This is a crossover that just sort of... happened in my head today. I had to get it on paper, and I hope you enjoy it:) I do not own Sherlock or Merlin... obviously, because if I did, season four would be filming already and Merlin would not have been canceled. That said, here's my short story :D

In the Eyes of an Immortal

By Etimire T.

The memories started in his dreams. As a child, Sherlock ignored them because they were ridiculous.

But once he grew older, the dreams became not worse, necessarily, just more vivid. He would wake up shivering from the cold of a snowy ride through the night with his armor sticking to his skin. He would sweat and gasp and wake up clutching non-existent wounds he acquired in battles

The castle in his dreams was airy and large, bustling with life, and yet, the people were stifled by fear for a reason he could not quite remember. There was a woman there with dark, curly hair and a man who annoyed Sherlock to no end, but he couldn't do without.

And the strangest thing was while he was dreaming Sherlock wasn't himself. Well, that's not true. He was himself, but he looked different. Blonde, not nearly as tall, and always dressed medievally. But it felt… right.

It took years of denial and careful research to identify who he dreamed about. It wasn't possible. It was ridiculous and strange and insane, and if he told anyone, they would throw him in an asylum for sure.

But what does one do when every single night of your life, you relive a moment that you don't remember living? The dreams felt like memories. They were too detailed; too exact to be his imagination.

Sherlock was not interested in history unless it pertained to crime. The stories of King Arthur and the Round Table certainly did not qualify.

So why when he read the stories later on, did his dreams find so many similarities? They were not exact copies, but the basics of the stories were the same.

Well, then there was only one explanation.

Sherlock rubbed his eyes and shut down his computer screen.

No. This was ridiculous. It was coincidence; a really unlikely coincidence, but nonetheless, a coincidence.

Unless he came up with more proof, there was nothing Sherlock could do but continue the dream and remember day by day.

MSMSMSMS

Mer- no. His name was John now.

John stared at his reflection with satisfaction.

Well. He certainly wouldn't draw attention looking like this. Short, fading blonde hair, a cane. But his eyes… Drat it, he could never hide his eyes. They looked as vibrant as the day he first arrived in Camelot hundreds of years ago. It fascinated him, the life that lit his eyes. He was old. His eyes should look old. They didn't. Why?

But no one would look close enough to see his eyes. Surely no one would notice. His disguise would take care of that.

And that was good. After his experience in World War 2, he was quite done being watched. Maybe this time he could disappear for good, fade into the background and no one would ever know.

He even gave himself a typical name. John Watson. No one expected he was anything other than one of the other war veterans living on government compensation.

A funny thing about therapists, his limp wasn't psychosomatic, it was fake. An easy mistake, but a big one and easy enough to pull off on John's part. He certainly had enough baggage to need a therapist, but his pride kept him from taking advantage of her help. She was just a part of his guise anyway. His whole life was a mask to hide who he really was, at least until some of the crazy conspiracy theorists calmed down. It seemed to take much longer than it usually did this time. The theorists were convinced that Camelot was being reborn after he accidentally dropped his guise in public and ended up a prisoner at a government facility. Idiots. Under drugs, he spilled his guts, and a few people caught a whiff of the story.

Not many people believed him; just the crazy ones, which was not necessarily helpful.

So now here he was, hiding in plain sight as John Hamish Watson.

MSMSMSMS

The first thing Sherlock noticed when he met John Watson was the man's eyes. One could almost miss them, hidden behind that careful smile and simple clothing. But it was there; a spark of familiar light that instantly made Sherlock snap up from his work. They shined bright blue, curious and excited, full of dry humor.

Sherlock wondered how someone could keep that much vitality hidden so well.

It took many months of living with John Watson for him to identify the light.

Hope.

But for what?

"Are you… waiting for something?" he asked bluntly one evening.

John's ever-bright eyes flicked from his laptop, and he frowned. "Why would you say that?"

Sherlock shrugged and let himself fall sideways down his armchair so that his knees and neck rested on opposite armrests. He shut his eyes before answering with a shrug. "You're… hoping for something to happen or someone to come… back maybe? I'm not sure... What is it? What are you waiting for?"

John blinked. He was used to the detective's blunt manner, but this question put him on edge. It was far too close to home. Could Sherlock possibly think-? No. "I don't know what you're talking about, Sherlock."

"Uh, huh," came his not-convinced reply, but Sherlock didn't press the issue.

That night Sherlock had another dream. That in itself wasn't unusual. He always dreamed about Camelot. But this time something was different. This time he finally saw the face of the dark-haired man that was always at his side. The man who tried to save his life.

And when Sherlock woke, jumping clumsily out of the armchair that he fell asleep in the night before, he could have sworn he'd seen those eyes before.

He scrambled around the flat, desperate to save the face before it faded away. Sherlock didn't consider himself to be an exceptional artist, but he could get by. Drawing anatomy year after year honed his skill. Hastily, he grabbed a pencil and paper at random and sat down in the middle of the floor. Taking a deep breath, he closed his eyes and brought the man's face to view.

Opening his eyes, Sherlock's pencil scratched against the paper and within ten minutes, he sketched a rather accurate drawing of what he saw. He stared at the man he had drawn, just a boy, really. He had dark, messy hair and high cheekbones that distantly resembled Sherlock's, but the boy's sunny smile put that comparison to an end.

And his eyes… he had such bright, hopeful, vibrant eyes. Sherlock knew those eyes. It was like he saw them every day of his life...

What was the boy's name? Sherlock racked his brain, hardly noticing John making his way to the kitchen. John yawned and grunted at the moldy coffee grounds in the coffee maker.

Sherlock noticed but he did not let this distract him.

If he was dreaming about Arthur, then who could the boy be? A servant of some sort? He was dressed as such. But the emotion that followed him... the boy seemed to mean much more to him than a mere servant would.

The boy was Arthur's friend. Who was Arthur's friend in the stories?

Sherlock frowned and stood swiftly as the answer arose. "But he's not old!" he exclaimed loudly, almost arguing with himself. "He's always old in the stories!"

John frowned from the kitchen. "What the heck are you going on about?" He knocked the bad coffee grounds into the trash can and sighed. "Would it kill you to put on a pot every so often?"

Sherlock only barely listened. He shot his reply before melting back into his thoughts. "Why should I? That's what I have you for."

For a reason Sherlock could not comprehend, John chuckled. "You remind me of someone I used to know."

"Fascinating," Sherlock answered in a tone that implied he thought the opposite.

"Yup," John nodded and wrinkled his nose at whatever was growing in his cup. "He was a dollophead as well."

That finally caught Sherlock's attention enough to draw him away from his musings. "Dollophead isn't a word."

"Oh, really."

"Yes."

"Well…" John turned toward him and shrugged. "I say it's a word, so it is."

Sherlock rolled his eyes, mildly annoyed. "You can't just make up a word."

"Why not?" John smirked lightly. "Shakespeare made up words, didn't he?"

Now Sherlock finally turned to glare at John. "You're not Shakespeare."

"True," John shrugged, "I'm even cooler."

"Really. How so?"

John shrugged and looked as if he would reply but then he shrunk a bit into himself and turned away. "Oh, whatever." He frowned at the coffee pot and changed the subject. "Just... Sherlock? I can deal with you experimenting with the coffee pot but if you so much as touch the tea pot-"

"-You'll do something extremely unpleasant," Sherlock finished with an eye roll. He collapsed on the couch, successfully distracted from his strange dreams. He waved John away. "Go to work, John. And bring home an interesting murder case if you come across one…"

John snorted and tied his shoes. "Yeah, whatever. I'll certainly do so because it's completely normal to just 'come across' a murder case…"

"Now you're getting it."

John made a noise that insisted that he didn't.

But that night he came home shouting about Lestrade trying to get a hold of them and do you ever answer your phone, you idiot?!

MSMSMSMS

John found it quite difficult to strip magic away from his life. It was a part of him, instinctual like breathing. He was used to using it almost constantly. However, he soon found that living with Sherlock Holmes meant he had to be very careful.

Yet, despite his discipline, there were a few times that habit won out.

"John?"Sherlock shouted from the kitchen, "I thought the sink was broken!"

John froze. "It is."

"Hmm…" John clearly heard the detective turn the water on and off. "No, it's not." There was a moment of silence and then, "Wow. The water tastes great."

Silently, John closed his eyes and cursed his absentmindedness. That morning he placed a hand on the faucet handle and seeing that it was broken, his eyes flashed and instantly crystal-clear water flowed from the spout. It was instinctual and require no effort on his part, but now the sink was fixed with no apparent reason to be so. He stood and walked to the kitchen. "Weird," he said, "Maybe it worked itself out."

Sherlock nodded slowly and glanced at John, but as far and John could tell, he didn't notice anything odd about his flatmate's behavior.

That was close, John thought. He needed to be more careful.

MSMSMSMS

There were other times that it became necessary for John to use magic to save his and Sherlock's hides.

Their feet pounded on the asphalt as they rounded the corner, panting, covered in dirt and soaking wet. "You had to provoke them!" John hissed.

"I was using a very tactical technique-"

"Oh, shut up. We need to hide." Quickly John tugged Sherlock underneath one of the cars in the parking lot. They lay flat on their backs, side by side.

"You," Sherlock started, "have done this before."

"I was a soldier, Sherlock."

That was true. Almost. He did fight in Afghanistan, but not as a soldier. He helped the British troops from the shadows.

Their current situation drew very many similarities to the situations him and Arthur used to find themselves in, John noted. A part of him ached, hoping Arthur wouldn't feel betrayed that he found a real friend for the first time since Arthur had died. Actually, he had not been this close to anyone since Arthur.

This realization startled John, but at the same time, there was a feeling of rightness that made John smile wistfully. He really did enjoy danger, despite his cautious ways, and he really did enjoy friendship. How did he forget what it was like?

But right now was not a time to wonder. The thugs would be here any moment, and they would beat the crap out of them unless he did something.

Turning his head to the side, away from Sherlock, John waited for the tattooed men to round the corner. With a flash of his eyes, John caused all the men to stumble on non-existent wires and then planted the sound of running feet in their ears. They stood quickly, disoriented.

"I heard footsteps over there!" one man shouted, pointing away from John and Sherlock.

"So did I!"

And with that, they took off running, leaving Sherlock and John free to dash from the scene and point the gang out to the nearest police officer.

That night John sat on the countertop at Bakers Street, absently eating Chinese take-out.

Sherlock was in the living room, typing away on John's laptop.

"You're not planting a virus on it again, are you?" John asked, "Because that was not cool."

Sherlock snorted, but for once didn't take the bait. "Look here," He pointed at the screen.

John hopped down from his perch and leaned over Sherlock's shoulder.

His gut clenched nervously. "Is that a security camera?"

"Uh, huh," Sherlock answered. "The parking garage has three set up. I hacked into one and look at this…" He pressed play and John watched with apprehension.

In the video, the blurry forms of Sherlock and John dashed across the parking lot and they hid beneath an SUV. Seconds later, the dozen or so thugs rounded the corner and Sherlock paused the video.

"I'm going to slow it down," he said, "Watch."

Simultaneously, all of the men jerked to a stop and fell in slow motion to the floor. John shrugged. "They tripped. Lucky for us. Maybe there was a wire."

Sherlock shook his head. "No, we ran right through without falling. And look, see the man in front of the others? When he falls, so do the others. That wouldn't happen if there were a wire. They would all trip at the same spot if they were stupid enough to keep running."

Shrugging, John rubbed his eyes and turned away. "I don't know, Sherlock. We were lucky. Does it really matter how the men tripped?"

"Yes," Sherlock clipped, frowning. "Yes, it does."

John groaned, hiding his nervousness. "Whatever. I'm going to bed."

That night, Sherlock stayed up late, watching the video over and over again. He was certain he saw something like this before. In his dreams maybe?

Yes. Definitely. Weird stuff like this happened all the time in his dreams. And wasn't it the dark haired boy who caused it? Strange…

MSMSMSMS

John knew he was probably the most powerful person on the planet at any given time, but he was human and humans are fallible. He made mistakes. He grew tired and needed sleep occasionally.

After a long day at the office, he was more that exhausted. He was undone.

John was a good doctor. He healed his patients problems more often with magic than medicine, but he also was a master at the medical trade. When he could, he eased the pain of minor injuries or tweaked something just slightly to make recovery easier, but he also knew how to diagnose and treat a patient using the more... conventional methods.

However, after dealing with particularly irritating patients and guiding the hands of three surgeons from another room, John felt like collapsing right on the doorstep and sleeping for three years straight. He clomped up the stairs and practically fell into the flat he shared with Sherlock.

And of bloody course. Sherlock was playing his violin. Admittedly, he played it quite well. But John was not in the mood for noise. Or bright lights. Or breathing, for that matter.

"Do you have any idea how irritating (1)hypochondriacs are?" he spat upon entering, not really expecting a response.

"More irritating than I am?" Sherlock answered.

John opened his mouth and then closed it. "Well, on second thought, no. You are far more irritating. But hypochondriacs are close runner-ups."

Sherlock snorted, seemingly pleased that John still considered him more annoying than anyone else.

Sighing tiredly, John made his way to his bedroom. "I'm gonna take a nap. Don't burn the house down or something."

"Why on Earth would I do that?"

John stuck head head back around the corner to give him an irritated look. "I don't know, Sherlock. Why do you put toenails in the jam?"

"That was an experiment."

"Of course it was…"

Without any further comment, John stomped away and fell into his bedroom. He needed a nap. Now. Quickly he stuck his head out the door, intending to tell Sherlock to shut his violin up, but realized that the detective already put it away and was busy messing with a sketch book.

Huh. So he did know not to play when John was sleeping.

Wait. That meant he chose to play at three in the morning, that son of a-

John stopped himself.

Whatever. He was too tired to be angry with the detective right now.

Closing the door and locking it behind him, John closed the curtains and for the first time in several months, let the guise drop from his shoulders.

The effort it took to keep up the magic was not extensive, but doing it constantly for such a long period of time took its tole. Rolling his shoulders, Merlin took a deep breath and fell down backwards on the bed, relishing feeling like himself again.

"Oh, that's great," he murmured, stretching. Curiously, he inspected his hands, pale and long-fingered, not weathered and strong the way John's hands were. Man, he forgot how good it felt to be in his body again.

Merlin knew he was taking a risk, exposing himself this way, but he wouldn't stay this way for long. He closed his eyes and sighed contentedly. Just a few minutes longer and then he'd put the guise back on…

Just… a… minute… more…

Merlin didn't notice when he dropped off to sleep.

MSMSMSMS

Sherlock wasn't sure why he looked up when he did. He was busy sketching out the latest scene from his dreams.

A young woman, her hair ratty and her clothes torn, smirked at him from a throne. Along with the woman's face came feelings of regret and betrayal and guilt and deep sadness. Why did she hate him so much?

All at once, Sherlock dropped the sketch book onto the table and frowned. Something was… different. He wasn't sure what, but Sherlock was certain that something changed in the air around him.

Slowly he stood. Was this apprehension he felt? Sort of. He couldn't identify it.

Quickly but quietly, Sherlock crossed the room and made for John's bedroom. Was it that John left and he only just noticed? Was that why he felt the way he did? Sherlock needed to be sure.

Without much thought, he tried the door and frowned when it jiggled but remained stubbornly solid. Locked. That was an easy fix. If John was sleeping inside, he'd just pick the lock and avoid waking him at all.

It took three paperclips and a matter of seconds for Sherlock to open the lock. He pulled opened the door and walked in quietly only to stop dead in his tracks.

On the bed, tangled in the blankets, lay a familiar form. His dark hair was longer than Sherlock remembered and exhaustion plagued the adolescent even as he slept, but it was definitely him.

Skinny and pale as death. High cheekbones, half a smile.

"Merlin," Sherlock whispered, his voice catching in his throat.

This wasn't possible. This couldn't be happening.

And where the heck was John?

Merlin shifted in his sleep and Sherlock darted out of the room, heart pounding.

Right. That was just a trick of the light. A trick made by his sleep deprived mind. When he went back in John would be lying-

"Sherlock?" said a sleepy voice that was not John's. "Was that you?"

Slowly, Sherlock pulled into the room once more. Staring apprehensively at the boy, he waited for the boy to realize he was being watched.

Blinking wearily, Merlin rubbed his eyes and yawned. All at once he froze, and his gaze shot up to Sherlock's. His eyes widened, and he gulped. "Uh, sorry," he said, "Climbed through the wrong window." He adopted a sheepish smile. "Look, if my parents realize I broke curfew they would kill me. I'll just…" He stood quickly and moved toward the window. Sure enough, the window was open just a crack. Wasn't it locked a moment before?

Quickly, Sherlock moved forward and Merlin stopped. "Aw, come on, man," he begged, the perfect image of a naughty teenager. "Just let me go. I promise I won't ever bother you again."

Sherlock almost believed him. Almost. The boy certainly was clever.

If he hadn't heard Merlin call him by name a moment ago, he would be satisfied that the boy really was a stranger. But he couldn't be. He knew that Sherlock Holmes lived in this house and it sounded as if he knew him well.

And… he wore John's clothes.

This realization sent a shock of electricity through the detective. Sherlock shook his head rapidly, gulping. "No," he whispered, "No. It's not possible."

Merlin blinked, confused. "What?"

Shivering, Sherlock planted a hand on the wall. Merlin was sleeping in John's bed, wearing John's clothes.

And he had John's eyes.

They were the same eyes.

"John?" Sherlock croaked. It was him. Somehow, this boy was John. Sherlock was certain.

Instantly Merlin's face paled. He recovered quickly, but not quickly enough. "John?" he asked, "Who's John?"

"Oh gods," Sherlock breathed, "It's you," Sherlock hardly believed his words. "John. You're the warlock. How could I be so stupid!"

Merlin turned fully toward Sherlock and cocked his head. Complete shock and incomprehension showed all over his face, shining within his deep blue eyes. "How-?" he started. "Do you know who I am?"

"Of course I know who you are!" Sherlock replied sharply. " I've only dreamed about you for years! But I thought you were just a- just a figment of my imagination!"

Merlin stood so still, he could have turned to stone. "What?" he said slowly.

Sherlock felt frozen as well. This was proof. Finally, proof that he wasn't crazy; that his dreams were real, to some extent. But the alternative to insanity… was not much better.

"Merlin… or Emrys if you prefer. Bloody-" Sherlock stopped himself and hissed, rubbing his eyes as a sudden stab of pain eclipsed his vision.

Instantly Merlin stood at his side. "Sherlock? Sherlock what's wrong?"

"I'm… f-fine," he ground out.

And a moment later, he was. He stared in wonder at Merlin once more. "Jeeze. Of course you're John. You have the same eyes. I knew I'd seen them before."

Merlin held up a hand, slowing down Sherlock's words. "Wait- wait a sec. I don't understand. How do you know who I am?"

Sherlock just shook his head and all at once stumbled backwards and out of the room. His brain felt like it was turning to mush and his mind palace rearranged against his will.

He made it to the kitchen, Merlin running after him shouting his name, before Sherlock collapsed on the floor. He grabbed his head and growled. "W-what's wrong?" he hissed. The pain was like a million little needles sticking into his temples all at once.

Merlin knelt next to him and grabbed his hand. "Sherlock, look at me."

Sherlock did, but this only resulted instantly in another stab of pain. Thousands of memories poured into his head all at once and it bloody hurt.

"No. No, Sherlock, you have to keep looking at me."

That wasn't Merlin's voice.

Instantly Sherlock flickered open his eyes and met John's gaze. John smiled kindly, but his concern was blatantly obvious. "I'm not sure what's happening, Sherlock, but just wait a minute. I'll try to make this easier on you." Gently, John placed a hand over Sherlock's eyes. Immediately, Sherlock felt lulled into unconsciousness and he welcomed it gratefully.

MSMSMSMS

Sherlock woke up hours later feeling surprising alright. His headache was gone and he felt strangely… light.

And yet, something was different. It took him only a moment or to to identify it. His entire mind palace was rearranged, but not in a way he disliked. There were now two distinct and very separate wings.

In one wing were all the memories of the entire life he led now, being a detective, living with John, bickering with Mycroft, but in the other were new memories that he was only tentatively familiar with. However, after browsing the shelves for a moment, he was overcome with a sense of rightness that he couldn't quite understand. How on Earth did he forget about all of this?

Training with his father. Learning how to be diplomatic. Fighting a dragon. Leading his country. Fighting battles, for heaven's sake!

Sherlock's eyes flew open and he sat up suddenly, scaring the wits out of John, who sat in a chair at his bedside, browsing Sherlock's sketchbook. When Sherlock jumped awake, he started, dropping the book on the floor.

Sherlock blinked at him and for a moment both men just stared at each other.

"I believe it's considered rude to flip through other's private things," Sherlock said bluntly.

John let out a shaky breath, obviously relieved that he was awake. He looked Sherlock up and down. "Sorry." John paused and then continued. "Are you feeling alright?"

Slowly, Sherlock pulled his legs to the side of the bed. "Actually," he murmured, "I feel great. What'd you give me?"

"Magic."

Sherlock opened his mouth and then stopped as John's reply sunk in. He frowned thoughtfully. "If I didn't happen to have a boatload of new memories in my head, I would be very tempted to think that I was drugged a bit back." He studied John carefully. "In the bedroom? Did that really happen?"

Slowly, John exhaled, his eyes unreadable. "Yeah. Yeah it did."

Sherlock's eyes fell to the floor. "How?"

"I can show you, if you like."

Instantly Sherlock's eyes jerked back up to John. "Do it."

John nodded and then, sitting in that chair, notebook now in hand, John changed. His hair darkened, his facial structure shifted into that of a young man's, and within three seconds time, an entirely different person sat in the room. Long and lanky, pale and mischievous. Merlin. There was no denying it.

Sherlock knew him instantly but said nothing, too shocked to come up with a reply. "I-" he started. He coughed, and continued. "I take it that this is your true appearance?"

"What makes you think that?" The boy's voice was soft, almost guilty.

Sherlock looked straight into his eyes as he replied. "Because this is how I remember you."

Merlin frowned, confused.

Sherlock rolled his eyes. He was so slow. "Really, Merlin, you are no smarter than I remember you being."

Merlin still wasn't getting it. "I don't-" All at once, realization dawned in Merlin's eyes. He sat back quickly, apprehensive. "You're not-?"

Sherlock nodded. "I am." He cocked his head. "Well, sort of. I don't blame you for not recognizing me. Up until a few minutes ago even I didn't recognize me." He frowned. "That is the strangest sentence I have ever said."

Merlin just blinked. "Is it... is it really you? Arthur?"

Sherlock smirked. " Now you've got it. Hello, Merlin. The world is a strange place, isn't it?"

Merlin let out a shocked, relieved, disbelieving burst of laughter and grinned. "Yeah. Yeah it is."

Together, sitting in the living room of 221B Baker Street, the two legends spoke long into the night. There were many questions and only a few answers, but for now that was alright. For now, being alive together again was all they desired. They could deal with what came later when the time arrived.

AN: Thanks for reading folks! I hope you enjoyed it. I MAY make another one-shot related to this story, but I'm not sure yet. Just mark my profile and wait a bit if you want some more:) Please leave me a review, I really appreciate it!