Original Prompt is that John Watson is a serial killer. Everything else I just ran with.

Part two of my Serial Killer! John Watson Tumblr prompt. There will be a third part, which I'm already writing, that will wrap this all up. This was really fun to write, and I hope I get more prompts/find more prompts soon. Also, Thanks for all the reviews! They're much appreciated!

Den Of Lies

John had been in custody for little less than two months before he decided enough was enough and escaped, right out from under the careful watch of all of Scotland Yard and his brother. In that time, Sherlock had been denied even the briefest of contact with John while DI Lestrade and his Goon Squad relentlessly questioned him by day and his brother ruthlessly interrogated him by night. Yes, he was well aware that his brother was using under-handed methods to try and get John to talk, to tell them about the seemingly random kill pattern that he'd adopted, about his methods. A pattern that had claimed a few of Mycroft's lesser peons as it turned out, though they had been months, almost years apart, with no visible connection. It was the one request Sherlock had made of his brother in the wake of the arrest. It also infuriated his brother, Sherlock knew, and it rubbed all of the Yard the wrong way. His silence and John's turning.

Goody Two-Shoes Watson, they'd once mocked, but not now.

John was The Wolf.

And Sherlock felt like a proper Mutton meal.

Now the only looks John knew were ones dealt in hatred, sorrow, rage, horror, disgust, and confusion. Why would such a seemingly nice, honest man do something so utterly horrible, utterly sickening? Why would a man who'd taken the solemn oath to save and cure people turn his talents to harm instead of help? Because he was in fact the Doctor John Watson, he'd just covered his past trail with the ease and practice of a finely honed killer, and part of this cover up had involved the killing of his last remaining flesh and blood along with her spouse. But for whatever reason, the day he'd entered the army as well as met the great and infallible Sherlock Holmes, he'd used his real name. So clearly he wasn't ashamed of himself or his lineage, which only further stumped all of those investigating the deep and treacherous waters that made up John Watson. Because both of John's parents were dead.

So far the victim count was up well into the hundreds even without John having said anything, though Sherlock didn't think that all the cases they were attributing to John involved his hand. His beautiful and deadly touch, a flair of finesse was lacking in some of them, not that anyone but Sherlock seemed to care. Mycroft already seemed to know this as well, but he hardly cared, and was still working at John steadily, though the man in question hardly seemed any closer to cracking than he did when they'd taken him into custody. It was why he didn't say anything about the cases that were not of John's handy work. John was already going to prison -if not an asylum- for the rest of his life, why not give those few families the closure that they deserved, even if the mass murdering Wolf didn't do it?

That's what they were calling him now, what he'd been dubbed, the name he'd carved out of the world for himself. The Wolf...Sherlock thought it was very fitting. Especially since the man seemed to work best alone, though he could easily blend into larger crowds with ease and surprising patience. It is what made John such an efficient and deadly killer. It was also made him able to blend in so well, to conform to what people expected of him, able to pull the wool over everyone's eyes including him on. His persona was able to say 'No, I'm not a wolf, I'm a domesticated dog, Sherlock's domesticated dog, and I'm nothing more than a dumb mutt. See? Even he treats me like some worthless dog.' and no one questioned it. It also didn't help that The Wolf's favored form of killing involved a custom made knife, something Sherlock had never seen John use before. John had hidden in such plain sight that no one had suspected a thing.

Not even him.

So when John somehow just walked out of Scotland Yard without so much as a friendly off-out, he was the first person that everyone came too. Mycroft had upped his security when they'd originally arrested John, of course, but it was sort of a surprise to find the man himself upon his door step calling. Sherlock hadn't really left 221 B since the arrest, having no reason or motivation to really go out, the betrayal fresh and still throbbing deeply, as well as Lestrade's questioning gaze wherever he went. After the first few times he'd tried to leave to do something useful, something productive, and felt the shunning gazes of all of Scotland Yard he'd returned to his shared apartment alone. So desperately alone, and hadn't come out since. Mycroft had said nothing of his worldly absence as it made his surveillance job so much more simpler, but even he was starting to feel the strain of Sherlock's poorly-hidden pain.

Not long behind Mycroft was DI Lestrade, followed closely by Donovan and Anderson, both of whom had taken to simply glaring at him over the long months, and the rest of the Scooby Gang. He was still unsure if they felt hatred or pity towards him now, and was fine to let the questions go unasked. He didn't care what they thought anyways. What did they know of hidden betrayals? Nothing, and it was safe to leave it at that.

After a week of questioning him in the beginning, Lestrade had gave one final sigh and gave up, relinquishing the house arrest to Mycroft. The man's superiors were certain that Sherlock the sociopath had to have known what his wacko flatmate was doing in his spare time, but it was quickly becoming obvious that Sherlock hadn't a clue. He didn't know that those weren't normal dates that John adventured out onto whenever he got the chance, and why he was so upset with Sherlock when he was called away from them so rudely in the middle. It made Sherlock long for incarceration as well, if only for his stupidity, and that's why he'd settled on his own self-imposed exile. He wasn't technically on house arrest, not formally anyways, because they'd quickly deemed that he hadn't a clue to what John was doing while living with him or before their first encounter. Now it was just a form of describing Sherlock's reclusive behaviors, one that his brother didn't seem overly fond of but went with anyways. There was no talking any sense into him once he'd decided that enough was enough, and even Mycroft knew that. He had long ago decided to pick and chose his battles.

So Sherlock had wallowed in his own self-ignorance and hatred for a few weeks now, hardly leaving, hardly speaking. It was his own way to deal with all the grief, yes, but it was also a means of punishment along with a chance to try and see this all from the other angle. The darker angle. The one John Watson The Wolf had been lurking from for years now. He just hadn't been smart enough to see what was right in front of his eyes.

In the end, it had been James Moriarty's disappearance and death that was John's undoing, Sherlock knew. The actual act of the murder had been sloppy, so unlike the others, that it was hard to even put it together with the fine work that John normally did when someone finally stumbled across the remains. This one had been a crime of passion, fueled by pain and anger and true hatred, beastly in a true Wolf fashion. Sherlock thought it was the most beautiful of all of them, once he'd finally gotten his hands on his brother's case files and photos, because it showed just how animalistic John could truly be, though he'd never say it out loud. It was delicate and well formulated up until you got to the actual murder itself, each detail well versed and thought out, meticulously planned and formulated. (It was why Sherlock have never glanced twice at John, his own simple John.) But the method and means of death were the barbaric beauty that most artists and common place murders lacked, and it is what made Sherlock's heart region flare pain more than ever.

"Why Moriarty?" Sherlock had asked out loud then, knowing full well that he wasn't alone. His company knew it too, knew why his voice rasped from disuse. "Why not someone else, someone not so close to us? To you?"

"Moriarty was a threat, that's the only reason I went after him, in the beginning. It was why I searched for you, a way to either be rid of him through you or get close enough to take him out myself. You were my wool, Sherlock." John said calmly, the knife palmed in his hand with a familiarity that should worry Sherlock but strangely doesn't. It was curved and beautiful, just like the reports said it would be. "He would have muddied up the waters, so to speak, caused a commotion that would have drawn unwanted attention to me, my kind. I've been doing just fine without that bother, thank you."

"Yes, I am well aware. Your ease of movements is impressive, if nothing else." Sherlock said calmly, eyes level on John's languid form as it bled in and out of the shadows of the apartment, the flames flickering across his well-lined face. Sherlock hadn't left the window open. "You seem to continue on in your good fortune. He didn't stop you. Neither did my Brother or his goons."

John snorted, grinning madly as he stared down Sherlock.

"No, Moriarty just ratted me out." John sighed as he stepped further into the dim light and away from the window where the lightless street became a gaping black hole in the night. The Wolf had cut the power quite some time ago, a disguised power outage in the early winter working to his advantage. "He was a loud mouth, even in death. I shouldn't have left his body as a warning like I did. I should have hidden it like I did with most of the others."

He only glanced at his chair before sitting into it with a familiar practice, and suddenly Sherlock felt whole once more. Odd, that feeling of eagerness. It would one day be his undoing. Today was probably that day.

"Hmm." Sherlock could only shift slightly as he repositioned his crossed legs beneath him. "Perhaps you should have done away with him like you did Irene?"

"I'm sure even you were a bit surprised that it was me, and not you, that ended up putting the bodies where the Yard kept finding them though. The ones I wanted them to have, anyways." John sneered, though it wasn't meant in anger, more in hilarity at everyone's stupidity. At Sherlock's stupidity, which is the same reason he ignored the Irene jab. "They were certainly surprised. I wish you could have seen the looks on Anderson and Donovan's faces. It was sublime, Sherlock. You would have loved it."

"Is this how it ends, John?" Sherlock asked suddenly, ignoring the taunts John kept laying out for him, the silent stabbing at Sherlock's conscious that kept repeating his failures in the same way that it reminded him keenly of the knife still clutched in John's left hand. "Are you to slit my throat as a way of tying up loose ends? Stab me during your little black out and run off into the night like some common thief?"

"But I'm not some common thief, am I Sherlock? Not that you'd know, you thought me dull, dim like the rest of the lot. But I'm not stupid, Sherlock." John seethed, his tone and anger as tightly controlled as ever. John was in control, he probably always had been. "I'm going to end this tonight. I'm tired and your brother would have me put down either way. Might as well go out fighting as opposed to chained to a wall in a dark cell, wondering where it will come from."

"Then you mean to go too?" Sherlock wasn't surprised, that this was John's End Game, and he'd come to ask Sherlock along with him. It was sort of sweet, really. Compassionate. "I'd have never thought you the type to give up so easily."

"Together, Sherlock. I promised you, didn't I? That I'd never leave your side." John smiled a tiny smile in Sherlock's direction, his words ringing true, ringing home. Those small words given into the night had been truer than anything else John had ever said. "I always hold to a promise, even this one. I came back for you through all obstacles. And it was far from easy."

For the first time, Sherlock was truly able to see all of John's compact person. Earlier the light had been playing tricks upon him, had cast him into shadows fit for poetry of epic proportions, but now it only left him with no place to hide. John's face was beaten and bruised, his eyes red rimmed but determined, dark with countless deaths staining his soul. His body was hidden by several layers of thin but dark clothing, most likely stolen or taken from people he'd killed from his path, and Sherlock suspected that beneath those layers would be the same pattern of bruising. Bruising that no one would question because they wanted answers from him more than they wanted good health. He'd have years to recover, after all, and what did those dead have?

It pained him to think that Lestrade had stood by and done nothing.

But after tonight it wouldn't matter anymore.

"Will it be quick?" He decided on, a simple question, precise and right to the point. Literally, the point of John's knife. "Or will you drag it out?"

"Are you afraid?"

"Yes." Sherlock said in a rush, his word no louder then the barest of whisper lost to the night, his face cast away from John's own searching one. "But not of you."

Of what's after is left unsaid but heavy in the air around them.

"We'll face whatever there is after life together, Sherlock. You might only have to wait a few moments for me, or a lifetime, but I swear I will join you." John stood up then and walked the few steps until he was right before Sherlock's chair, his knees hitting the carpet with a dull thunk that was sure to alert Mrs. Hudson if she was even still alive. "You're not going alone. I promise, I will follow you into the dark."

"I think I love you, John. However a sociopath might love a psychopath." Sherlock gave a wet laugh as John's empty hand found one of his, both clinging tightly to one another in the whirlwind of emotions and chaos they floated in. "A shame I never saw it until the end."

"You saw it before now, Sherlock. And so did I." John sighed into his ear as they leaned forwards, an awkward hug of two dying men whose time had run out before John firmly but gently grabbed a fist-full of Sherlock's curls at the nape of his neck, tugging gently backwards. "I love you too, Sherlock, however a madman might love another."

Sherlock didn't even feel the blade across his throat.