So this is a crossover of BBC Merlin, Once Upon a Time, and Harry Potter. Once I saw the season 4 finale of OUAT, I knew that this just had to be a thing, at least combining it with Merlin BBC. But, I didn't have a good enough idea for it at the time and it sat undone. And then, I had a dream about these 3 fandoms coming together and I knew what I wanted to do. Magic. And thus, Harry Potter was added into it and things started weaving together and criss crossing and things kept getting tangled with each other so that it created a veritable web of magic. Hence the title.

Spoilers for all 3 fandoms up to end of HP (follows the books), end of Merlin, and end of season 4 for OUAT.

Summary: Emma becomes the dark one and starts to terrorize London, Merlin has to fix a couple thousand year-old wrong and Harry Potter has to battle another Dark Lord… Lady… Also starring: Henry, Snowing, Outlaw Queen, R/Hr, H/G, Elaine (kind of an OC), and other BBC Merlin chars later :D

Chapter 1: Collide

HENRY

Henry felt his blood run cold as he heard his family yelling outside. He looked up at Belle, who gave him a quick nod to say she'd take care of things here, and then he was out the door. The first thing he saw was the swirling vortex of darkness enveloping someone. At first, he thought it was Regina, but a closer inspection revealed it to be his other mom. Sprinting as fast as he could down the road, he was only able to hear her say "I love you" to Hook before the darkness overcame her and she was gone. He watched the dagger clatter to the ground and he felt like the whole world had just stopped moving.

"What… just happened to my mom?" Henry barely managed to choke out as his brain sorted out what just happened. His mother, one of them at least, was gone. Lost to the darkest force this world or any other would ever know. Tears threatened to fall at the corner of his eyes, but he didn't want to cry. Crying wouldn't solve anything right now, nor was there any time to deal wit the emotions threatening to take over. He had to save his mom.

Immediately, Regina detached herself from Robin Hood, (a small part of Henry was happy to see them together, only to be quashed by the overwhelming loss of the moment) and went to comfort her son.

"It's ok, Henry. Emma… she absorbed the darkness. Wanted to contain it so it wouldn't hurt anyone," Regina spoke softly as she hugged Henry closer to her. Henry hugged her back, wanting to gain any amount of comfort he could at the moment, at least until he processed everything and could decide what to do. They stayed like that for a minute, and Henry could hear everyone shuffling around nervously, afraid to ask the question that needed an answer.

"Is she okay?" Henry finally decided to voice it.

"I don't know, luv," Hook answered. Henry broke the hug to look at him while Regina repositioned herself so she had a hand on his shoulder.

"We need to find her," Snow spoke up after a moment, and Henry saw her look to Charming for confirmation who nodded.

"I want to find her, too, but we don't know where to start," Hook said, waving his hand around in a circle for emphasis. Henry was about to voice that they should go find Merlin when a new voice interrupted them.

"It's finally happened then." Henry turned around to see a blonde haired woman walking down the street. He recognized her face, but couldn't quite place where or how he knew her. Whoever she was, she had an air of regality about her, despite wearing a simple floor length dress. It was in the way she stepped lightly on the ground, how her head stayed level, or perhaps it was the blueness of her eyes. Her entire aura simply demanded the attention and respect of every person who saw her.

"What's happened?" Regina asked, and Henry felt her hand clench on his shoulder.

"She's been overcome by the darkness," the woman answered, still not introducing herself.

"You knew this would happen?" Snow demanded, and Henry could see everyone tensing for a fight.

"Mom, who is she?" Henry whispered as the woman paused to gather her thoughts. He had a feeling he should know this woman, but couldn't quite place where or how.

"She came with the latest curse, opened a jewelry shop downtown."

"Who was she before the curse?" Henry pressed on as he racked his brain through the book of fairy tales trying to see if anything came to him.

"I don't know," Regina confessed, "I never thought to ask." Henry wanted to press his mother for more information, but the woman started speaking again, choosing her words carefully.

"I knew it would happen, yes, but I did not know when or how. I am a seer, and many years ago I saw this event happening."

"Why not tell us then? Maybe we could have prevented it," Charming challenged the woman, but she only nodded in response.

"Perhaps I should have. But in telling you, you could have committed a more grave sin trying to prevent it. As a seer, I often see people go to great lengths to avoid one future, while creating something entirely worse. And even then, they do not escape their fate."

Henry thought about Rumplestilskin and the story of the blind seer. How he went to such great lengths to try to prevent her prophecy, only to make it come true on his own and in the worst way possible.

"So why come forward now? And who are you?" Henry asked calmly, trying to bring the tension down. The woman turned to him, her bright blue eyes looking at him, looking past him, and he tried to suppress a shiver but failed. And then the woman smiled at him.

"Yes, I haven't met you yet, have I? My name is Elaine, I run the jewelry shop here and while I could do little to prevent her from becoming dark, I have been researching for a way to get the darkness out of her. Also, I think one of you should grab that dagger."

Everyone now just seemed to realize that yes, the dark one's dagger was just lying on the street for anyone to take. Almost as if everyone had decided upon this beforehand, everyone turned their gaze to Hook, urging him to be the one to take it. He gave a solemn nod and picked up the dagger before putting it in his cloak. Henry realized belatedly that she avoided answering his question about who she really was.

"Couldn't we use the dagger to call her back here?" Robin Hood voiced aloud. Everyone in the group gave a nod in mutual agreement before Elaine interrupted them.

"I do not think it would be wise to call her back here."

"You know where she is?" Snow asked with a little more force behind it than she had probably intended.

"Yes, she is in England at the moment, trying very hard not to come here."

"Why wouldn't she want to be here?"

"You have never seen someone before and after becoming the dark one. If she were here now, she would be trying to trick you into giving her the dagger. And if she could not trick you, threaten you with each other. Above all else, the dark one desires their dagger for they hate to be controlled."

"Why isn't she here then, if the dagger is here?" Regina asked.

"Because Emma was originally so full of light. She herself does not desire the dagger, and in fact wants to be far away from it as possible. She knows that if she were here, she would hurt you. So, she hides away. The downside to this is that the dark one is in almost complete control of her other actions."

"We can still tell her not to do thing right? Like not to hurt people?" Henry voiced, hoping it would be true. The last thing he wanted was for Emma to come back to herself and realized that she had killed numerous people.

"Yes, that should be possible," Elaine conceded and waved a hand at Hook to tell him to do the honors.

"Do not hurt or kill or purposefully injure anyone," Hook spoke into the dagger. As Hook putt he dagger away, Henry noticed a slight tremble to his hand. So, Hook was feeling more nervous than he let on. Looking around them, Henry noticed that everyone seemed to be on edge, Regina's hand still at his shoulder and rubbing it in an effort to keep him calm, or maybe to keep herself calm? Henry honestly couldn't tell.

"We'll have to go to England on a plane then," Henry announced, bringing everyone back down.

"Why not just transport there?" Elaine asked.

"Well, there's no magic in England, right? Just in Storybrooke." Even as Henry said this, he could tell that he was wrong from the way Elaine's eyes twinkled.

"My dear boy, there is more magic in England than anywhere else in the world. You might even say, magic itself lives there. Also, what is a plane?"

"You've seriously never heard of a plane before?" Regina asked before she could stop herself.

"Regina!" Snow admonished, knowing that there were plenty of people in Storybrooke who were still trying to adjust.

"I'm sorry, I've been asleep a few thousand years. In the short time I've been awake, I haven't come across that word."

At this, numerous questions came to Henry's mind about how old she was and what she was doing before she went to sleep, but a sharp look from Snow told him it was better to keep his mouth shut for the moment. So Henry opted for something funny instead.

"It's a giant piece of metal with metal wings that uses fire to push itself across the sky." The look on Elaine's face, as her graceful features morphed into an expression of surprise and fear was totally worth whatever admonishment he'd get from Snow later. Someone had to keep things light around here, and who better to do it than him?

MERLIN

Merlin felt it when the Dark One escaped. His head exploded in pain and he clutched at it as he tried to deal with the surge of energy running through him, the earth's natural defense against the darkness. His heart beat like a drum in his chest, trying to control the magic as it raged in him. But he could not control it, he could not stop it. He was as he has always been, the earth's magical puppet. When the balance of magic went out of whack, the earth called on him to fix it, regardless of how he felt about it. Well, there was the one time it let him save a baby who ended up taking down the one of the worst Dark Lords in magic history. For that, he was incredibly grateful.

Many years ago, he attempted to get rid of this darkness, but was unable to. He fought it for years in the shadows, but even when he destroyed the vessel, the darkness lived on. The earth could not help him destroy it, there simply wasn't enough magic left after the great purge. So, Merlin did what anyone does; he swept it under the rug. Except, when Merlin sweeps something under a rug, he creates pocket dimensions for the darkness to roam around in until he can find a solution for it.

What Merlin did not anticipate was how full of life these microcosms of universes would be. It became a past time of his to write down what happened in these worlds and share it with others as he kept a watch over the darkness. They gained their own life, their own purpose! How wonderful was that?! Merlin watched these worlds grow for a long time, writing down what happened and changing things at times to balance out the darkness he created, until they started multiplying. Merlin may have a lot of time on his hands, but not even he had that much.

Still, Merlin wanted these worlds' stories to continue, and someone had to be there to control the darkness inside. There was a chance of the darkness growing too much and destroying the world it was in. As an added bonus, their stories could be written down and passed to the real world, as proof that they existed. So, he created a pen that could recreate and at times alter the stories of these worlds and let it select those he deemed worthy of the job.

Which worked fine until apparently this last Author screwed everything up in his own selfishness and let the darkness into the world. So now Merlin had to find a way to destroy the darkness once and for all. Goes to show that you can't put off the inevitable forever, even if you can avoid it for thousands of years.

As the burning pain in his chest went down, Merlin looked up from his position on the floor (how did he get on the floor?) to see a young woman staring at him. Oh yes, he was in his herb shop. Which makes sense, since that's where he's been for the last few hours today and every other day. He had set up shop in Diagon Alley a few years out of sheer boredom. It helped pass the days.

"Are you alright?" the young woman asked, bringing him back to the present again. Merlin blinked and his brain finally decided to wake up and process everything. She was in her early thirties, or late twenties, with thick light brown hair and appeared very concerned. Her hand was also extended towards him, just waiting for him to take it. Which he should do soon.

"Ah, yes, yes, it's just my er heart does that sometimes," Merlin responded, feeling only slightly guilty at the lie, as he took her hand and she pulled him to his feet. He tugged at his scarf a little in an attempt to calm down and gather his thoughts.

"Oh, well, I know a good recipe for heart pain if you need it," the woman offered, already opening a bag she had and reaching in.

"No, no, I'm good, really. I have my own recipe for heart pain." The woman seemed to remember where she was then as her head swiveled about, taking in the various kinds of herbs and ingredients that the shop had.

"Yes, right, I'll just continue looking then," she said and started to peruse the shelves more.

"Maybe I can help you find something then?" Merlin offered, having nothing better to do at the moment. Well, he could start researching a way to destroy the darkness, but he'd rather not have someone else here when he did that. Could be dangerous.

"Yes! I was looking for… hold on a moment." The woman pulled out her bag again and stuck her arm in up to her shoulder before pulling out a massive tome that would make even Gaius raise his eyebrows in astonishment. Even as the thought reached him, Merlin pushed it aside to better concentrate on the matter at hand. "These things, I can't pronounce their name and the other shop I usually go to didn't have them so I came here…"

"Hm yes, I have those here, but might I see the recipe you're making?"

"Well, I'm making 2 salves actually. This one," the woman flipped through the book and pointed out the page to him, "and this one," she said as she flipped forward some more, marking all three places with her fingers. "The first one should cool the affected area to stop the sizzling and bubbling, and the second one mimics the skin around it so that it will stay the same color until that naturally fades away."

"Makes sense," Merlin agreed, "but if you apply the second one after the first one, it actually starts to mixes with it and instead of mimicking the surrounding skin, it mimics the salve, which in this case… is a lizard. So he'd end up with lizard skin on his arm."

Merlin looked up from the book to see her staring at him in astonishment, before pulling the book away and examining the recipes more closely. Merlin heard her give a little gasp before exclaiming, "You're right!" and going back to staring at him in wonder now.

"Yeah, so unless you want him peeling off scales, which is really painful by the way, I would suggest using these," Merlin explained as he walked around the store picking up what he wanted, "and rubbing it on the affected area." He handed the woman the ingredients, who stared at them for a moment before riffling through her book furiously.

"There's nothing in here that contains these 3 ingredients…" she declared not even a minute later. Merlin didn't question how she had read through the book that fast, perhaps a charm for that existed now and instead rubbed the back of his neck nervously.

"Well, I could make it for you if you'd like…"

"Could you tell me the recipe instead?" she blurted out before he could even really finish. Merlin looked up at her again and he could feel the excitement rolling off of her as she rummaged through her bag again and pulled out some parchment and a quill. Merlin felt a little humbled; no one ever asks him for his recipes anymore, they just want him to make it for them.

"Sure. You must've been in Ravenclaw then, right?" he commented as he took the parchment and quill and began to write the recipe down. He didn't miss the mischievous smile she put on though at his words.

"You're not the first one to say that, but no I was in Gryffindor actually," the woman said with quite a bit of pride in her voice. It was only then that he recognized who she was, but to be fair it had been over 10 years since he'd last seen her. Hermione Granger, who fought alongside Harry to defeat Voldemort. The brightest witch of her age, or so he'd heard. The realization brought back a lot of awful memories of Merlin being helpless to save people from Voldemort's wrath, bound as he was to earth that decided Harry would be sufficient enough to defeat him. Not that it was wrong in the end, but it didn't stop Merlin from hating every agonizing minute of not being able to do anything while people suffered.

"Here you go," Merlin handed Hermione the recipe a minute later. She immediately began to look it over, dissecting it and figuring out how it worked. Merlin couldn't help the small smile he had then, he loved seeing people enjoy learning new things.

"Thank you for this, now if only we could find a way to cure stupidity," Hermione grumbled as she put the piece of parchment away and Merlin fought back a laugh. He could almost imagine Arthur saying the same thing about him. Arthur…

"Right, well, if that's all you'll need then," Merlin said, mostly to prevent himself from going down that dark path again.

"Yes, right, how much for the ingredients?"

"Just take them," Merlin dismissed. He hated charging people for herbs when they could be found naturally, well, some of them anyway. Others he had to grow on his own since people keep destroying the land, but even so. What need did he have of money? He rarely bought anything, preferring to grow his own food and make his own clothes.

"But-"

"I always love helping someone that like to learn. If you must pay me back, visit the shop more often. I get bored here," Merlin said with a smile. Hermione looked like she still wanted to protest, but in the end gave a small huff and rolled her eyes, probably remembering something else, before she looked back at him and smiled as well.

"I'll do that then, and thank you."

"No problem, have a nice day now," Merlin called she walked away and waved over her shoulder. He waited until she was out of site before he flicked his open sign to closed, drew his curtains shut with a wave of his hand and lit all the candles in the room with a flash of gold.

There was a lot of research to be done if he was going to find a way to destroy the Dark One once and for all. Merlin found himself almost looking forward to it; it'd be like he was back in Camelot again. Invigorated, he used his magic to pull books from their shelves. He must have been a little too invigorated, though, because one of them ended up smacking him in the back of the head. It seemed this would be just like he was back in Camelot then.

HARRY

Harry was not having a good day at work. First, he gets a frantic Patronus from Hermione asking if has anything or knows of anyone that has anything that could stop flesh from sizzling and bubbling and turning colors. So he asked around for a while with no results only to be interrupted as he got a call that someone managed to dig up a dark artifact in their basement. When he arrived there, apparently the house owner accidentally activated the artifact and it swapped their limbs with parts pieces of furniture in the room, which wouldn't have been so bad except one of them was a plant that became their leg. Then, when he finally dealt with that mess, Hermione informed him that she had already found a solution to her problem and didn't need him anymore. And just when he thought he could come back and take a break at his desk, he was hit with… well, he didn't really know.

"There's a sudden increase of dark magic?" Harry asked as Neville told him as he walked back into the office after wasting time not finding a solution to Hermione's problem.

"Yeah, word was just passed around," Neville confirmed, looking up from one of the reports on his desk.

"What does that even mean?"

"Don't know, no one does. There's never been anything like this before."

"Never?"

"There have been little spikes before, when previous Dark Lords were at their peak, but nothing on this scale before. The trouble is, it can't be pinpointed. The closest we can get is that it's concentrated in London somewhere."

"I suppose they'll want us to patrol the area then. Who's got first shift?"

"You," Neville replied with a none too innocent grin on his face. Harry swatted at him, but missed as Neville ducked away in time. "Good luck, Harry."

Harry rolled his eyes in annoyance, but went to get his battle robes anyway. Even if a sudden increase in dark magic didn't make any sense, it was his job as an Auror to go investigate it anyway and report back. He was thankful he renewed the charms on his robes recently; it wouldn't do to go on patrol and get taken out because his charms were weak.

Actually, he could make this kind of fun and still do his job. Excited by his own idea, Harry took out his bag and rummaged around until he found his Firebolt 4000 and invisibility cloak. After Sirius bought him his first Firebolt, he'd continued to buy all the new ones they came out with in his honor. Plus, they were really fast.

Harry mounted the broom and threw the cloak over his shoulders and brought the hood up. He cast a quick charm so the hood would stay on as he flew, practically second nature to him by now, and took off through the skies of London.

After flying through the air for an hour, he came to stop on a rooftop to think of a better idea than flying around aimlessly. He had half expected to see or feel a mass of dark energy as he flew around, but there was nothing. It was just the same city that it always had been. How could the energy be everywhere in London and he not feel a thing?

As he let his mind wander, the sound of sirens from the streets of London below reached his ears. With nothing else to do, Harry watched the scene below him. A car was crumpled up on a streetlamp, ambulances scattered around the scene and paramedics gathered around what Harry assumed was the driver as they laid him on the street. Even from this distance, it was obvious to Harry that they were trying to bring him back to life, but it didn't seem to be working. Harry was about to get back to work when something, or rather someone, caught his eye.

Standing against a streetlamp across the street was a blonde haired woman in a red jacket and jeans. Ordinarily, this would not have aroused his suspicions, but she was leaning so casually against the streetlamp as she watched the proceedings as others either observed casually while walking away or were watching the scene with intense concentration, praying that the driver would live. It almost looked as if she was waiting for them to die…

Harry was so lost in thoughts about the woman that he nearly missed it when the paramedics all stepped away from the man, silently declaring him dead. He instantly swiveled his head back to the woman and found that she was gone. Quickly, he scanned the surrounding area, trusting his eyes that had scanned the Quidditch pitch for the Snitch for 6 years at Hogwarts, but she was gone. He hopped on the broom, still invisible to the world and flew down to the streetlamp she was at. If she was a witch, her disappearance could have been explained as Apparition, but there were very few witches and wizards that dressed as muggles, and even fewer who would chance performing magic in front of muggles.

So, she was most likely a muggle criminal who had somehow orchestrated that man's death. As an Auror, he had no business dealing with muggle criminals. Surely she would be caught by the muggle police soon. Surely she was just some ordinary muggle criminal and not… what? The next Dark Lord? Harry shook his head to rid himself of the thought. It wouldn't do to see potential Dark Lords everywhere, making up enemies for him to fight. Still, with all this dark magic in the air, he would at least be on the alert for her, include her in his report as… a suspicious bystander? Yes, the strange and suspicious blonde bystander.

Well, that's where I'm going to end the chapter. I wanted to use this chapter to show the world I was creating and how things were going to fit together. Most chapters will be little snippets from each character like this. With 3 different fandoms going on, if I spent a whole chapter with one person, we'd start losing touch with them at some point.

So how'd you think of it so far? I have a lot of schemes in place and so do these characters! Next chapter, we'll see what Emma's been up to now that she's the Dark One, take a look into what Elaine's thinking (some of you might figure out who she is), and I don't know who the last one will be. Maybe Merlin again, maybe I'll make the other 2 longer, I'll see how it goes.

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