Snake in the Grass

Disclaimer: Sherlock and its characters belong to the BBC and Arthur Conan Doyle - just the Shift concept belongs to me

This is the start of the sequel to 'Shifts' - you may want to read that one-shot before this; don't worry it won't take long

Now from the start of this I promise it's not a repeat of an episode - the plot and concepts around it are completely different; trust me.

And thank you so much for all those who have read, favourited or reviewed 'Shifts' - it all means so much to me and I love you all for it!

Enjoy x

"There is nothing more deceptive than an obvious fact."
― Arthur Conan Doyle, The Boscombe Valley Mystery

The Present

The clear darkness of the sky highlighted the full moon; the beams shadowing the sleeping buildings whilst revealing the hidden pockets on the street corners and in the covered alleyways, leaving the hours deprived of secrets and horrors for that one moment.

John basked in these minutes of tranquillity when they came about; perhaps it was the hound that enjoyed the feel of the night air on his skin, the vast openness of the city with an unstoppable amount of roads and routes to sprint down and the sense of freedom from being in a place where nobody was present to throw second glances at the bulky beast of the Shift.

Or maybe it was the human part of his brain that fascinated in the fact that he was currently being lit by the light of the sun despite it lying at the opposite side of the world, the thought that he was witnessing balls of gas light-years in the distance from an insignificant pavement in an area that was a dot in accordance to the universe and the idea that among the millions of people that swirled around him only he was awake.

Either way he was enjoying his silent walk through London's streets, after the events that had begun to unfold over them in the past week it was a relief to have a small break from the live recordings on the pink I-Phone and the sometimes inhumane glee the eccentric detective flashed as they ran around trying to piece together the string of riddles.

Sherlock was undeniably the genius of the country and the one option for a clear-cut, quick answer to a case but unfortunately for him the average majority of crimes were committed by fellow Shifts, meaning that they all fell in his 'boring' category.

"The world understands that there are a large number of people who can turn into animals! Is it too much to ask them to be more original in their murders rather than simply clawing, pecking or mauling a victim! Where is the challenge in that? Are all Shifts really so densely idiotic!"

Along with the simplicity route that went with these crimes there was also the fact that the detective could identify a Shift as soon as they entered for an interview or were caught after a chase due to the aura that could be detected.

"You know if a suspect's a Shift at the exact moment I do! Think of the insult that is to my mind - why do cases that your average brain could solve a mere minutes after mine deserve to be even hinted in my direction!"

So actually listening to one of the detective's self-important rants for once, Scotland Yard formed a Shift division purposely for crimes that had such suspects; it seemed even Lestrade had agreed that if there were others who could carry out the same job without the sociopathic attitude it would be a relief for all.

Which of course meant that from that day Sherlock had automatically shunned any case that included anything around the Shift heritage; which hadn't left many openings for the detective's ever-working brain seeing as most normal beings felt that they didn't have enough power to accomplish the feats of the Shift criminal world.

So the sudden appearance of the human crime-genius Moriarty had been a blessing to the quick maddening feline; the new criminal wasn't on any Shift registers plus from the utterly non-Shift route he was using it was clear that the man had no link to the heritage. So Sherlock had thrown himself into the task, urgently awaiting each new message as soon as he finished the previous; John had forgotten what their wallpaper looked like, it had been re-plastered with a vast collection of maps, theories and strangely a portrait of Elvis Presley.

Four messages so far, each one following the same format but with different subjects. There been a mid-aged woman, a late twenties man, an elderly woman and a young child; Sherlock had already stated that they were simply pawns in the game and didn't hold a connection to Moriarty's route or desire so were unimportant. Though John had alternative opinions on the matter of innocent people's lives when it was brought up which had resulted in the detective's dressing gown parading a few new claw tears; but it hadn't changed the fact that Sherlock was correct about the victims being randomly picked.

Each message was a live video sent through a pink I-Phone, it would show a paralysed victim set in an empty room in an unknown destination with a countdown placed next to them. The instructions or pictures would be shown on the screen leaving the two Shifts to find the answer to Moriarty's shoe snapshot or short sentence whilst having the image of dying citizen sitting in their pocket.

Sherlock had deduced that the victims were being injected with some form of poison from the first message, which easily explained why the time limit given for each 'pip' varied as it depended on the volume of poison that had been administrated. The detective couldn't tell what the poison was from the medium-panned video and without a list of symptoms; so deleted the victims once they had been taken to the hospital as he found it a waste of time to go and wait for their minds to become clear enough to explain their drug encounter. So far most cases had received the antidote in time and were now recovering safely in hospital, doubled checked by the concerned member of 221B; most except the third pip.

It had been a meaningless death; all the others had been knocked unconscious before waking in an unfamiliar location but the precaution had obviously been deemed unnecessary for one lacking the ability to see. Though this meant she had heard; the woman had listened to a brief mutter from Moriarty and she'd tried to describe the sound to Sherlock despite desperate protests, but the live feed had suddenly cut off as soon as she began and she was found dead with a second injection prick millimetres from the first.

John sighed, running a hand through his hair; now they were just waiting for that final message and the suspense was killing the Shift; he could just imagine a care-free person quietly sleeping in their bed as he walked the streets, not knowing that soon they would be bundled off and drugged all just to satisfy the needs of a manic criminal.

Suddenly the hairs on the back of his neck straightened and he froze, his muscles tensing and his eyes sweeping the area; something was wrong.

A faint rustle only picked up by his canine hearing sounded from behind and he spun around, his body already hunching over as it prepared to alter its form; but a dark shape rapidly lurched from the bushes before the hound could appear and the Shift cried out as a sharp pain stabbed his neck before a blunt object hammered against his skull and the darkness flooded his sight, taking the tingling sensation in his flesh with it.

Sherlock cautiously sulked down the dimly lit corridor, his black fur mingling with the shadows as his green eyes flicked over every supposedly locked door; the main ones leading to the pool having clearly already been unlocked from the slightly fainter reflection of light bouncing off the lock where a hand had recently been placed while opening it in preparation for his arrival.

Gratifying to see some common courtesy intact, he'd been expecting Moriarty to be in place for the meeting, leaving it to look like Sherlock was the one whose presence had been requested rather than the other way around, criminals do enjoy their power-plays.

The memory-stick holding the missile plans dangled between his teeth, it would be easier to simply carry them in his human form but when dealing with a non-Shift criminal such as Moriarty he was wary of the fact that quite a few snipers were probably placed around the area due to that need to show strength to a Shift through human means, and a feline made a much smaller target.

Bending his hind legs and lowering his back Sherlock briefly eyed the metal push bar, calculating the level of force he'd have to place on it in accordance to his lower mass before taking a well-aimed leap and pushing the bar down as he landed on it, causing the door to jolt open enough to let the feline jump into the room as the metal entrance slammed behind him.

The stench of chlorine hit his sensitive nose straight away and he took effort to hold back a hiss, but as the pungent smell relaxed through familiarity another recognisable scent became clear and Sherlock's back arched with his hair standing on end – John!

Snapping his head around his gaze fell on his friend jerking around on the floor, one of his hands grasping a changing-curtain with whitened knuckles as he clearly tried to smother down his desire to cry out.

Sherlock's eyes widened at the sight and with perfectionist skill he shifted mid-sprint without losing any momentum and fell to his knees at John's side.

"John describe your symptoms to me!" The detective barked; he assumed that the doctor's state was due to the injection that had been used on each person so far, but until now they had never witnessed the victims before the stage that left them paralysed and that, plus his refusal to visit any of the previously poisoned meant he was unaware of the concoction that had been used, never leave loose ends!

The lack of an understandable reply sent a shot of panic through his body and his nerves slipped through his tone as he ordered again, "Your symptoms Captain!"

The poisoned Shift's chest was bursting at the rim; it was as if a sumo-wrestler was lounging on him, he could barely control his arms and legs and his attempts resulted in exaggerated flailing. He could taste the blood in his mouth from where he'd ripped through his bottom lip as he tried to resist his need to scream, not wanting to give any satisfaction to Moriarty who was likely somewhere near-by watching the event and he could feel the tears stinging at the corner of his eyes from the embarrassment of the puddle of urine beneath him as his body had lost its bodily functions.

Hearing the familiar voice John's eyes snapped open and he took in the uncharacteristic plaster of fear on the detective's face, but the sound of his title shook him into focus and he tightly relayed through gritted teeth, "It was in the neck – blow to head mixes timings… but – from consciousness - tingling sensation spread from the region across the body after six minutes… eight minutes increased salivation – twelve drowsiness…"

He let out a strangled gasp as the pounding in his chest hardened, "Fifth-teen degrading co-ordination… twenty loss of bodily functions and now… now bloomin' great chest pains – "

A pained grunt broke off his analysis and he pulled at the curtain clenched in his fist, his strength causing it to rip from the bar so he drew it to his screaming body, curling himself around the material as the torture sliced through him.

Sherlock's mind was reeling through the information, comparing the rough timings of symptoms and the likely time of full paralysation in accordance to the timings between the appearances of each new victim next to his mental library of poisons whilst trying to block out John's shaky gasps.

The soundest conclusion would be neurotoxic venom…

As the thought came to him a whole new pathway opened up and his eyes widened at his own stupidity for not thoroughly checking over the victims attacks; his fingers quickly moved to John's collar and he dragged it down, inwardly cursing at the marking on his neck.

The two small puncture wounds sitting approximately two centimetres apart were highlighted by the purple swelling skin around the area, showing clearly a venomous injection not through a needle, but by a snake.

"The Black Mamba…" Sherlock whispered, unable to completely douse the spark of delight at the situation suddenly becoming a lot more interesting.

"So that's how you've been obtaining the victims," The detective theorized, raising his voice to address the room as he slowly got to his feet and scanned the area for signs of movement; making sure he kept his body positioned in-line of any potential shooting points towards John, "You've been using a Shift to do the dirty work – not that I'm surprised by your need to use another hand on the capturing front but I'm curious as to why a normal human of the criminal nature would associate with one of the heritage; isn't there a raging battle for dominance of the underworld between your kinds?"

The pool remained silent, which was seen as a sign for the detective to continue talking, "One bite and they'd be easy to take, next just let the venom reside until the victim was rendered speechless and immobile so they couldn't form hints over video while they were kept as pawns and then finally they would be left in a catatonic state even after having the anti-venom injected leaving you free to continue this game without revealing your advantage."

His smug tone echoed off the cold walls and Sherlock took pride from the lack of response, seeing it as proof that he had taken the upper hand.

A cracked wheeze brought back the realisation that there was more at stake than the case at that moment and Sherlock quickly risked a glance behind to note that John had fallen into paralysation, his normally assertive eyes hollow and glazed as his body began to shut down.

"Look I have the plans!" Sherlock announced, worry evident in his voice, "That's what this has all been about and here, you get it – just hand me the cure in return."

A slow echo of dripping water bounced off the walls as the void of response continued, but then, as if the noise was climbing up through the cracks in the floor a deep chuckle emitted across the pool.

"Oh how precious is this," a childish whine called out, "And to think if only you'd used my number we could have gone out for a coffee – and then you wouldn't be as averagely dim as you are right now…"

The end of the spitting sentence came with the sharp click of footsteps as the sight of a face that wasn't completely a stranger came into view – along with the fact that this face came with an aura that distinctly characterized him as a Shift.

For the first time in his existence; Sherlock's brain actually froze for a millisecond. Just as quickly it jumped back into action trying to find even a hint of reasoning as to how the event had suddenly switched in such a way.

"But that's not possible…" The detective whispered, mostly to himself, "You came into the lab with Molly – and you had no aura of Shift; how could you possibly have one now?"

Moriarty, or Jim as he now apparently was, flicked a smug grin with an exaggerated shrug, "Well everyone has secrets don't they; I just happened to find a way to keep mine a secret from everyone… dull Shifts and humans alike."

Despite the situation, Sherlock's eyes had an alit spark in them as he assessed Moriarty and the new evidence that he was a Shift and had somehow managed to find a way to hide the fact from even those who shared the heritage and could sense all the others of their kind; it was like a triple homicide at Christmas!

"So you've created a form of… chemical most likely – that manages to make the Shift gene regress so that it fails to give off the heritage aura," The feline theorized, clasping his hands behind his back and retaining an uninterested mask over his features to insure Moriarty wouldn't be aware how impressed he actually was.

"That's me!" The clearly unstable man sang, skipping a few feet closer to the detective before sliding a small tube of lilac liquid from his trouser pocket.

"This little thing is just so ingenious; not even you can disagree with that darling," Jim stated, waving the tube in-front of him in the way one would to bait a pet.

"Without analysis it could just as easily be a tube of coloured water and our first meeting just happened to coincide with a flux of my aura senses," He replied in a dry tone.

A flash of anger broke through Jim's child-like glee but he quickly recovered it with a humourless smile and shoved his hand in his Westwood jacket, chucking the detective a brown envelope, "Well there's your evidence science boy."

Sherlock refrained from smirking as he received the envelope he had guessed would be on Moriarty's person, not trusting anyone else including computers to look after his invention; it would save him a lot of time from where he would have had to study the liquid through numerous tests.

He simply flipped open the paper flap and glanced at the documents; he didn't doubt that Moriarty had created this gene numbing chemical but the details weren't high on priority at the very moment.

Sherlock allowed himself a second to spare a look to his fallen comrade; logically he knew that he was fine, all the other victims had been left in the paralysis state for much longer periods than John was currently ticking through. Although despite the known fact of his safety, for some strange reason the detective still felt a sense of… worry.

"Well then, seeing as your intentions clearly weren't to do with obtaining the missile plans but were instead about being able to show off your new chemical to someone else with an intellect that would value the complicity of it all; I'd like to be taking that anti-venom with me now."

The criminal raised a finger to lightly tap on his chin and lightly shook his head, mocking disappointment seeping into his tone, "Aren't you even going to say thank-you for your present?"

Sherlock's gaze hardened for a second as his brain rushed to tell him the meaning of the Shift's question and his eye's widened as the result came through, "Oh… you've already released this chemical throughout your web; right now every criminal, petty or serious, will be buying and taking your new product."

Jim threw on an excited grin but his head slowly tilted from side to side, giving a predatory feel to his words, "Every Shift who's been limited by that pesky heritage connection of being able to sense each-others auras; it won't matter anymore. Take one injection before each escapade, police interview or chase and nobody will be any the wiser about your little problem; feel free to blame your crimes on those normal humans – it'll be the most excitement they'll get in those boring lives of theirs."

"So this is what? You giving me a warning?" Sherlock replied, raising an eyebrow in amusement at the notation.

"Nope," He answered, popping the last syllable, "Just a bit of entertainment."

Then chucking a full syringe at the detective he casually spun around and walked from the room; hands in his pockets and gently whistling the tune to 'Staying Alive' by the Bee Gees.

As soon as the click of the far door sounded as it swung to a close, Sherlock fell to his knees and grabbed John's limp arm, quickly forcing up his jacket sleeve and stabbing the needle into his skin; injecting the anti-venom into his bloodstream.

He watched his friend with wide eyes, scanning his face for signs of response. His mind was tracking the anti-venom through a mental biological map so he knew at what point John should begin to show flickers of consciousness yet he kept re-checking himself; what if his calculations were wrong? What if another unknown variable had been put in place and ruined the whole antidote?

But as the doubts started to enter his mind the Shift let out a low groan of pain, soon followed by slow movements of his hands and legs to check that they were once again under his control.

"John?" The detective prodded, unsure of if there was some form of sentence he was expected to use after this kind of situation.

"Yeah… I'm fine," John muttered, shakily lifting himself from his lying position using the detective's arm which had been held out as he'd began to move.

"Good," He responded, carefully positioning the Shift so he was leant against the wall, "Good."

Sensing that Sherlock was having trouble with the anxiety that he was feeling and the fact that he didn't know what to do with the emotions, John helped him along and swiftly changed the subject away from his poisoning.

"So – your present?"

The detective's furrowed features suddenly lit up once more and he swiped the brown envelope from behind him and settled into a cross-legged position in-front of the pale doctor.

"It's quite ingenious," Sherlock began, taking the collection of documents from the holder and expertly scanning over them, absorbing the information double the speed of any normal person, "The whole basis is around the fact that as Shifts we are driven by human and animal nature; meaning our emotions work on a much more animalistic level than normal beings."

"Makes sense," John mumbled, his eyes drifting shut as his body begged for rest yet his brain knowing that that wasn't going to become an option until Sherlock had finished his talk.

"Of course it does. It's a simple observation; canines will wag their tails when experiencing a positive emotion, felines will arch up and hiss when they feel they're in danger. But this chemical works on the track of survival instinct – normal humans have it; but in animals it's just that much stronger."

The scientist side of the Shift was fully shining through as he continued to dissect the information in his hands; seemingly forgetting John was even present, "Oh that's good – biologically fear is a warning signal that death, injury or destruction is imminent; relate that to animals and you're looking at the instinct of fleeing when the brain receives that chemical classified as fear. Seeing that the Shift gene reacts on a pure instinctive basis being the core of the animal qualities – eject the correct volume of a solution containing obvious pathogens, just enough for the body to recognise the attack but just too few so that they can quickly be neutralised by the immunity system; the Shift gene senses the danger, retreats in on itself causing the aura it usually casts out to be dragged back in until the threat has past!"

Jumping onto his feet, Sherlock let out a laugh, shaking his head, "Oh why didn't I think of this sooner! I could have had a proper case months ago!"

Flicking the paper through his fingers the detective headed for the door, speedily muttering equations and chemicals under his breath when a stern cough interrupted him.

"Sherlock!"

Turning to his name a flood of realisation came over his features and he quickly ran back to the Shift he had left sitting in pain on the floor, "Oh, sorry! It's just so fascinating!"

John groaned as he was gently helped off the floor and he winced as his legs took the full weight of his body, "Yeah… obviously."

Swinging the doctor's arm around his shoulder and placing his other hand around his waist, Sherlock was forced to awkwardly bend over for his friend's lack of height as he guided him towards the exit; though it still didn't stop his ramblings, "But the question is why would Moriarty go to all the trouble of creating the chemical in order for secrecy when he was simply planning to tell me about the whole thing once it was completed?"

His head lolling forward as fatigue began to win over him, John's words came out as a low slur, "Maybe he gets bored too…"

As if just remembering that the man he was practically carrying had only just return from paralysation after a snake bite, the detective cast him a worried glance; his tone falling into an uncomfortable territory, "How – um, how are you doing?"

John gave a weak chuckle at Sherlock's attempt of comfort but appreciated the gesture, "I've seen worse – just get me to a bed."

The detective's brow furrowed as he tried to bring across his sentiment, these things were always so much easier when John was a hound, "Um – yes well… I'm glad you're – you know…"

"Thanks," John gratefully replied to Sherlock's version of, I'm glad you didn't die.

"Well," He continued, smoothly moving away from the sincere moment, "You can sleep tonight, but by the morning there should be no traces of the venom in your blood and all swelling and bruising should have gone down – we're going to have a lot of work on our hands if we want to keep on top of the sudden rise in criminal activity starting tomorrow."

As the metal pool door swung shut the flat tone of the battered Shift was left echoing through the empty room, "Oh joy."

6 months later…

Shots cracked through the air, bursts of dry soil flying across the horizon; taking material and injured with them which landed with defending crashes only to be followed by further explosions.

Two men scrambled over their fallen comrades with forced disinterest, lifting their guns over their heads in weak attempts to shield themselves from the grenade debris. Screams rung through the Afgan valley as more timed mines were activated and further snipers were released on the area; one of the men drastically lunged to his left just missing the hand-grenade that destroyed the ground he'd been standing on moments ago.

Shrill ringing piercing his ears he only felt a hand clasp his arm and drag him forwards, his eyes seeing his friend's mouth move but his ears failing to tell him the noises that were coming with it.

"Target less than fifth-teen metres ahead! Don't slack on me now!" Seth Manning barked at the last remaining man of his unit, giving him a shove in the right direction Seth continued on the trigger-happy trail, sensing that Bryan was following.

It was the pain-in-the-neck criminal warfare dealer who they had been tracking for capture and recover for who knows who could remember how long. A couple of months ago the man had suddenly appeared in his main trading ground; from stupidity or clear arrogance it couldn't be told.

None of the force, even the higher intelligence knew much about him; there wasn't even a name available to go with the crimes. All of his customers who they'd extracted information from had simply referred to him as 'the dealer'; but what was known was that he had control of every single weapon or ammunition that left or entered the country – some people actually had suspicions that the army itself would sometimes obtain machinery through him when they were in dire need.

Then a few days ago a source had reported the man's entry into the local area; actions had been taken into effect immediately and a high status track and retrieval team was released with orders to capture preferably alive – although only preferably.

Now only Captain Seth Manning and his comrade Bryan Lems were left, the other 15 men making up the original squad having been killed in action; most during the last ten minutes in the previously unknown high-wired valley which had been laced with mines, automatic snipers and remote controlled hand-grenade catapults.

It had looked like a panicked flee into the sharp valley on 'the dealers' behalf and the team had thought themselves to have the clear upper-hand; but the dry land had quickly become a blood bath and the stolen souls of his fellow soldiers was what was now spurring Seth on with a savage eye.

"Move man!" He barked, pushing Bryan ahead of him as he stumbled again; there was no way on earth that he was going to be the only man from the team going home, he needed his fellow soldier to stay alive.

Squinting through the thick dust Seth cursed as he realised he'd lost track of the dark figure that had cost so many lives; 'the dealer' had disappeared in the clouds of the ammunition.

Suddenly a massive explosion burst from his left and he was thrown to the ground, hearing Bryan's pained cry amongst the blasting noise.

Ringing in his ears Seth wildly looked around for his colleague through the dirt and debris; turning his head just in time to see the barrel of a gun and hear the crack of a shot.

A newly polished black leather Gucci shoe stepped off the small dust covered plane, slowly followed by the accompanying tailored suit and crisp-cut tie. The wearer of the outfit surveyed the run-down surroundings of the hidden landing zone through his tinted sunglasses before raising his head to the sight of the British sky; a satisfied smirk gracing his face.

"Um… I've been called for a Moriarty?" A nervous cab driver spoke up, if not already worried by having to drive to a non-existent airport with threats on his family for keeping his silence, definitely so now by the sight of this man who radiated the sense of pure danger.

Closing his eyes at the soft gaze of the sun, the man replied with a tone of content, "Get me to London."

A/N: Updates won't be amazingly regular I'm sorry because I'm really busy but I'll do my best!

Thank you, please review :)