Warnings (For Entire Piece): Gore, language, scenes of a sexual nature, mentions of child abuse and torture (in the past), demons, magic, possession, elements of dubious consent in some areas.

A/N: This piece was written for Trilliv as part of the johnlockchallenges gift exchange. I got a five word prompt: "Faust: Sherlock sells his soul." To say I ran with it is an embarrassing understatement. This is part one of four, next update is scheduled for December 8th. Thank you, Trilliv, for a very awesome prompt!

As always, you can follow me at beautifulfic DOT Tumblr DOT com for previews, exclusives etc.
Much love,
B xxx


The Stars Move Still: Part One - Conjuration

"The stars move still, time runs, the clock will strike,

The devil will come, and Faustus must be damned."

- Christopher Marlowe 'The Tragical History of Doctor Faustus'


Power saturated the air, mixing with the rich, metallic scent of blood. The walls were covered in it: white paint stained in shades of claret. However, the carnage was far from the most striking detail of the little bedsit in Bethnal Green.

'Whoever drew this was careless. Either that or a complete amateur.' Sherlock dipped his finger into the wobbling chalk line of the circle's edge. It was poorly constructed, barely enclosing the space within. That was how the demon had been able to take far more than its summoner wanted to offer. The ashen silhouette of a protective amulet lay near his foot, nothing but a husk. 'They went fishing for haddock and caught a shark.'

'Where is it now?' Lestrade asked. 'Am I looking at a loose monster in London, or can I wrap this case up as some daft bugger playing Faust and getting killed instead?'

'As if he knows that,' Donovan sneered, her lips curling as Sherlock met her gaze before returning his attention to the evidence.

'I don't understand why he's even here. A necromancer shouldn't be at a murder scene,' Anderson added with a sniff. 'For all you know he might be taking bits home with him.'

Sherlock closed his eyes, silently cursing the stupidity of people in general and the Forensics Lead in particular. 'Even if I were a necromancer, there's not much I could do with half an ear and a thin patina of blood.' He cast Anderson a dark look. 'The grave-arts are about raising the dead, not working out what made them into corpses in the first place.' To Lestrade, he held out his hand, palm up. 'I can tell you where your demon is, but I'll need your lighter.'

A ripple of unease stirred the air. Sherlock felt it as surely as if someone had opened a window, letting in a breeze that tickled those of his senses which were attuned beyond the standard fare. It was nothing ominous: mere human uncertainty. They knew what he was, but few of those from the Yard had seen him do any kind of magic. They all had the ability, to some extent or other, but there was a big difference between a basic practitioner and a masterful adept.

'Do we need to be in a –' Lestrade made a vague, protective motion with his left hand as he passed Sherlock the lighter, frowning when his only response was a faint sigh. 'If you drag something back here, Sherlock, I swear to God I'll lock you up and never let you go again. Level ten containment. Not even you could get out of that.'

It was not a meaningless warning, and Sherlock rolled his eyes, casting a deeper glance over Lestrade's team. They all glowed with their own powers and shields. Lestrade was bonfire bright while Anderson glittered, starlight weak, and Sally's intensity faltered somewhere between the two. Various others technicians added the rainbow colours of lesser spells to the mix: all safe and secure.

Then there was John.

When Sherlock had first seen him, he had been so surprised that he had almost lost his train of thought. Normally, power was symbolised as light to his higher-vision, but John was different. At any level of sight, he looked like a normal man, his flesh bare and exposed to the elemental powers that sluiced through London.

Fascinating.

Yet it had been Sherlock's other senses that had alerted him to the truth. John may not glow, but he radiated heat. Even now, more than a dozen paces apart, he could feel the glide of it like rough spun silk across his skin, blissful and tender. The lingering scent of dry air and sandalwood filled his nose, laced with the faintest acrid bite of gunpowder: the war dogging John's footsteps.

Sherlock had expected his magic to be out of the ordinary: particularly strong, perhaps – adept level at least, but John's abilities were limited to the basics. He was able to remove a curse and deal with most ailments, both paranormal and biological. He also had wards like reinforced concrete walls, but that was where his supernatural talents ended: practically mundane.

However, he made up for that normalcy in other ways.

When he had taken on a flatmate almost a year ago, Sherlock had expected to merely tolerate their presence. They would be a necessary intruder and nothing more. How wrong he had been. Within twenty-four hours, John had shot a man dead to save Sherlock's life. No questions, no expectations; he had simply pulled the trigger as if protecting Sherlock was the obvious choice.

From that moment, John had infiltrated his life, and surprisingly, Sherlock had not only allowed him to do so; he had welcomed it. Now, almost a year later, it was impossible to consider an existence where John was not there in the morning, grumpy and rumpled, or breathless after a chase, the pull of something hot coiling between them to be left regrettably unanswered. John was not a docile lamb following along in Sherlock's wake, but someone who engaged with him, challenging him even as he encouraged Sherlock to higher leaps of deduction.

With some effort, Sherlock focussed on the circle again, inwardly berating himself for his distraction. John had a habit of catching and holding his attention at the most inopportune moments. At first, he had thought it was simply because John was someone new to be categorised, understood, and then discarded, but even now that he knew John so well, he still found his thoughts drifting back to the man, captivated.

Breathing a sigh, he flicked his thumb over the lighter, letting the spark find ignition. Other mages would spend hours with magnificent circles, dripping candles – all the useless paraphernalia that so many people thought were essential. Perhaps for some they were a necessary crutch, but Sherlock had mastered some of the most complex spells known to man when he was eight. By the time he was twelve, he was making up his own, manipulating the fabric of the occult and creating new seams and folds for his own purposes: dangerous, but satisfying.

Magic stirred around him, and Sherlock urged his focus to shift down and in, picking up the lingering strands of conjuration and allowing his consciousness to ghost along them. A small part of him stayed in his physical form: a sentry in an empty house. If he strained his senses, he could still feel the floor beneath his feet and hear the soft, shocked noise one of Lestrade's men made. Vacancy often caused discomfort in the uninitiated. They did not like seeing the mostly-hollow shell of a human being that remained when a skilled mage went on the hunt.

The trail was fresh, which made his job easier. Truthfully, he could track a demon days after the circle to contact it had been activated, weeks, if the creature was powerful enough, but it was a challenge. Now, transit was brief and simple, like following the broad, straight sweep of Ermine Street from one end of the country to the other. Within seconds, the rushing torrent solidified around him, and the demon's realm came into view.

Sherlock's discorporate form was still hunkered in the same position as his physical one back in the real world, and he cautiously straightened up, every sense on high-alert. The generally held belief among the populace was that demons lived in worlds of fire and brimstone: unimaginative copies of Dante's notorious inferno. Everyone assumed that they were evil things, sent to steal the few, fragile virtues man called his own.

Wrong. As if the anything could be so black and white.

Demons were intelligent predators, and their worlds could be shaped to assume any form: already Sherlock was reading everything the environment had to tell him, and it was an interesting display. This place was dark and glossy, like polished jet or obsidian. The light played tricks on his eyes, but in the gloom it was possible to make out objects, and the fragrance of fresh blood and magic scented the air.

Like old gods long forgotten, demons embodied power. Human souls sustained them, and many had perished, unable to tempt or claim the food they needed. This one, however, was a success story. Even if it weren't for the transparent remnants of the unfortunate conjurer, bloodless and torn apart at Sherlock's feet, it was evident in the weight of the atmosphere. Ancient strength whispered promises in his ear. Temptation pulled on him like a bow line, seeking to draw him in, but he kept himself completely smooth, glassy and untouchable.

It was a challenge: take me if you can.

'Well,' a voice purred, drifting inwards from the walls to a single point of focus as a man stepped out of the shadows. 'Aren't you something special?'

As forms went, it was unremarkable, but Sherlock knew better than to pass judgement. Besides, a true observer would see the demon's strength in the cut of his suit, the sharpness of his smile and, more obviously, the bottomless black of eyes too dark to be anything like human: dank holes in the whiteness of the orb.

'I like to think so,' Sherlock replied, a hint of satisfaction scything through him as the demon raised an eyebrow in surprise.

'You can talk!' A laugh escaped the man's mouth, writhing like auditory worms through the dead air. 'Now that's new. He couldn't even breathe.' A neatly manicured hand flicked in the direction of the human remains. 'Most people who find me are too exhausted by the trip to do more than cry, but look at you!' The smile vanished, and the melodic, Irish brogue turned wanton and rough. 'Just look at you.'

The demon closed his eyes, breathing air in through his nose like someone savouring the scent of fine wine. Lashes fluttered in ecstasy, and a new smile twitched across the pallid elasticity of his face. 'You're practically seething with power. And your mind...' He tipped his head, observing Sherlock from an angle. 'I'd almost say you weren't human, except that I can taste your soul.'

A blink, and the demon was suddenly in his space, pressed so close that Sherlock could discern the heat of him dragging at his skin: clammy fingers sticking to the cold crystal of his wards. Yet the demon did not scrabble or snarl, instead he merely arched his spine, ignoring the burn of power as it began to stab and claw at the narrow distance between them.

It was not that the creature was resistant; Sherlock saw burns bloom and fade on its flesh with every passing second. Instead it was as if the pain was of no consequence to him, or perhaps just an adequate price to pay as he stared up into Sherlock's face, his gaze moving from side to side as if he were reading the lines from a book.

'Clever,' the demon murmured. 'You're putting thoughts to the forefront of your mind for me to see. Are any of them true?'

'Can't you tell?'

The creature's lips curved. An almost serpentine sway of his head gave something away of his nature: not human at all. 'I know you're not alone. There are others around you, weak, dull. Except...'

Something twitched across its face, taking the childish joy away with it as a frown creased his brow. 'Oh, you have a pet. He shines for you. Follows in your footsteps like a good little dog. Dodgy shoulder, crippled leg.' The demon grimaced. 'Better put it out of its misery.'

Magic slammed into Sherlock's shields as he met the assault head on, shoving the attack away from the path that would lead it back to John. Roars and crashes split the realm, and Sherlock felt a thrill as the demon's eyes widened.

'Oh,' he whispered, looking as if he had found something intriguing. 'More than a pet, then. Does he spread his legs for you? Whine into your pillows? Does he touch you?'

Fingers burned into the fragile skin over Sherlock's pulse, agonising points of contact as his wards creaked and groaned, not gone, not yet, but bowing under the onslaught. Stupid! Stupid! He had under-estimated the demon's strength, and now every nerve shrieked with the pain of his caress. It took all of his concentration to hold the monster at bay.

'Or could I be wrong? Not your lover, at least not yet,' the demon asked, breaking off and stepping away with a trembling, wistful sigh as Sherlock considered the option of retreat. 'You came looking, and now you already want to leave.' He pouted: a mockery of disappointment before a cruel smirk carved its line across his face. 'But I have what I want from you, Sherlock Holmes, and you'll come back.' Suit-clad shoulders twitched up towards his ears before relaxing again as he danced away, a puckish grin baring blunt, human teeth as he bit his lip in coy parody. 'I'll be waiting.'

Energy snapped around Sherlock's body, dragging him back to slam him painfully into the confines of his own flesh. Normally, the transition left him feeling constrained, chafed and captive within his body, but this time the sensation was drowned out by the thudding throb of a painful bruise at the hollow of his jaw: a lingering testament to that unwanted touch.

'What the hell was that?' John's rough hush sounded tight with near-panic, and Sherlock dragged his eyes open. He blinked up at the man who was gripping his shoulders, fingers clamped around his bones as if he were trying to hold him in place. Dimly, he realised that John's wards were folded on top of his own, wrapped around them like the wings of a giant bird.

John's face was pale as lines of concern etched themselves around his eyes. The warm wash of magic swirled around them, emanating from the point where John's hands touched him. The curl of his fingers eased back from desperate claws to rub, just once, along the line of Sherlock's shoulder-blade.

Sherlock's stomach jolted, nervous butterflies shivering awake in subtle pleasure even as his mind grappled with the enormity of what John had done. Not the caress, John was often a tactile friend, at least around Sherlock, but with the magic. He had pulled Sherlock back here as surely as if he had hauled him home by his collar, but how?

'Something unexpected,' he managed, shrugging aside his questions and reaching up to give John's wrist an instinctive squeeze of reassurance. Getting to his feet, he probed the bruise before looking at Lestrade and his men. They were all pressed back against the walls of the room, doing their best to avoid disturbing the evidence while staring at Sherlock as if they had never seen him before. Even Lestrade, who had known Sherlock when his magic was at its most wild, bore the gleam of nervous sweat along his hairline.

A glance downwards solved the mystery of their confusion, and Sherlock narrowed his eyes in interest. The lighter was still in his hand, and now it was obvious why the reservoir was spent. The purpose of the flame was to absorb excess energy that spells threw off. It was normally a harmless way of disposing of the power, yet the scorch marks told their own story. Even more intriguing was the pattern of interlocking circles they created: Sherlock's wards given ashen form. They coiled through the room like the petals of a flower, unfamiliar, exotic sigils to everyone but him. Yet at their centre were a different set, more common and understandable. John's shields had entwined with his own.

The sight made Sherlock falter, but he covered it quickly, turning to Lestrade as if nothing untoward daubed its baffling evidence across the floorboards. 'The demon is still in his realm, but probably not for long.'

'What do you mean?' Lestrade asked, easing himself forward and stepping over the charcoal lines. His gaze never left Sherlock's face as if he expected something from the abyss to be hiding behind his eyes. 'What did you do?'

'I merely observed,' Sherlock replied, not bothering to credit the half-obscured suspicion in Lestrade's voice. 'He's gathering a cult. It was written all over his realm. There were trinkets – offerings from followers – not to mention the iconography: a spider and web.' He paused again, thinking of the moment when the creature had plucked his name from his mind – a powerful token. Except that such things went both ways, because when the demon had murmured Sherlock's name, he had heard the answering trade: as old as magic itself.

'It's called Moriarty.' He uttered the syllables carefully, warding them without a thought. 'Don't say it out loud. All names have power, and his is not the kind you want to try and tame. Someone's planning something, but I doubt they realise the danger.' He turned, his dark coat settling around his body as he headed for the door, ignoring the DI's spluttering protests. 'Keep your ear to the ground. The cult's not small – it should be easy to find.'

'And the conjurer?' Lestrade called out, jamming his hands on his hips as Sherlock glanced back over his shoulder, taking in the bloody room and the pale faces of the police within.

'A journeyman, judging by the books on the shelves. It's not beginner's magic, but nor is it advanced. Job applications on the table suggest he's new in the city and looking for high-paying employment. I suspect he was an initiate in the cult who barely believed in the demon to begin with and thought he would try to summon it for his personal gain.' Sherlock shrugged. 'He couldn't afford the assistance on offer.'

'Eaten?' Donovan looked sick at her own question. For all her bitterness the woman was intelligent, and she had the sense to look to Sherlock for the answer.

'Thrown away,' he replied, his memory settling once more on the strange, uncertain realm he had seen. 'The demon wasn't hungry; he's too well fed for that.' He remembered the mirthless smiles, the dark, abyssal eyes and the intellect in those depths, as engaging as it was repulsive. He knew that look well; he saw it in the mirror more often than not.

'He was bored.'


John watched Sherlock's reflection in the taxi's window, pretending to give a damn about the view of London beyond the pane of glass while all his attention was fixed on the man at his side. He was used to Sherlock's magic by now, from arcane circles on the living room floor and eyeballs on the kitchen table to the more subtle, elegant spells that he wove around himself at every moment, but what had happened in the bedsit was in a different league.

There were already whispers about the things Sherlock had done in the past – mutterings among Lestrade's men about dodgy deals and power that touched on the wrong side of the law. John did not believe a word of it. Their fear stemmed more from jealousy than any concrete evidence, but tonight's events would not help to silence the rumours.

It was rare that Sherlock went on the hunt like that, leaving his body absent while his being was off elsewhere, chasing the trails of a case through worlds the rest of them could only imagine. Such things were normally restrained to the stronghold of Baker Street, where his physical form would be completely safe in its undefended state. John was not sure whether Sherlock's actions tonight had been a sign of trust in the people surrounding him, or a product of his endless curiosity.

Either way, it had backfired. John had known it the instant the icy prickle of Sherlock's wards had come to life. He had sensed a problem when the body hunkered on the floor – still breathing, still living, but empty all the same – had turned pale and begun to sweat. The fire that danced at the lighter's peak, sparking happily with the fuel the magic sent its way, had stuttered, turning sickly violet before unfurling in a heatless blaze to chart the circumference of Sherlock's ferocious shields.

Lestrade and his men had staggered back. John had marched forward.

It was a stupid thing to do. Now, in the aftermath, he could hardly believe his own idiocy. Sherlock's wards, already keeping out something else, should have repelled him – should have turned him to nothing but ash and dust with their vigour – but instead they had parted like silk. John could still feel the worshipful caress of them across his skin and hear the harmony as they resonated along his own, meeker protections. They had mingled until he was able to stand at Sherlock's side and grip those shoulders tight, desperate to somehow call him back.

Surprisingly, it had worked. Sherlock's muscles had jerked immediately, a presence finding its home once more as the mundane symbols of John's wards burned into the floor at their feet.

It shouldn't have happened like that. Shields weren't supposed to blend and merge. They were repulsive, forcing away all threats and interferences. Yet John had been welcomed like a lover into their embrace, and that wasn't – he and Sherlock weren't – they were friends, nothing more.

Swallowing tightly, John tried not to let his thoughts linger on the occasional hot moment that sometimes flourished between them after a chase, or quiet evenings where unusual contentment found them both. He would be lying if he said he didn't wish he had more with Sherlock, but the man had made it clear that work was his top priority, and John knew Sherlock better than to believe that might change.

No, they had something incredible – the kind of friendship John had not believed existed until he limped into Sherlock's life – but was that enough to make their magic act so differently? Had it always done that and they had never had the chance to notice, or was it something new?

'You have questions.' Sherlock's statement was hoarse, and John saw him fingering the bruise at his jaw again as if fascinated by its presence. The unconscious gesture was enough to set John's teeth on edge, and he folded his arms, running his tongue over his lip as he glared at the floor.

'What were you thinking?' he demanded at last, pitching aside the more personal bafflement over the wards and their behaviour. He did not think he was ready to face Sherlock's cool logic on that topic. Instead, he let his mind drift back to the demon. 'You said yourself that whoever summoned that thing got more than they bargained for, yet you still dove right in, dashing off where none of us could follow.' John straightened his shoulders, glancing in Sherlock's direction. 'You know his name, and you can't for a minute make me believe he gave you that for free.'

Sherlock looked at him, his capricious eyes gleaming silver as John shifted beneath the scrutiny. 'I'm surprised you're aware of its value,' he mused at last. 'I thought you had no interest in summoning.'

'No aptitude, either, but I remember the classes on it at school; the ones you probably deleted. It would be illegal if the government didn't find it useful.' John thought back to those endless days in the classroom, burdened by the dark, uncertain facts of conjurations and summoning. 'To have power over a demon, to really bind it to you, a mage needs to know its full name. Without that –'

'You have nothing but trouble,' Sherlock finished. 'I didn't get his entire name. Normally there are laws that demons must obey, superstitions that even out the balance. A demon cannot take something from a protected practitioner, not directly. It has to deceive or trick them out of what it wants: information, their freedom, their life...' He paused, glancing away to stare out at fey-lit London. 'He didn't play by the rules, breached my shields and stole my name – my full name. Part of his flowed back along the connection.'

John closed his eyes as a chill washed through him, surfing over his muscles and seeping into his blood. Everyone with even an ounce of magic in their veins knew that names had power. It was an ancient Wyrd. Once, back in the dark ages, they had been used to target spells. Now there were far more people than monikers in the world, and more efficient ways had been found.

'What could he do with it?' John asked, leaning forward to pay the taxi driver as the vehicle pulled up to the kerb. 'Can he get to you?'

'Not through normal means,' Sherlock replied, crooking one finger in emphasis and making his wards sing. It was a high, crystal symphony of music, lilted with the ethereal air of violins. The sound was so familiar that John's tense muscles uncoiled, falling torpid beneath his skin. 'Not in this realm, anyway. In his own, it could be another matter, and it might make any stand-off with his cult more complicated if they can develop spells to specifically hide themselves from me.'

A subtle, wicked smile curved Sherlock's lips, one that said he was already a dozen steps ahead of the demon in question. He stopped beneath the street-light at the corner of the road leading to Angelo's, and John shifted back, allowing himself the pleasure of watching Sherlock work.

God, but he was a good-looking man, striking in almost every way. When he had first set eyes on Sherlock, John had wondered if he used a glamour, because surely no real person could be that strangely unique. However, that kind of magic took a lot of effort to maintain, and John had never seen him look any different. Even in a fit of pique, or lost in sulks, or up to his elbows in a bizarre mixture or arcane and organic chemistry, Sherlock still caught John's eye. No, it was genetics, rather than any spell, that gave Sherlock their blessing.

Yet in moments like this, when Sherlock's focus narrowed down to the pursuit of a single result, he seemed to glow: a man with more purpose in one moment than most people found in their lifetimes.

'Why do you always do this here?' John asked, wincing at his interruption. Yet Sherlock did not complain as he cupped his hands in front of him and gazed sightlessly into the empty air between his palms.

'It's a nexus,' came the reply. 'Three church spires, one cathedral and fourteen statues with spears, staffs or other linear objects in their grasp stand within a short distance from here. The majority of them direct power to this point. Can't you feel it?'

'Not everyone's as sensitive as you,' John reminded him, watching as tiny motes of light began to spark into existence, sending out little, happy sounds as their carmine glow lit Sherlock's cheekbones. 'Mostly all I feel when we're near Angelo's is hunger.'

'Then we had better feed you,' Sherlock replied, bending his head to whisper something before spreading his palms wide. The air stirred, the wind scented of the warm tropics rather than England's frigid bite, and John watched the sparks dance away, darting down alleys and into the dark, forgotten places of London where many of Sherlock's informants made their homes. 'It will probably be an hour or two before we have an answer, anyway.'

Wordlessly, John fell in at his side, matching Sherlock's easy stride as they entered the restaurant and sat at their normal table. Angelo was his usual, genial self, singing Sherlock's praises as they were plied with wine, food and the obligatory candle. John did not even have it in him to protest, not now when his stomach was growling for sustenance and his heart felt bruised with concern.

'You think they'll find the cult?' he asked, jerking his head to indicate the vanished stars. He leaned back as his dinner was placed in front of him, smiling his thanks as Sherlock shrugged his shoulders. As usual, there was no meal for him, and John fought down the urge to offer Sherlock morsels from his plate.

'The sprites will spread the word, and someone will bring something back to us. There were too many offerings there for this to be something people can hide. We just need to listen to the whispers.'

'And if there aren't any?'

Sherlock glanced his way with a hint of a smile. 'Then there are others I can consult, if I must. You know my methods by now, better than anyone else.'

John picked at his pasta, letting a thoughtful silence settle over the table. He had seen Sherlock in action within five minutes of meeting him. Not the magic, which came a couple of hours later, but the man himself. Sherlock saw everything; his powers of observation and deduction were stunning. It was those, initially, that had led to Sherlock helping the police. He looked at a murder scene and saw what everyone else somehow missed – spells had nothing to do with it.

That was probably part of the problem. It was not some curse or incantation that enabled Sherlock to perceive the finest details of the world around him: it was simply his nature, and most people found it more eerie than intriguing. At least Sherlock's conjurations were something everyone could begin to comprehend, but him knowing every secret they had? That's what made people talk.

It had been Donovan who told him, her voice low and hushed, about Sherlock's enjoyment of murder scenes and the mutterings that he had sold his soul in exchange for all-seeing eyes. John had been stupefied, not so much by the words, but that one mage could say that about another. For an individual to willingly relinquish all that made them who they were as a person, both good and bad, they had to be beyond desperate. Even bleeding out in the hot, arid terrain of Afghanistan, John had not reached that point. Not that he would have been able to do it even if he wanted to. You had to be powerful to make your request heard, and John's magic didn't have that kind of strength.

Sherlock's was another matter. People only had to look at him to realise that his capabilities far exceeded the average. Then he opened his mouth and removed all doubt that he was something out of the ordinary: aloof and proud, distant and exceptionally talented – it was no wonder people looked for something to diminish his abilities – to make them somehow lesser and vile.

'And you never question the things I can do.'

Those words made John glance up, swallowing his latest mouthful too quickly as he realised that Sherlock was watching him, reading him as easily as he had done all those months ago when they had met in the lab at Bart's. It took him a moment to pick up the threads of the conversation, and he reached out for his wine, looking back at Sherlock and wishing he could see something – any emotion – beyond the incandescence of curiosity.

'Would you give me a straight answer if I did?' he asked, shaking aside his own question a second later. 'I know you've not done what people say. Only an idiot who has never seen someone without a soul would believe you'd lost yours.'

That caught Sherlock's attention, his eyebrows lifting a fraction as he deduced the particulars. This time, when he spoke, his voice was softer. Even Sherlock had finally grasped that the war was not something John liked to discuss. 'Afghanistan. Prisoners?'

John nodded, trying to ignore the phantom assault on his senses: dust and blood, the distant echo of gunfire, a body so mutilated it was unrecognisable but for the haunted, hollow emptiness of its eyes. 'You can't sell someone else's soul without their cooperation, right?' He waited for Sherlock's nod before continuing, 'They tortured them until it was their only escape – until they willingly agreed to the transaction. You only had to look at them. They were –'

'Dolls.'

Sherlock's answer made John glance up sharply, trying to discern whether it was research or personal experience which had led him to that conclusion. He was right. The soulless moved, would even speak in dead, empty tones and interact with their environment, but there was no emotion there. Nothing could drag a glimmer of sentimental response from them: neither joy nor horror.

'There was a case, not long after I started helping Lestrade. He was a sergeant then: no Anderson, no Donovan, just him desperate for a promotion.' Sherlock drummed his fingers on the table in an absent gesture, ignoring the faint gleam of blue that shone over his cutlery as he did so – his wards making their presence known.

'A serial molester was doing the same thing to children, assaulting them until they begged him to take what he really wanted. He sold their souls for more power of his own.' A crease interrupted the smooth line of Sherlock's brow: a faint sign of distress that most people would have missed entirely. 'Even vacancy isn't like that. When I'm on the hunt and my body is empty, I'm gone. I have to fight to feel anything at all. They were still present, still aware, but they didn't care about anything.'

'You're nothing like that,' John replied. He doubted that Sherlock was looking for the reassurance and half-expected him to sneer at it, but instead there was a hint of a smile in reply. 'Anyone who has seen a soulless once can identify them immediately.'

Sherlock made an uncertain noise, turning back to look out of the window. The fleeting moment of connection was gone, and John returned his attention to his dinner as he listened. 'There are theories that suggest it's not always like that. It's only if your soul is consumed while your body lives that you become so – distant.' He shrugged. 'If you're a powerful mage and your soul is of use to a demon as something other than sustenance, the results may be different. Many people entered such deals during the middle-ages, and none of them are reported to have behaved in the same way as the soulless we know of. They kept their minds, at least.'

'So someone like you …' John let the question trail off, watching Sherlock's reflection in the glass.

'I don't know what would happen, and I have honestly never been tempted to try,' Sherlock replied. 'What could I want so desperately that would make me sell my soul? What could possibly make me surrender the part of myself that makes me who I am: the source of my magic, my self-control, everything?'

'Knowledge? Power? Wealth?'

'With the right books and enough time I can teach myself anything. Knowledge is power, and wealth often follows. I don't need a demon's assistance for that.' Sherlock's disdain was clear, as if such mundane desires were beneath him, and John hid a smile as he finished his dinner. 'Are you ready to go home?'

'Yeah, are we walking?' John already knew the answer. The sprites tended to alarm taxi drivers, and vehicles often acted like a magical Faraday cage, cutting their passengers off from the city. For John's part, it meant they felt a little cold, but if Sherlock spent more than twenty minutes in a cab, he became irritable and twitchy. Besides, on foot might take longer, but it was better for their health – both physical and financial.

London's night parted around them as they spoke in quiet voices, the rhythm of their footsteps underscoring the facts of the case as Sherlock spun out the details for John's attention, his knowledge slowly easing the tension in John's chest. Like this, alive and exuberant with the promise of a puzzle, it was difficult to imagine that Sherlock – compelling, intelligent and far from naïve – could be in danger from anything harboured in the other realms.

No, he would solve the case, the cult would be gone, and the demon would be cut off from the world once more.

Simple.


Winter air sleeted into the flat through the windows, open wide for the few lingering sprites that had yet to return. It had been a week since Sherlock had pushed his way into Moriarty's realm and learned of his cult, but still there was nothing. Around him, the last of the conjuration spell faded, taking the outline of the little girl with it. Appearances could be deceiving. The spirit had owed him a favour, and as such had appeared in a benign form. Unfortunately, she returned to him empty-handed.

Sherlock scrubbed his fingers through his hair, flicking through the curls as if he could pitch his thoughts aside. He was being Obscured, obviously, yet the fact that the members of this cult were able to hide themselves so thoroughly suggested they had more power at their command than he had originally estimated, and they seemed to be gaining strength.

More bodies had turned up: tribute for the demon, judging by the cobweb patterns carved into their skin. It was crass and barbaric: a human touch. The demon was too poised for such theatrics, but his cult clearly had other ideas. Mortal, careless, they should have exposed themselves by now, so where the hell were they?

'Christ, Sherlock, it's freezing in here!' John's voice dragged him out of his aggravated musings, making him look up. John had been at the surgery, and a glance at the clock and then the window told Sherlock that night had drawn in. Another day gone, and he was no closer to knowing the truth. 'Have you even moved?'

John padded over, still huddled in his jacket, and reached out to touch Sherlock's arm. He did not wait or ask permission, just wrapped his fingers, warm from his gloves, around Sherlock's wrist and muttered a curse at the chill he found there. 'You prat. What are you doing sitting with all the windows open and your shirt-sleeves rolled up?'

'Trying to solve the case,' Sherlock replied, not caring that he sounded like a petulant child. 'Everyone is coming back with nothing. I've been forced to ask Mycroft for assistance.'

John paused, a huff of surprise catching in his throat before he hunkered down at Sherlock's side, clasping Sherlock's left hand between his own and rubbing some life back into his fingers. Those blue eyes lingered critically on the three nicotine patches dotting his arm, but John knew better than to comment by now. Instead he kept up his steady caress, flexing Sherlock's frigid knuckles before moving on to the other hand.

Sherlock watched what he was doing, following the glide of John's skin as his heart beat hard beneath his ribs. He could feel the calluses on John's fingers and his dry palms as they stroked back and forth, too slow and gentle to be truly clinical. They performed no magic to bring heat back to Sherlock's skin, but it worked all the same, making his flesh tingle and the crests of his cheeks flush with warmth.

'You've been summoning,' John muttered, taking in the hints of chalk on the floor and the flipped back rug that exposed the bare boards. 'I know you're one of the best and that Baker Street is shielded, but you shouldn't be messing about with this without your personal wards up!'

'They are up,' Sherlock murmured, his thoughts changing the instinctive flow of energy so that the bubble of protective magic made itself visible. 'You walked straight through them.' He glanced away, pulling his hands free of John's grasp as he did so. Not that the man's heat left him; his weren't the only wards behaving strangely. He could feel John's furling around him, enclosing him in their depths like a cocoon: doubly safe.

'Oh, I – I didn't –' John looked confused and embarrassed, as if he had been caught doing something rude. 'Sorry.'

Sherlock thought he would ask why spells that should be protecting them both from everyone, including each other, were instead twining together with such elegant ease. The shadows of questions dwelt in John's expression, and Sherlock watched, helplessly following the swipe of John's tongue with his gaze as he licked his lips.

A knock at the front door cut through the air, curtailing anything John might have said. Clumsily, Sherlock got to his feet, listening as Mrs Hudson checked the protections on the threshold. He could hear them humming in irritation as they always did when Mycroft darkened the doorstep, and he fixed his face into an indifferent expression as his brother entered the building and climbed the stairs.

'You've had no more luck than I,' he said in greeting, his frustration temporarily eclipsed by the satisfaction of Mycroft's failure. He would have been disgustingly smug if he had found something that Sherlock had been unable to discern.

Mycroft gave a disdainful sniff, taking in the flat with his usual level of scrutiny. On the surface, he looked disinterested, but Sherlock knew better. His brother would examine everything, probing the magical and mundane for any significance. 'The cult is completely veiled. I can't find them on CCTV or in the mists.'

'I don't know why you bother; you're a substandard seer at best.' It was a useless barb. Brilliance ran in the Holmes bloodline, and Mycroft was masterful at attuning his mind to the interwoven strands of potential futures that lay before every human being on the planet. More to the point, he had the control that so many lacked, allowing him finite focus. Alternatively, he could turn the ability off if he had to. As such, he had not lost his mind – at least not yet.

'Is that why you've veiled yourself and John so thoroughly against me that I get a headache just trying to find you?' Mycroft gave Sherlock a cool glare. 'Must you use such an obnoxious glow on that particular ward? It makes attempting to divine anything within a mile radius of Baker Street rather like looking into the sun.'

'Someone's got to keep you on your toes,' Sherlock replied. 'If you could see everything that we were going to do, you'd never bother leaving your desk. Do you have anything for me or not?'

'Uh, Sherlock?'

John's voice made him turn to see his flatmate by the window, smiling at the glowing star that hovered there. The sprite made dizzying, happy curves around him like an orbiting sunlet, occasionally nuzzling up to his cheek or his open hand like a cat. The noises it made were euphoric, far more suited to the bedroom than anywhere else, and it was all Sherlock could do not to blush. First his wards and now this – emanations of his magic fawning over John like...

He cut the thought off, deliberately not looking in Mycroft's direction. He could feel the smug surprise radiating off his older brother as it was, and he swiftly pulled the sprite towards him and away from its rapturous admiration of John. The star came grudgingly, weaving through the air to settle on his palm. It was not alive, not really, but its heat kissed him as it dissolved into his skin, allowing its findings to flow into his mind like syrup.

A jumble of impressions – darkness, rot, the smell of the river – and then a glimpse of a street-name before the images faded: Rotherhithe Street. Finally.

'Got them. Come on, John!'

'What about Lestrade?' John asked, chucking Sherlock his coat as Mycroft stood aside to let them pass. 'Shouldn't we call him?'

'Not yet. Not until I'm sure there's something there worth investigating.' Sherlock pulled on his gloves, glancing back at his older brother. 'Show yourself out, Mycroft.'

'Have a care, Sherlock. I might not have found much about the cult, but I did find something on the demon: class one. You know what that means.'

'Well, I don't,' John cut in, looking between the two of them as Sherlock digested the information.

'He's considered too powerful to bind,' Mycroft explained. 'The few, previous attempts to which I have found a reference had apocalyptic consequences. The last time an effort was made to summon and tame him appeared to result in the Black Death. I recommend you take your gun.'

John's expression took on that shuttered, stoic tension that Sherlock knew well: the face a soldier wore to war. He did not even look Sherlock's way for confirmation as he went to retrieve his weapon, leaving the two Holmes brothers alone.

Sherlock clenched his teeth, waiting for the inevitable. He could practically hear Mycroft's thoughts from where he stood, rife with ridiculous assumptions.

'Mummy will be so pleased.'

Sherlock flinched, glaring at his older brother as he spat, 'Shut up, Mycroft. You're too busy staring into the future to focus on the reality that's right in front of your overly large nose.'

His only response was a faint smile, and Mycroft shook his head as he walked down the stairs. 'I don't need magic, Sherlock. I know your views on sentiment echo my own, but if you must feel for someone, you could do far worse than Doctor Watson.'

The spell snapped at Mycroft's skin-tight wards, raising a brief shower of cerise sparks where they touched: nothing but a toothless dog biting at his heels, but Sherlock felt marginally happier for the display. With a flick of his umbrella tip, Mycroft bade him farewell, stepping out of the door and leaving him to shift from foot-to-foot, waiting impatiently for John.

'Come on!' he called up the stairs, rolling his eyes as John thundered down to meet him. 'What took you so long?'

'If I didn't have to hide my gun from you to stop you shooting the walls, it wouldn't take so long to retrieve it,' John pointed out tersely as they hurried from the flat and slid into the taxi Sherlock flagged down. 'What's the plan?'

Sherlock rubbed his thumb over his brow, narrowing his eyes as he gave the question some thought. 'They'll have a base of some kind. That's what we're looking for. Probably underground. There's a dis-used sewage system near Rotherhithe Street; it used to be a drug den.'

John stiffened beside him, and he could almost sense his flatmate struggling to find the right words for his next question. 'Are you – personally familiar with it?' he said at last. Sherlock's history of pharmaceutical abuse was not something they discussed. It made John uncomfortable, so he left the topic closed.

'Yes. From what I can recall, it's serviceable for the purposes of a cult such as Moriarty might gather.'

Someone else might have questioned the accuracy of memories no doubt addled by drug use, but John kept his mouth stubbornly shut. If it weren't for the lines etched around his lips and eyes, Sherlock could almost believe he was indifferent. However, a heavy silence dragged down around them as the cab continued its journey, weaving through the streets of London before depositing them at the end of the road in question.

Mundane senses were driven to obscurity, overwhelmed by the tingling, electrified sensation of power in the air. The river was a dead wall of nothing to the north, almost overwhelming enough to hide the tell-tale signs of something amiss, but it was the iron manhole covers pocking the street that acted as conductors for the magical charge, shining like beacons.

'Something's here,' John muttered, scratching at the nape of his neck. 'Even I can feel it. It must be like a neon sign to you.'

'Text Lestrade. Tell him he needs a team at the Rotherhithe culvert. We'll go in and see what we can find.'

'Shouldn't we wait for them?'

'And have them trample all over the evidence?' Sherlock shook his head. 'I need to get a good look before Anderson and his idiots intervene.'

He was vaguely aware of the slow peck of John's fingers over the keys as they strode forward. Every entrance they passed was warded, dense with angry, offensive spells, and Sherlock ran his tongue over his teeth as he considered his options. The culvert was probably the best choice. Larger entrances were harder to protect, so while the manhole covers would be practically impenetrable, the sizeable outflow would be the weak point.

Leading John ever onwards, he ignored the squelch of his shoes along the bank of the Thames, foetid now at the ebb of the tide. The culvert gaped like an open mouth, dark but for the gleam of the barrier in his other-sight. The spell was weak and transient, no doubt this was the main point of entrance and exit and therefore constantly disturbed.

It took Sherlock less than a minute to open it, leaving a faint ring of magic behind – enough to stop the breach from raising any alarms. Water splashed beneath their feet as they walked, and Sherlock let his body lead the way: an old, routine journey coming back to haunt him. Two right turns, then a left, along almost-forgotten tunnels until, at last, where there had been only darkness, there was a hint of light ahead.

When people pictured cults, they often imagined robed pseudo-monks and a cruel mimicry of established religion: altars and prayer-books. The truth was that such groups, when they formed, were more like a gang. The members were usually dressed in their normal clothes, fighting and arguing among themselves. The altar could be anything, from a stone monolith to an upturned milk-crate. The only stereotype that rang true was the human sacrifice.

Sherlock crouched at the tunnel mouth, examining the room beyond. Power lingered around the corpses, three in all. From this distance, he couldn't be sure, but he doubted he would find any signs of a struggle. Lives willingly given then – powerful fuel for the demon, should he need it. There were bowls of fluid on the altar – blood judging from the aura they gave off – but there was no-one else to be seen in the circular chamber.

'Maybe no-one's home?' John whispered, and Sherlock looked across to see him crouched on the other side of the entrance, his gaze astute as he searched for threats. 'What now?'

'Let's see if we can find out what they had in mind,' Sherlock replied, carefully stretching out a sensory spell to check everything was as bare as it seemed. He could discern John's steady pulse, slightly fast, and the patter of life from rats and other pests. Beyond that, the place was deserted. 'Be careful,' he whispered. 'I can't sense anyone else, but they could still be Obscured from me.'

Quickly, they moved forward, working in easy tandem. It was obvious that the cult were not living here. There were neither sleeping bags nor any signs of habitation – it was merely a meeting place. The blood in the bowls was cold – days old – and clotted in a miasmic mess. The bodies had been scavenged by the rats, and the stench of their remains turned the air thick and repulsive.

Sherlock clenched his teeth against the sharp, hard edge of magic that cut through the room. There were circles all around the altar, running into one another in a dizzying swirl of symbolism. Some were familiar, but most were a mystery even to him, and he cocked his head in fascination.

Several were designed for summoning, the runes cast like hooks into the infinite seas of the other realms, but others were for tribute: channelling energy through to a specific place. All around, far-flung and firm, were protective markings, which suggested someone in the cult had the moderate intelligence to know they were playing with fire. The construction of the designs implied none of the mages were of a higher level than journeyman, but...

The blast of a gun rang through the air, its echo clanging in his ears. Sherlock ducked instinctively, his teeth bared in a snarl as he glared in the direction of the noise. Echoing, fleeing footsteps followed, and Sherlock's spells reacted automatically. They raged outwards, tearing through everything within the cult's shrine to neutralise the threat. However, before he could follow through and wreak his punishment on the running gunman, a gasping, choking sound pulled him back, and the world fell blank and still as he realised where the bullet had found a home.

'John?'

The Browning clattered beneath Sherlock's shoe as he stumbled closer, falling to his knees and plucking at John's jumper. The cheap wool was soaked and hot with a growing, cardinal stain. Sherlock knew blood, saw it every day, used it, touched it, read its story – but not like this, not John's, spreading like a cancer around the hole high in his chest.

He applied pressure, the cool leather of his gloves rapidly growing warm as his mind, normally so linear, skipped and slid, orbiting helplessly around the one fact that burdened his mind like a lead weight.

John could not survive this.

That tanned face was unnaturally pale, already starting to grey as John's blood pooled beneath him in an unstoppable torrent. He was trying to say something, attempting to speak around the pain and the shattering shivers of exsanguination, but the words cracked and failed in his throat, drowned out amidst the fury of a losing battle.

Sherlock shushed him, pretending that his eyes weren't going bright and his vision blurry with the startling presence of genuine tears. This was – it was a nightmare – it had to be. He would wake up back at the flat and John would nag him about rituals on the table and chalk on the floor and not be here, like this... leaving.

John's fingers, kitten-weak, looped around Sherlock's wrist above his glove, the slick of blood sticky on his skin. At last, he forced two syllables free as if they were all he had ever wanted to say:

'Thank you.'

'John!' Sherlock's throat closed as those blue eyes slid shut, his mind scrabbling with useless facts. John was still breathing, barely, but even if he called an ambulance it would never get here in time. How long did John have, seconds, a minute? No time for anything at all, not even a damn spell could make this better.

Unless...

Like a black flower, and idea unfurled in his mind, touching his thoughts with noir potential. It was a desperate concept, as likely to send Sherlock hurtling into the grave at John's heels as it was to bring his friend back to life, but he could not let this go. Too much lingered between them for him to accept this twist of fate, and he bit his lip as his mind raced.

There was no time to consider it logically, nothing beyond the gut-wrenching spin of yes/no before the name fell from his lips. Not John's – not this time. Sherlock spoke, his power exposed in every syllable: a lush temptation to capture the attention of the creature he knew would be listening.

'Moriarty!'


Loud voices called John back, puncturing bottomless oblivion and dumping him ruthlessly into the waking world. His head was pounding and his ribs ached as if he had taken a punch to the chest, but as his mind replayed the last few moments of consciousness, he realised the impossibility of his situation.

The bullet had killed him: he knew that as soon as it ploughed into his flesh. He had never even seen the sniper, hidden off in the shadows. His memory was patchy: a collection of disjointed images. Sherlock applying pressure, looking as pale as if he were the one who was dying. Tears: startling stars in those dazzling eyes – real for once – and the solid weight of regret that had settled around the shrieking pain in John's body, because he did not want this to be how they parted ways.

'John, bloody hell! Are you all right?'

He rolled his head to stare at Greg. The DI and his men were picking their way across the room, the protective spells around them crackling and hissing with every step. It was no wonder. Something had changed while John was out. Where the air had been rank with dormant power it now felt like the moment after a lightning strike, so vivid it made his eyes ache.

Belatedly, he realised there were scorch marks on the walls, and that the floor beneath him was cracked and glassy – superheated. He had never seen anything like it, and steadily, his dazed mind started putting the pieces together.

He jerked upright, ignoring the screaming protests of his body as something clinked beneath his left hand. His fingers closed around it automatically, and he stared down at the bullet, misshapen from impact, covered in a thin layer of blood, but harmless. It had been in him. He had felt it cut through his lung and the major blood-vessels at the top of his heart, bringing with it death's brutal bite, so how...?

Abruptly, his focus shifted, looking beyond his own hand to the figure that lay on the floor a short distance away. Sherlock was close enough to reach out and touch, and John's shaking fingers caught in the heavy wool of that black coat, plucking fitfully at the scarf as he sought out a pulse. Questions shrieked through his mind, colliding with dank, noisome fears as he pressed his fingers hard over the lingering green blemish of the demon's bruise.

'John?' Lestrade's voice was gentle, but John shook his head as he tried to pick out anything like life in the warm body. It seemed to take an age, but his quest was answered by the thready thrum of a heartbeat.

'John, there's an ambulance on its way. I need to know what happened.' He became aware of Greg crouching down at his side, a steady hand clasping his shoulder and giving him the tiniest of shakes. It was a dangerous, trusting thing to do. With this much evidence of a massive spell filling the room, John was surprised the DI was willing to touch him at all, in case he was something else wearing John Watson's face. 'Whose blood is that?'

At first, John thought he meant the stuff in the bowls on the altar, and his fingers tightened hopelessly in Sherlock's scarf before he realised that there was not much left of the dais. The stone had been split clean in two, and the items on it were nothing but dust and shrapnel. There was no trace of the thick, black gore that had stood in pride of place.

'What blood?' he managed at last, his lips cold and numb as he spoke. His voice sounded hoarse, as if he had been screaming, and he cleared his throat. It was easy to move his hands and search Sherlock's unconscious form for injuries while his mind floated, disconnected and disbelieving.

Something heavy covered his shoulders, and he blinked to realise Greg had shrugged out of his coat and draped it over John's back. It was a disturbing burden, an anchor into a reality John did not want to face, and he drew in a stuttering breath before dragging his gaze from Sherlock's prone form.

For the first time he took in the DI's expression: confusion and horror mingling together as those brown eyes dropped to the front of John's jumper. Automatically, John followed, seeing the mess all across his torso. It made him look like a walking corpse. If it weren't for the heartbeat thrumming in his chest, he would have checked his own pulse.

Suddenly, it was as if he were another piece of evidence, something damning, screaming its accusations for all to see. Only the need to keep touching Sherlock prevented him from folding his arms across his chest, and he found himself staring at the bullet hole in the jumper's weave – the epicentre of his own destruction.

Numbly, he turned back to where he had been lying, half-expecting a lingering pool of blood there like a lake. However, bar a faintly grisly stain, the floor was clean. He had been losing it fast – had seen it pouring out over Sherlock's hands – so where was it? There might be half-a-pint on his jumper, sodden and heavy, but there had been much, much more. Was it all back inside him?

What the hell had Sherlock done?

Wordlessly, he shook his head, his shoulders lifting in a shrug. 'It doesn't matter,' he managed, his words slurring. 'We need to get Sherlock to –'

The sound of someone's quick, sharp stride interrupted him, and John blinked up as Mycroft, of all people, marched into the room. He had never seen the older Holmes move with such focussed purpose before, so fast that Anthea and a few nameless men in suits had to hurry to keep up. With the half-hysterical tones of shock, John thought that Mycroft's expensive brogues would be fit for nothing but the bin after walking through the sewer, but then the man spoke and the fretful emotion ebbed.

'Thank you, Detective Inspector, I'll take it from here.' Gone were the smooth, benign tones Mycroft so often employed. His enunciation remained, educated as always, but now there was steel in his voice that made John believe Sherlock's assertions that his brother actually ran the country. Around him, the people Sherlock sneeringly called Mycroft's thralls were taking readings and muttering incantations, their faces set in grim lines as they worked. The assembled officers could only stare in bafflement as they were gently ushered to one side.

'Mr Holmes,' Greg said, his voice tired and disbelieving. 'This is a police investigation.'

'And now it is a government one, Detective Inspector.' Mycroft's voice sounded odd, a little soft behind the veneer of stress, but John did not pay it much attention as he stopped at his side. He did not crouch down, not like Greg, but when he spoke again it was in the delicate tones someone might use to a person standing on the precipice of a rooftop, about to jump.

'John, I need to know what happened. I can make my own deductions –' He looked at John's jumper, and then the bullet where it had been abandoned by John's knee. '– but there is no room for error. I need to know what Sherlock did.'

John swallowed, trying to breathe around the lump of fear like granite in his chest. The instinct to protect Sherlock from the judgement of others, to bundle him off and hide him from the public eye, was almost overwhelming. They could go somewhere quiet and out-of-the-way, where it wouldn't matter what had happened.

Except that the police and Lestrade were right there, and Mycroft was watching him, hawk-like and intense, waiting for some kind of answer. There was no way they could escape. What choice did he have?

Slowly, with every word feeling like a betrayal, John began to speak.

'I was – I don't know. There was someone here. We checked before we came in, but he must have been hiding. We were examining the altar when he fired.' John looked at the ammunition again automatically, relaying the information it could give him, which wasn't much. 'He was using a Dragunov rifle; I was hit. The silver bullet went straight through my shields.'

'Here?' Mycroft went to touch the breach in John's jumper, looking as if he hated to ask something so obvious but needed the confirmation. However, before he could get close, John's wards snapped, abrupt and vivid, adding a prickling, warning edge to the air that made Mycroft duck his head in apology and Greg lean back out of range.

'No, I always wear clothes with holes in them,' John muttered, drawing his hands back from Sherlock's motionless body to scrub them across his face. Now, he kept his voice quiet, careful not to let its echoes carry to unfriendly ears. He was not sure what Sherlock had done, but suspicions sat in John's gut, slick and nauseous.

'Chest shot, not quite to the heart, but close enough. I was bleeding out, and Sherlock...' John shook his head, staring blankly at his own knees. 'He was right here, trying to help, but there was nothing he could do. I passed out within a minute or two. Next thing I knew, Greg was here and Sherlock was –' He gestured to his friend, surprisingly peaceful amidst the tension that filled the room. 'We need to get him to a hospital.'

'You're the one who was shot,' Greg pointed out, looking up as a couple of paramedics were led in by Donovan. 'Check them both over, will you?' he ordered, ignoring Mycroft's harrumph of annoyance and looking back at John. 'Maybe Sherlock can tell us more when he wakes up?'

Silence followed that statement, tense and unnatural, and John met Mycroft's eye in one dreading glance, seeing the same fear in the older Holmes that lingered in him. He was a doctor, one who had worked on the front-lines, and he knew there were no spells in existence that could save a life so nearly expired. How many times had he been on the battlefield, holding in some poor kid's guts and wishing that magic could change it all? People didn't have that kind of power, not even mages as capable as Sherlock.

Demons, however...

'How did you know we were here?' he asked Mycroft, moving like a puppet as one of the paramedics cut away his jumper, searching for an injury that wasn't even there. He watched the other one working on Sherlock, following the same rudimentary examination John had conducted before checking for curses or other, more malignant magics. 'I thought you couldn't "see" us.'

Mycroft leaned on his umbrella, staring at Sherlock as if he was struggling to recognise his own brother. 'He has been warding against me since he was six – blocking himself from my sight in the most obnoxious ways possible. When I try to analyse Sherlock's future, or even divine his present, there is nothing but light so dense I cannot glimpse beyond it.'

Now John could see the pallor in Mycroft's face, not just tense, but almost sick with concern. 'I am always aware of it in the same way that others are attuned to the sun or moon in the sky. This evening, while I was sitting at my desk, that light went out.' The tip of the umbrella scraped on the floor as Mycroft ground it into the stone. 'Immediately, I realised something was wrong. I could sense the two of you here.'

'What about now?' Greg's question took John by surprise, and he glanced over at the DI, who looked faintly embarrassed. 'I mean, if you can tell his future, that could save everyone a lot of trouble.'

Mycroft pursed his lips, a mirthless smile curving their thin line. 'My dear Inspector, where there was nothing but light, there is now only darkness. Previously, I could tell if Sherlock would be involved in an event because it would abruptly become shielded from me. Now I see only shadows.'

The paramedic continued to work in silence, going through the motions as if she could not hear a word that was being spoken two feet from her side. However, it was clear she was having trouble finding anything to pursue. Each diagnostic came back clean. There were no curses, no spells and no wards in place – which was unusual for Sherlock, who even had basic shields up when he slept. It was as if someone had simply switched him off, everything, from the spark of his magic to the incandescence of that brilliant mind.

Abruptly, the paramedic jolted back in surprise, fumbling with the slim torch in her hand and flushing in embarrassment. 'Sorry,' she murmured. 'The heterochromia took me by surprise. It's very – distinct.' At the blank looks she received, the young woman licked her lips. 'His eyes –?'

John removed the pen-light from her grasp, his hands steady as he peeled back Sherlock's right eyelid. The pupil responded normally to the illumination, despite the absence of focus, and those same, mercurial colours flecked the iris: tones of blue-green-grey with one tiny patch of gold. The same as always.

It was only when John shifted to the left eye that he realised what had surprised the paramedic, and his stomach sank. There was no trace of ocean hues or starlight glimmers. Instead, the iris was thick, choking brown, so dark it was almost indistinguishable from the pupil. There were no familiar patterns to be found, no radial lines and shifting petal tones, just blank colour: absolute.

Inhuman.


'Told you you'd be back.'

Sherlock opened his eyes, taking in the obsidian tones of Moriarty's realm. There were more trinkets and tributes, and this time the steady drip of fluid punctuated the oppressive peace. Sluggish with shock, his mind took a few seconds to realise that this was a sound he had brought in with him: John's blood, or a representation of it, dripping from his own leather-clad fingertips. He was not corporeal. No doubt his body was back in the real world – the one where John lay dying.

He drew in a deep breath, trying to control the surge of fear that welled up in his chest. It was not terror for his own situation. He had called Moriarty, and he would face the consequences of that, whatever they may be. No, his horror was at the thought of John slipping out of reach with every passing second. It filled him, paralysing his muscles, choking his voice and knocking loose his mind to spin, helpless and frantic with no sure path to follow.

Moriarty stepped forwards, his lips curved in a salacious smile as his eyes burned. 'Tick tock, Sher – lock!' he tittered, his mirth vanishing a second later as his voice became a growl. 'Your pet is running out of time.'

'Change it,' Sherlock bit out. 'I know you can. Grade one – the only thing you can't do without help is get into the real world. No-one's quite stupid enough to let you out. Not even your cult.'

'Why would I want to leave?' Moriarty cried, spreading his arms wide and tipping back his head. 'Why walk in your dull little reality with its faceless drones of humanity when I can stay here and watch them all crawl from cradle to grave?'

'Because you're bored.'

Moriarty froze, an almost imperceptible lack of motion before he spun around. His head tipped to one side, one eyebrow lifting in acknowledgement of Sherlock's point. 'Nothing happens. Here. There. Anywhere.' A grin twitched into place. 'I could set the world on fire. Mayhem but not chaos, no. Something elegant. Glorious. I wouldn't be bored.' His eyes fluttered closed as he stepped forward, his breath ghosting across Sherlock's cheek as he added, 'Neither would you. We're alike, you and I. Together we could bring everyone else to their knees.'

Sherlock did not look away from the demon's gaze, meeting those eyes without a flinch as he clenched his hands into fists, slick fingers starting to turn tacky as the blood dried. 'I'm not here for me.'

'Oh, forget him!' Moriarty shouted, his face contorting into a snarl. 'He's holding you back. Making you feel. He's nothing, no-one!'

The demon took a deep breath, pursing his lips as he reigned himself back under control and flicked imaginary dust from the sleeve of his suit. 'I suppose I should be grateful to the Doctor. It's because of him you're here.' A moue of distaste cinched Moriarty's mouth, tight and disgusted before it vanished. 'So what will you give me, Sherlock? What is he worth?'

'A deal.'

'Well, obviously.' Moriarty sighed, his footsteps echoing in a strange myriad of percussive beats as he paced in a circle. 'You know it won't be cheap. You have to give me something I want.'

Sherlock swallowed, the pressure of passing time raking across his nerves. Normally, he would never attempt something so fundamentally stupid, but if he did, he would take weeks to prepare. Demons were nefarious, and a single word out of place could often spell disaster. Now, he had nothing, no planned contract, no finely-etched clauses, only the most basic and simple of equations – anything to stop John's life drawing to its bloody close.

Only last week he had sneered at the thought of using his biggest asset as a bargaining chip, questioning what he could ever value above something so precious. Now, he had his answer. Moriarty would accept nothing else, and Sherlock had no greater wealth to offer.

'My soul, such as it is and as long as you're able to keep it, for John Watson's life.'

Moriarty stopped with his back to Sherlock, the lines of his body tense as he looked over his shoulder. Surprise was a fleeting thing – a bird freed from its cage to fly over the demon's face before it was replaced with the scimitar curve of a callous grin. 'Oh, but you are desperate. Is that it? That's your deal?'

A tremor wound down Sherlock's spine, making his skin crawl. 'I thought you were intelligent. Do you need me to spell it out for you?'

'Oh, no. I understand.' Moriarty spun around, his stride confident as he closed the distance. His eyes trailed down Sherlock's presence and back up again to meet his gaze. 'I understand completely.' His hand was already held out, the demon's fingers a pale splay in the darkness around him, and Sherlock stared at the mute offering before a smile crossed his lips.

'Do you? Let me be perfectly clear. Doctor John Watson, who lives with me in 221B Baker Street, London, England and is currently bleeding out on the floor of your repulsive little shrine will live, and will suffer no harm from your actions – or mine, if they are controlled by you – in my world or any other.'

'Don't you trust me?' Moriarty murmured, wiggling his fingers meaningfully. 'Don't you worry, Sherlock. He'll be safe and sound.'

'The no harm clause applies to others of my acquaintance,' Sherlock added, watching Moriarty's smile turn brittle.

'Name them,' the demon challenged. 'Quickly. Death comes for your doctor.'

'Gregory Lestrade, Martha Hudson, Mycroft Holmes, Evelyn Holmes.' Names skated through his mind, and one more stood out at him. More a nuisance than a friend, but she was taking care of something for him that could be useful in this situation. 'Molly Hooper.'

'Anyone else?' Moriarty asked, rolling his eyes. 'Your soul is only worth so much.'

'It's enough,' he retorted. 'You want it. It's written all over your face.'

'Oh, Sherlock,' Moriarty purred, tipping his palm up meaningfully. 'You read me so well. Now you know how this goes, shake on it, or your Doctor is no more.'

Sherlock paused, squaring his shoulders as the moment hung in the balance. This was his decision. Seal the deal with the demon before him, or turn and walk away, back to a life haunted by the absence of John Watson. Before he had met the man, the thought of reaching this point had been inconceivable. Now, the concept of returning to the way he had once been, alone and distant from everyone around him, hurt more than he could begin to comprehend.

In the end, it was no choice at all.

He seized Moriarty's hand in his own, the tacky blood sliding between them as triumph bloomed on the demon's face. A heartbeat later, the pain struck, writhing beneath Sherlock's ribs and coiling around something hidden there. It stabbed along his nerves, crippling taut muscles and bringing him to his knees as the pungent scent of old, dark magic filled every breath, rotten and profane.

Each gasp was a labour, as if something were being torn from the flesh of his chest. Words were beyond him as the realm gave a dizzy lurch and a retch caught in the back of his throat.

'Now, how about a few conditions of my own? Moriarty sang, a chortle escaping his lips as he thrust his fingers into Sherlock's hair and pulled back his head, bending so that their noses almost touched. 'Your power is mine, now, and Sherlock? You are strong. Oh, the fun I am going to have with you!'

The hand gentled, stroking over his ear and charting the chaotic twist of a curl. 'No meek little Holmes-doll for me. I own you. You can't communicate any of the details of our agreement to anyone. No blabbing to that all-seeing big brother of yours just whose hands are pulling your strings. And I will pull.'

Sherlock's hiss of pain echoed in his ears, and he forced his eyes open. He may have entered the bargain willingly, but that did not mean he would be a meek, docile thing for Moriarty to command. Not if he could help it.

'Oh, defiance! How exciting.' Moriarty bent his head, his lips brushing the curve of Sherlock's ear as he whispered, 'How useless. Do you know the best part? Do you? One of the things all those boring little people have forgotten? You can't just sell your soul. It's tied to your body, and when it's torn out it leaves a hole. Something someone else can fill.' Moriarty yanked his fingers free of Sherlock's hair as he danced away. 'You were right, Sherlock. I was so bored. Not anymore! Who do you think John is going to see when you open your eyes? You? Or me?'

'You're not –' Sherlock wheezed, his lungs trembling beneath his ribs as he strained for one good breath. 'You should have voiced your limitations before sealing the deal. You're breaking the rules.'

'That's what they're FOR!' Moriarty yelled, flinging his hands out wide.

As if beckoned from the darkness, something else strode forward. The figure was taller than Moriarty, blond and well-muscled with a scar cutting across one cheek. He wore a plain t-shirt and jeans, nothing out of the ordinary, but the lingering echo of mud on his boots gave away his last location: the sewer. It was a subtle hint, one almost lost as Sherlock's attention focussed on the sniper rifle in his grasp.

'You.' The gunman, except he wasn't a man at all. 'You're another demon.' Sherlock closed his eyes, berating himself for his stupidity as he addressed Moriarty. 'The tribute, the rituals. It wasn't to get you out of here; it was to set him free.'

'My tiger,' he replied by way of explanation. 'My little hunter. I couldn't let you get away, Sherlock, and I knew just who to hurt to bring you running. You were looking for mortal life in that shrine – too obsessed with the case to bother searching for anything more. You led your doctor right into the sights of the gun.' A breath of air stirred, and Moriarty was at his side once more 'Now you're mine.'

His last word was loaded with magic, a red-hot brand that struck Sherlock through-and-through. Power surged anew in a crashing, towering wave that bore him to the ground, his face pressed to the uncertain floor of Moriarty's ghostly realm as agony ripped through him. His vision faded, wavering between pitch darkness and intense light as bells rang in his ears, shrill and discordant. Only one sound brought him anything like comfort: Moriarty's hissed words, tight with their own kind of pain.

'Stop fighting it! We had a DEAL!'

Sherlock's thoughts collided, splintering into fragments of delirium as he tried to focus. It felt as if he had a foot in each world, both moving in opposite directions and gradually tearing him apart. Moriarty's touch burrowed through flesh-that-was-not and insubstantial bone. The demon's fury was palpable, his strength rapidly depleting as Sherlock blocked him at every turn.

At least he could fight without fear of retribution. It was the magic that forged the deal which would judge whether the terms had been breached and mete out a punishment, rather than the demon. Perhaps Sherlock's conditions had been imprecise, but they worked in his favour as much as against him, and Moriarty had said nothing about Sherlock being a willing puppet for him to control.

He lost himself, somewhere in the blank blue light of Between. Time and logic faded away as he continued his struggles, gripping on to that fragile tether that would allow him back into his own skin. Normally it shone like a sunbeam, keeping him sure and steady, but this time, the road home was a dead, blackened thing. It was like trying to hold onto smoke, empty and vacuous. Tendrils caught in his throat, choking him as thick smog closed around him like a shroud.

After what seemed like centuries, he forced his eyes open to be greeted with the blank white plaster of his own bedroom ceiling. It was so mundane it seemed almost obscene, and Sherlock dragged in a shaky, pained breath as he tried to focus on his surroundings.

The click of a gun punctuated the peace, and he froze. A sideways glance brought John into his line of sight, sitting at his bedside with the blunt, baleful eye of the Browning's muzzle pointed at Sherlock's head. The pistol didn't waver, and John's face, pale and taut with strain but living still, wore the shuttered, horrified look of a man who would do what he had to regardless of the consequences to himself.

'Who are you?'

The demand was quiet but steel-hard to the core, and Sherlock revelled in a distant glimmer of triumph. Moriarty had forbidden him to speak of the deal, and that restriction lay heavy upon him. It was obvious in the stiffness of his jaw and the burden of his tongue: unspeakable. However, for all his seemingly benign nature, John was not an idiot. No doubt he could guess what Sherlock had done and who he had summoned to help him achieve it.

'Sherlock Holmes,' he replied at last, wincing at the sound of his voice. It was a husk of its former self, weak and rasping as if he had cried himself hoarse – just one of the many ills his weary body was beginning to report. He was bruised and battered in a skin that did not seem to fit. His sense of self, of where he began and came to an end, had lost its accuracy. The world felt as if it were sliding in place, no longer truly connected to him and somehow not quite within his reach.

Then there was his mind. Gone was the sharpness and focus. Instead, every thought had turned to tar, slow and ungainly in his head. Each moment was a battle in an ongoing war, and all the while he could senseMoriarty prowling at the periphery of his existence, waiting to strike and claim his place.

'Prove it.'

An impossible request. Perhaps John did not realise it, but any demon who could wake up in Sherlock's skin would have everything – his memories, his mannerisms, his voice – and could use them at will if they chose to do so. Nothing would be safe. He could only stare at John, trying to ignore the brutal weapon still aimed at him and force his exhausted mind to observe.

There was not much to see. Any evidence of the wound was gone, and the man who kept watch over him was firm and unflinching. A gleam of despair lingered in that blue gaze, clouding John's eyes and making him seem ten years older than Sherlock remembered, but that was the only outward sign of emotion. Everything else was wiped clean: a soldier's face.

Tentatively, he moved, stretching out one hand like someone reaching out to an animal that was likely to bite. John's grip tightened on the gun, but he did not back away or give any kind of warning as Sherlock's fingers brushed lightly over the place where the bullet hole had been.

He was wearing a different jumper now, a blank canvas that hid any sign that anything had ever been amiss, but the image was emblazoned across Sherlock's mind, hideously visceral amidst the haze of his other thoughts. Beneath his fingertips, like the sound of a distant drum, was the steady, solid thud of John's pulse. For all his trickery, Moriarty had kept his side of the bargain. John lived, and Sherlock was left like this – feeling as if he no longer belonged in his body and fighting every second to keep control from falling into Moriarty's hands.

'Are you all right?' he asked, pulling back his hand and meeting John's gaze. 'I thought – I thought I might have run out of time to get you back.'

John's expression crumpled, the shaky wall falling to let all of his emotion through. He looked wrecked, shaken up and broken down as he lowered the Browning. Those thin lips twitched downwards, twisting awkwardly as John clenched his jaw. 'You – you should have let me go. Why did you – How could you do this?'

'It was surprisingly easy,' Sherlock murmured by way of reply, wincing as he tried to prop himself up on his elbow and found his muscles uncooperative: it was like being the pilot in some machine, rather than a creature of autonomous reflex and instinctive movement. He had to think about everything, and his brain was overwhelmed by the unnatural effort. 'Do you honestly think I would let you die if I had any choice in the matter?'

'But this?' John gestured to him, meeting his gaze and flinching away, his eyes dropping to the floor. 'I know what you've done, Sherlock.' His voice cracked around that name, and Sherlock watched a tight, convulsive swallow flex John's throat. 'I wasn't worth crossing that line for –'

'And if the positions had been reversed?' he interrupted with a harsh bite. 'If I had been dying in front of you and you had the same ability, would you have turned your back on the option?'

He saw John's shudder, fear and horror at its most base, but beneath their wan glow was the answer Sherlock had already known. John would have done the same for him, had it been necessary. Their investment in their – friendship seemed too pallid a word, yet it would suffice – was equal and, it seemed, without limit, even now.

Good. Sherlock may have sacrificed his soul to Moriarty, but even in the heat of that uncertain moment, he had chosen his words with all the care he could muster. Moriarty would not have missed them. Sherlock suspected it was the wording, rather than the act itself, that the demon aimed to keep hidden by forbidding Sherlock to speak of it.

"My soul, such as it is and as long as you're able to keep it."

With that simple turn of phrase, he had left a potential escape route. If anyone could wrest his soul from Moriarty's grasp, then the demon would lose all claim to it, and Sherlock would be free once more.

He just needed someone who was willing to fight for him.

John stared at the man on the double bed, wishing desperately that he could rewind the entire day and start again. If only he had seen the damn sniper instead of remaining oblivious until the bullet hit his skin, because then Sherlock would still be himself, rather than this – whatever he was.

If he tried, he could almost pretend Sherlock was no different, but after almost a year of living with the man, some of his skills had rubbed off on John. He had no choice but to observe all the little, subtle wrongs. Worse, he knew what they meant. All the soulless John had ever seen had been more like automatons, going through life as if by rote with no real connection to the world. Sherlock was more present than that, but the disconnect was apparent in the way he moved and spoke – as if both actions and words took all of his considerable concentration and effort, rather than coming to him naturally.

Then there were his eyes. John had hoped that, once Sherlock came around, the mismatched colours would be gone. Yet the disparity lingered: one iris like a misty winter sky, pale blue and grey, the other the colour of muddy tar, bottomless and corrupt. The man in front of him might look and sound like Sherlock, might be Sherlock, but at any moment that could change, and he would be left with something else in his best friend's skin.

His best friend, who had sacrificed the thing he valued most to save John's life.

He should be grateful. A voice in his head spat that he should be on his knees, rapturous with thankfulness, because it was Sherlock who had saved him – not some paramedic doing their job without any risk of personal cost. Sherlock, who delighted in his own sociopathic persona, had blown that whole façade to pieces through the simple act of self-sacrifice, and he would have to live with the consequences.

If he wanted to, John was able to turn and walk away, his life intact. He could move out of London, carry on with his existence and forget the price that had been paid. Sherlock couldn't. His choice and actions would haunt his footsteps for the rest of his life, and beyond, if you believed the importance most major religions ascribed to the soul.

All for John.

'Thank you.' John winced at his own voice, finally setting down the Browning. He wasn't sure what good shooting a demon would do anyway. Would it really hurt anything but Sherlock? 'I wish you hadn't done it, but thank you. You saved my life.'

'For purely selfish reasons, I assure you,' Sherlock retorted, and in those words, at least, he sounded like himself. 'I've become used to having you around.' Licking his lips, he dragged himself into a sitting position and wobbled as if dizzy. He blinked, pressing a hand to his forehead before moving his fingers down to pinch the bridge of his nose. 'Why are we back at Baker Street? You should be in hospital. You were shot.'

'There's nothing wrong with me,' John replied. 'Nothing more than a ruined jumper and shirt, anyway. I wanted to take you to UCLH, but Mycroft wouldn't hear of it. He said there was nothing medical staff could do for you.'

'He's right.' Sherlock looked towards the closed bedroom door. He seemed bleary and confused, as if a familiar world was no longer making any sense to him, and John's heart clenched to see that acuity so dimmed. 'Is he still here?'

'Yeah, along with Greg.' John shrugged, getting to his feet as Sherlock slid off the mattress. He was as wobbly as a new-born foal, and John reached out without thinking, grabbing his forearm to steady him. He was not sure what he expected, a zombie, perhaps, something feigning life. However, Sherlock was warm under his jacket, and John could just make out the fretful thrum of a pulse beneath his fingertips.

Quickly, he let go again, watching Sherlock head for the door, limping slightly and moving as if his bones and muscles did not want to obey. He wanted to ask if Sherlock was all right, but that seemed like the world's stupidest question, so he groped for an explanation instead, filling him in on the facts.

'The police turned up not long after I came round. Your brother took the whole thing out of their jurisdiction.'

'Lestrade doesn't like giving up his cases.'

'He doesn't like giving up on you,' John corrected, watching Sherlock hesitate with his hand on the doorknob, face half-turned back in acknowledgement. 'No-one does. You could have been locked up in level ten containment; instead we brought you back here. Greg's not an idiot. He'll suspect what you did as much as me and Mycroft, but he didn't stop your brother from bringing you home.'

'Neither did you,' Sherlock murmured, dragging in a deep breath and bracing his shoulders like a man about to walk onto a battlefield. John did not miss the faint wince that tightened his features as he did so, nor the brief, fluttering tremor that raked down his spine before he pulled open the door and stepped across the threshold.

Mycroft and Lestrade had been talking quietly, and John saw their faces: the tight, grim masks of two men torn between the duty of their office and their regard for Sherlock. Greg's hands were on his hips, his head bowed and his lips pressed into a thin line, while Mycroft stood with his back straight and his shoulders hard, his knuckles gripped around the handle of the umbrella.

They both looked over as Sherlock stepped into the room, and now there was a divergence in expression. Greg's hazed over with uncertainty, confusion, and something like grief: all feelings that were mirrored in John. Mycroft's, on the other hand, grew sharper, his gaze deeper and more focussed as he took in his brother's presence.

'Interesting,' Mycroft murmured, and John fought not to bridle at the single word statement. Trust a Holmes to treat this whole mess like an experiment, rather than a disaster. 'You're still in control.'

'For now.' The warning in Sherlock's tone was as clear as day, and John watched his friend sag onto the sofa as if he did not have the strength to stand. 'I don't know how long that will last.'

'What can you tell me?' Mycroft asked, striding closer and towering over Sherlock. He was tense with urgency, and even John could see the desperation in Mycroft's face. 'I need details, Sherlock. I need to know if I'm to help you.'

Sherlock's throat pulsed, but no words came forward, and John saw Sherlock's jaw clench so tight he could hear the grind of his teeth in the quiet room. Creamy skin blanched out to pale white, and a spasm of pain crossed Sherlock's face before he simply shook his head.

Mycroft sagged, his fingers fluttering to press between his eyebrows. 'You fool. Can you communicate anything of the contract you made? Write it down, blink it in Morse code – anything?'

Again, that same negative motion, taut and agonised, as if Sherlock's spine were a bar of steel rather than a sinuous, flexible column of bone and tendons. It made John want to reach out and stroke his nape in an effort to banish whatever restricted Sherlock with such success, but he knew it was hopeless. This was nothing that a human touch could cure, and he doubted his meagre magic could make a dent in the power that had to be at work to exercise this level of control over Sherlock.

'I see,' Mycroft murmured, bowing his head as if all the options that remained open to him were ones that he could not consider.

'But you fail to observe,' Sherlock challenged, his baritone voice startling after his forced silence. He did not say anything else, but the look he gave his older brother was layered with meaning and rich with implication. It was the same stare John got more often than not, the one that told him he had missed something obvious.

A wrinkle appeared on Mycroft's brow, the only sign of his perplexity before, abruptly, it was smoothed away. The older Holmes lifted his chin, one eyebrow arched in delicate surprise as he breathed out a sigh of relief. 'I think perhaps I understand.'

Sherlock clenched his hands in front of him, glancing sideways before speaking. This time, it was slow and cautious, as if he were waiting for the bite of retribution. 'John being shot was not a random event. The gunman was a demon, one under the command of –' He stopped abruptly, a faint snarl catching in his throat before he tried again. 'The cult was to bring the sniper into our world, a weaker demon, not the Other One. They did not have the strength to attempt that.'

'Another demon?' Mycroft nodded. 'An agent. The stronger creature hurt John via this gunman, which brought you to him. A deliberate act, rather than one of chance. It seems –'

'Be careful what you say,' Sherlock interrupted sharply. 'I don't think –' A choked sound caught in his throat, and this time he rolled his eyes, looking more frustrated than uncomfortable as he sought out alternative words. 'I don't think the Other One can hear you now, but if it gains control of me, it will probably have full access to my memories. The less information it can derive, the better.'

With a brief nod, Mycroft gestured for John to follow him, murmuring for Greg to keep an eye on Sherlock and call if anything untoward occurred.

The last thing John wanted to do was leave Sherlock alone. Somehow he felt that the act of watching him was enough to keep him here. The fear that, the moment he looked away, the demon would gain the upper-hand sat like barbed wire in his throat, sharp and aching.

Reluctantly, he followed Mycroft down the stairs and out of the front door, bracing himself against the chill as they stopped on the doorstep.

'What's going on?' he asked, not wasting a moment as he thrust his hands in his pockets and glanced back up at the lit windows of Baker Street. 'What did Sherlock mean? Why couldn't he speak?'

Mycroft pursed his lips, looking thoughtful before he replied. 'Sherlock's inability to discuss any of the details of his covenant, or even speak the name of the demon with whom he agreed the contract, is surprisingly informative.' He stared unseeingly along the street, his eyes unfocussed. 'The demon has forbidden him to enlighten anyone of the details, which means there is something there worth keeping hidden. It is clear that Sherlock did not have the time to form a water-tight agreement, but neither did the demon. It could work to Sherlock's advantage.'

John shook his head, too exhausted and torn by the day's events to unravel what Mycroft was talking about. 'How?'

'While Sherlock may have surrendered his soul, qualities such as obedience or loyalty may not have been specified.' Mycroft's lips curved in a fractional smile as he clarified, 'Sherlock can do exactly what he is doing now, and fight. Until the moment his soul is devoured, he will be able to offer resistance.'

'And how long will it be before the demon decides he's too much trouble?'

'He must be worth more to the creature in question than mere sustenance. That much is suggested by the fact that the demon orchestrated your murder in the hopes that Sherlock would act exactly as he did.' Mycroft narrowed his eyes, his umbrella tapping out an absent rhythm against the pavement. 'The question is, what does he want it for?'

'No,' John snapped. 'The question is, how do we get Sherlock out of this mess?' He crossed his arms, straightening his shoulders as he glared at the man in front of him. 'This isn't an experiment. It's your brother stuck in some monster's power –'

'Because of you,' Mycroft interrupted sharply, effectively silencing John with a leaden rush of guilt. When he spoke again, it was softer, though far from apologetic. 'In all the years I have known Sherlock, he has never shown regard for anyone. I wonder if you comprehend the significance of his actions?'

'He saved my life,' John whispered at last. 'Of course I understand.'

'No, I don't think you do.' Sadness lingered at the edges of those words, but it was gone before John could question it. 'At least not yet.' Mycroft fiddled with his umbrella, taking a deep breath of the cold night air before gracefully changing the subject. 'I need to do some research. What Sherlock did today may have been a rash and foolhardy choice, but it is also impressive, in its way. That he has the strength to keep a demon of such calibre at bay and fight the – albeit loose – constraints of the deal is frankly unheard of. I need to know more.'

'So we can get Sherlock back?' John asked, hearing the fragile hope in his own words and hating their weakness.

Mycroft's gaze took on a pitying gleam before he looked away. 'So we can prepare for any eventuality, Doctor Watson. A surveillance team is in place, and I have left a panic button device in the flat. Should you require assistance, press it, and help will be with you within two minutes. Sherlock is to be considered under house arrest. It is the preferable alternative.'

'As opposed to containment? Is that the best idea? I mean, I don't want to see Sherlock locked up, but if the demon takes over...'

'If he gains control and finds himself so tightly constrained, what do you think he will do to Sherlock as a result?' Mycroft asked. 'My brother is not merely a potential carrier for this creature, he is effectively its hostage. Please make sure that Detective Inspector Lestrade is also aware of that interpretation. He is more the victim in this scenario than the perpetrator. I will explore the demon's capabilities. The more we know, the better.'

'What about me?' John asked. 'What do you expect me to do?'

Mycroft gave him a weary smile. 'The same thing you have always done. Take good care of my brother, John, and be careful. I'll be in touch.'

With a nod of farewell, Mycroft departed, striding towards the black car that waited nearby and leaving John to turn back to the familiar door of Baker Street.

His body moved with heavy lethargy as he pushed his way inside and climbed the stairs, trying to breathe around the helpless, hopeless weight that had taken up residence beneath his ribs. The enormity of what Sherlock had done for him plagued his mind, becoming the centre of gravity around which every thought circled. It was too much to grasp, but he tried anyway, repeating the facts to himself as he reached the top of the stairs and nudged his way into the flat.

He was alive, and it was Sherlock who had paid the price. That was not the kind of sacrifice John could ignore. He had been fascinated by Sherlock from the moment he had met him, caught up and carried along in the whirlwind of their existence, and he was not about to let some stupid demon turn all of Sherlock's potential into a mindless vessel. He was fighting, and John had every intention of being at his side until the end.

Wherever the battle took them, they'd go there together.