A/N: This idea came to me a while back and I just had to start typing.

WARNINGS: CROSSOVER FIC, blood, gore, torture, language, adult themes, weird stuff… (smirks sheepishly) Hey, it's me. What else did you expect?

DISCLAIMER: Oh, if only…! These characters visit my dreams sometimes. That's pretty much as close as I get. (sighs overly dramatically)

Awkay, now I'm stalling. (gulps) Seriously, I hope that this'll be a good ride!

The Sign of the Four

Secrets of the Dead

Dr. Spencer Reid was utterly exhausted when he dragged himself into his apartment, blinking sluggishly against the exhaustion three days without any sleep had left weighing him down. The case had been a hard one and all he would've wanted was a full day's worth of sleep. Fate, however, seemed to have other plans.

Spencer had barely closed the door when his cell phone began to ring. He blinked once more before gathering the coherence it took to grab the item and give it a look. He frowned upon seeing who the caller was.

He never called.

Spencer hesitated for a second. Then gritted his teeth and accepted the call. "Hello?"

There was a unidentifiable sound before a male voice, colored by a British accent, spoke. "Um… Hello. Is this… Is this Spencer Reid?"

Alarm bells went off in Spencer's head. That wasn't his voice, either. "Yes. Who am I talking to?" And what, exactly, was going on?

"Sorry. I'm Watson. John Watson. Sherlock's flatmate." Ah, that made sense. Sherlock had mentioned John a lot in their bizarre text message exchange. It didn't make the whole phone call any less alarming, though. Was that a sob? "I… found your number, from his cell phone, and… I thought that I should… should call you, before… you find out elsewhere."

Cold filled Spencer's whole body. The alarm bells from before were deafening. "What happened to Sherlock?"

Yes, John was definitely sobbing, although it sounded like the man was trying to smother the sounds. It took ages before the words actually came. "Sherlock, he… he's… dead."

Three Years Later

At the age of thirty-two Amanda Freeman, a strikingly beautiful woman with curly blonde hair and huge blue eyes, had been a high class working girl for so long that she'd long since learned certain rules. No real names. No feelings. And, most of all and foremost, full confidentiality. Whatever secrets her customers spilled during moments of heat they were hers to keep. They paid her more than enough to seal her lips.

She enjoyed her job more than she should've. But there were times when she got very, very bored. That was when her second boss came calling.

Entering a apartment she'd never seen before Amanda glanced around, not switching on the lights although every inch of her desiderd to. This was a part of their deal, a test. Failure and disobedience… were not options.

Amanda gritted her teeth, her steps hesitating. Her high heels sounded unnaturally loud in the non-furnitured space. "Do you… have an assignment for me?"

Her nerves were so strained that she jumped at the sound of a received text message. Dread sending chills all the way to her spine she accepted it. The second she took in the words she knew that her time was running out.

'You let them get a hunch of you. Compromised us both. That's why I want to play a game.'

There was a security camera. Had to be. Because after exactly five steps her phone bleeped again. Precisely at the same moment she noticed a bottle that had two pills inside it, left in the middle of a empty room.

'Choose. Live, or die? It's entirely up to you. I promise.'

Amanda shivered, her whole body filling with such cold she'd never, ever experienced before. She swallowed loudly, her eyes darting around furiously. There, in the corner, she finally saw the camera. Her eyes narrowed. "What if I refuse?" It was a miracle how biting her tone managed to sound, considering how badly her whole body was trembling.

Almost in an instant, as though her boss had been expecting such a response, a red dot appeared to dance on her unevenly moving chest. She received a one more text message. The last one.

'I insist.'

Six hours, fifteen minutes and thirty-eight seconds later Amanda was certainly not alone, either. Three pairs of sombre, frustrated eyes stared at her body that lay on the floor of a practically empty apartment. Considering her profession she wouldn't have minded terribly even if she was alive.

Jonathan Robinson from the local police inhaled loudly, looking away from the corpse. "She took poison. It killed her in seconds." He glanced towards his companions who stood only steps away with stony faces. "Do you think she's our killer?"

SSA David Rossi nodded slowly, a deep frown appearing. "She was. But… Something's… not right here."

Jonathan blinked twice. "What do you mean?"

SSA unit chief Aaron Hotchner gestured subtly, almost unnoticeably, towards one of the room's corners. "She wasn't alone when she died."

Confused and curious Jonathan glanced as subtly as possible towards the direction. That was when he saw it. A tiny surveillance camera. A tremor crossed him. Were they still being watched? "Do you think that she was giving one of her clients a show?"

Aaron shook his head, forehead creased. "I don't know. But… When we first came in there was a scent of cologne lingering in the air. A man was here only moments earlier. Chances are that it was the one observing her."

Jonathan sighed, running a hand through his shortcut dark hair. His almost black eyes darkened still. "Whoever it was, we'll have to bring him in for questioning. We need to find out what he saw and what, exactly, she'd been doing before her death."

Aaron nodded and opened his mouth but was interrupted by David. "Aaron." There was a look of mild alarm on the older man's face. "Where's her cell phone? She doesn't have it."

Jonathan blinked twice. "Cell phone?"

"We don't know what's going on", Aaron admitted through gritted teeth, visibly hating the admission. "But something is wrong with all of this."

Jonathan fought the urge to snort. Well, obviously. Three men and their killer are dead. "What do you mean?"

David replied for Aaron, still eyeing on the woman's body. "Someone of her profession would've never handed out their cell phone willingly. It may be our only lead to the mystery man."

Back at the station Spencer gritted his teeth and inhaled sharply as the news reached him. They'd been too late. They had three brutally murdered men and their most likely suspect was dead, taking all her secrets with her.

Gritting his teeth Spencer refocused on the map of locations, time lines and clues he'd put together. A million route marks that led nowhere. But there had to be a pattern, somewhere buried into that spider web. What was he missing…?

So focused he was that he jumped at the sound of his cell phone ringing loudly. He frowned at the unfamiliar number before making the decision to pick up. "Reid."

"Is this Dr. Spencer Reid? I'm Dr. Martin Gatiss from Memorial Hospital." The other man cleared his throat, clearly unsure how to set his words. "This… is highly unusual, but… I'm calling on behalf of a patient. He's determined to get in touch with you and he's getting highly agitated."

Spencer swallowed thickly. Curiosity, or perhaps something else completely, took over in the end. "What's the patient's name?"

"Sherlock Holmes."

Spencer's heart skipped a beat and for a moment he felt so lightheaded that he had to take support from the nearest table. It took far too long before he managed to squeeze out the words. "I'll be on my way right now. Don't let anyone approach him until I get there. Don't try to cuff him, either – it'd be of no use. But… Be sure to have several security guards nearby. Make sure that he's kept an eye on. He'll ask you a lot of questions. Don't answer them."

The confusion could practically be heard long before the words were. "What… What's going on here?"

Spencer was already speeding through the hallways, his mind going a million miles per hour. This just couldn't be possible…! "The only Sherlock Holmes I know died three years ago. I don't know who your patient is but he's not good news."

When Spencer got to the hospital he was pleased to discover three security guards standing behind the door a visibly shaken Dr. Gatiss pointed for him. He flashed the guards his badge and they allowed him to enter with a degree of hesitation. What Spencer encountered upon walking into the room made him freeze dead on his tracks.

Whoever the person in the hospital bed was… he was the perfect replica of Sherlock Holmes. Apart from a far lighter hair color and a scar tainting the stranger's cheek. The sight made Spencer's blood run cold.

Then their eyes met, hard and calculating. They narrowed at the exact same time with concentration. Deductions were buzzing between them.

The man in the bed was scarred and malnourished.

Irritation – Spencer could see the other's left eyebrow twitch.

The stranger's long fingers were drumming restlessly. Too much long term exposure to adrenaline. The body had forgotten how to relax.

Bruised knuckles, results of a recent fist fight.

"They found you collapsed from a pool of blood." It took a second before Spencer realized that he was the one who'd spoken. He frowned. "Yet the only new more severe wound found from you was a bullet graze. So whose blood was it?"

The stranger's eyebrow bounced up. "I come back from the dead after three years." The british accent was thick. That tone of a voice sounded familiar. "And that is the first thing you ask?"

Spencer decided not to comment further. Instead he offered the man a neatly wrapped sandwich. "I figured that you might need this."

Somewhat hesitantly the patient took the offering and began to eat slowly. Those eyes never strayed from him for longer than a second or two. It took almost a full minute before the man spoke. "You still don't believe that it's me."

Spencer's eyebrow rose. He took the chair by the hospital bed, his moves far more stiff than he would've liked. "Can you blame me?"

The man shrugged, still eyeing on him. Then began to speak. "You've grown a lot from the last time we were in contact. I can tell that you've been through a tragedy. You've been shot to the leg and it still pains you whenever the weather gets cold or damp – obviously you didn't take too good care of yourself while recovering. If I'm no stranger to substance abuse neither are you. That part of your life will never stop haunting you. Your hand still shakes whenever you're not fully focused on something. You don't get enough sleep. The nightmares keep you awake every single night. And you still write to your mother every day, don't you?"

Spencer gritted his teeth, a bit more taken aback than he would've liked to admit. He collected himself for a second before speaking. "You're going to have to do a lot better than that to convince me that the dead can come back to life", he pointed out.

The man actually smirked, just a little bit. "I'm sure that you remember precisely what my opening line was when I first texted you. I asked you if you're a terrorist. Your doctorates had me… curious."

Spencer shivered, feeling lightheaded once more. "We're going to do some tests to verify your identity. You'll be interrogated. I'm sure that you understand that. But, let's assume for a second that I believe you." He frowned, looking into those eyes and trying to see. "Why are you back now, after all this time?"

The look in Sherlock's eyes… It was unlike anything he'd ever seen before. Such that tore at his heart. It took ages before the man managed to speak. "John's gone missing. And…" It seemed to hurt physically to say the following words. "I'm not sure if I can find him alone."

TBC, OR NOT?

A/N: So… How's that for a startout? Good, bad, lukewarm? A bit of not good?

PLEASE, leave a review to let me know! This is my first x-cover fic EVER, so I'm really nervous right now. (gulps, and offers some pribe cookies) Awww, c'mon, one good deed per day, remember?

ANYWAYS, thank you so much for reading this far! (hugs) Who knows, maybe I'll see you again later.

Take care!