was harmful to wake someone from the throes of nightmares. It was risky, in any case. If he startled John too badly in this state, he could quite possibly go into cardiac arrest. It was clear that his heart rate was already soaring, his blood pressure dangerously high. At the same time, it was that very state which could also cause damage, if Sherlock let it go on for too long. Surely it was better to allow John to come back to consciousness, to the real world where there were no enemy soldiers trying to blow him up. John didn't talk about his dreams, of course, but Sherlock figured they were likely about Afghanistan.

(He didn't dare bring up the topic of PTSD to the man.)

Decision made, Sherlock moved resolutely to the side of John's bed. He knew he was risking a rather painful punch to the face or other extremities, but it was, overall, a much smaller risk than that of losing John to his subconscious. After a moment's hesitation, he finally reached down and took a firm hold of John's shoulder, shaking his roughly. Judging by the groans of fear the man was making, there was not much time for tenderness.

"John," he bit out. His voice wasn't panicked (Sherlock Holmes? Panic? Not likely.) but it was sharp and commanding in the stillness of the bedroom. "John, wake up right this minute." Another shake, and Sherlock was jerking away from the fist that came flying towards him. He said nothing for a moment or two—just long enough for both men to regain a bit of composure—and then cleared his throat. "You were dreaming."

"Wha—Right." John's voice was sleep-frogged. He sat up slowly and kicked the tangled sheets to the floor. "Was I shouting? Sorry."

"What happened tonight?" Normally Sherlock was not the one to pry (indeed, he found that in many cases, the less that other people volunteered to him about their problems, the better), but this was John, and it was clear that he had been extremely rattled when he came home. "Whose blood was that?" He considered trying a joke, asking if he needed to call Mycroft in for damage control, but sensed that this was not the time. He was getting better at that. "And please do not insult my intelligence by telling me that it was "nothing" because, honestly..."

John drew in a breath and released it in a heavy sigh, dropping his head into his hands. "I failed her, Sherlock," he mumbled, and only the quiet that shrouded the two of them in the room allowed Sherlock to catch the words. He stood frozen in place. Despite all the good influence that John had brought to Sherlock's life, he was ill-prepared to deal with situations like this. He took a guess.

"Who?"

John looked up, now, and in the light pouring in from the hallway, Sherlock could see the tears glittering in his eyes. This nearly brought him to his knees. John Watson the soldier rarely cried, and when he did, it was not because of a nightmare. Sherlock took a step forward and sank down onto the bed next to the other man. John immediately reached out to wrap his hands around one of Sherlock's, holding tightly like he was afraid he would disappear into the night. "There was a girl..."

It took nearly an hour, but Sherlock was able to piece together the story. Eventually John fell silent, save for a softly-whispered "Couldn't save her, couldn't save anyone." John was no longer sitting in his bed in 221b Baker Street, but perhaps on a cot somewhere in Afghanistan, watching with blank horror as each of the men he had failed to save died before him, one after another. Sherlock gently removed his hand from his friend's and rose to his feet.

"Where are you going?" John's voice was small, panicked in the darkness.

"I'm going to get you some tea," he replied. In a better situation, John might have snorted at him or made some crack about that swill not being tea, or...really, anything, but for several long moments he just looked at him with wide eyes. Sherlock shifted his weight from one foot to the other. "Or...would you prefer I just...stay here?"

The nod was almost imperceptible, but Sherlock didn't miss much. Tea forgotten, he gently pressed John back to the mattress and stooped to pick up the once-abandoned sheets from the floor. Without giving it much thought (because if he did, he would find himself slinking like a coward from the room), he slid into the bed on the other side of John and covered them both with the sheets. At first, John remained motionless on his side, but as his desire for comfort began to outweigh whatever discomfort having Sherlock in his bed made him feel, he turned to Sherlock and, in one swift motion, buried his face in his shoulder with his arm slung around his waist. John's shoulders rose and fell, and between the combination of his erratic breathing and the drops of hot moisture that were beginning to soak through his shirt, Sherlock realized that he was crying again. Though momentarily taken aback, Sherlock quickly manoeuvred to slide his arm under John's head. Lithe fingers played in the blond hair, finding it softer than he'd expected.

"You couldn't have saved her," Sherlock finally said, keeping his voice low. The room felt...sacred, not that he usually went in for such things, but he still didn't want to disturb...anything. He turned his head so that his lips were pressed against the side of John's head. It felt of the utmost importance that John hear this, that he understand it. "The injuries that you described, it sounds like the cab was speeding by quite a lot. There was too much internal bleeding, too much damage. You wouldn't have been able to do much for her even in a fully-supplied hospital room, do you understand that?" His voice grew rough. He so rarely gave in to sentiment, but tonight he had no other choice. It wasn't for him; it was for his friend. "You did not fail her. You did not fail anyone. You have only ever done your best, John, and that is all that anyone could ever expect from you."

There was silence from the other man, but that, at least, meant that he was no longer crying. After a moment or two, there came a rather undignified sniffle from the area of Sherlock's shoulder, and then John moved to press his face into his neck instead. "Thank you, Sherlock." The words were a warm whisper against pale skin.

Sherlock paused, unsure whether to say "You're welcome" or "There's no need to thank me: what I said was completely true" or perhaps some other option, and while he was deciding, he realized that John's breath was slowing, evening out. He was falling asleep. Nothing, therefore, needed to be said. Well, that was easy. Sherlock remained awake and motionless throughout the rest of the night, unwilling both to shift and risk waking John and drift off to sleep and leave him alone with the nightmares. He needn't have worried, really—John slept peacefully in his friend's embrace, and the nightmares stayed far away.