Title: The Twilight Border

Rating: T (for now)

Genres: Adventure/Angst

Full Summary: After his attempt to escape Gluttony's fake Doors of Truth, Ed finds himself on a strange new side of the real Doors. Having never resigned himself to not being able to get back, he goes about his research in the best way he can, as an alchemy teacher at a school that's more than ordinary. But it's not as simple as just continuing on. The boundary that the Doors created for him is failing, and the nightmares from his past, which he had just convinced himself were only nightmares, are coming back for him. What sort of a resolution will be found in the twilight border between worlds? Crossover.

Author's Note: This is probably the most complete idea I've had for a Fullmetal Alchemist crossover story yet. I've gone through idea after idea, but had no luck with them. Hmm. Well, let's hope for better luck with this one!

Timeline-wise, this starts right after chapter… 53 or 54 of the Fullmetal Alchemist manga, and is AU from there out. In Harry Potter, it's mostly compliant to Order of the Phoenix (book 5), right up until the end.

Chapter 1: No World For Strangers

-

-

"…This is part of the Xerxes ruins. These things are inside Gluttony…" The blonde turned to glare over his shoulder at the monstrous dragon-like creature that was Envy's true form. "To get rid of the evidence, right?" he accused. "I'm starting to understand what you bastards did at Xerxes."

-

"… These are all the pieces I can find." Envy nudged another piece of the fractured stone into the glow of the torch that Ling clutched.

The Xingese prince held the torch closer to the stone as Ed bent down to examine the writing. "So these are all parts of the Xerxes ruins?" he queried.

Ed nodded. "Yeah. This is the mural of the temple," he said. Mentally, he was comparing it to the transmutation circle he had seen back in the Fifth Laboratory, but he knew that it wasn't quite the same.

-

He had figured it out – they would escape from Gluttony by way of human transmutation. Ed was totally confident in his theory, in spite of the fact that it was only that: a theory. He understood what had happened in Xerxes, and overall he might think that this was a huge success, that it put him closer to the Stone than he had been… but all he wanted, right at that moment, was to be out of there.

Envy's tongue was hanging out, a disgusting sight in and of itself, but made worse by Ed's newfound knowledge of how his true form had come around. But a moment later, he had put his hands together, and the handmade circle was glowing with alchemical energy.

"Long time no see," Ed whispered as he sunk into the grasp of the Doors' reaching fingers.

-

Ed knew, unconsciously, that such a simple plan wouldn't work out properly. He knew it when he pressed his hands to the circle, he knew it when he found himself in front of Al's body, he knew it when he was drug bodily by the tiny, grabbing hands through a different door. He particularly knew it when he felt the gravity rotate, from pulling him down to pulling him onto his back… and he knew it most when he could see a cloudy sky, gray with the promise of rain, laid over with a gigantic golden echo of the circle that he had used to escape with Envy and Ling from Gluttony's fake Doors of Truth.

To Ed, it was as if his gravity was reduced, he thought, or time just seemed slower – as he fell, long and slow, to the ground that he didn't dare look over his shoulder to see. But when he landed heavily on the hard ground, time came rushing back at full speed. He was sore, he knew, from both his arm (the splint that Ling had so thoughtfully made was broken now), and from the hard landing – he had caught his back on something solid, and it had flipped him over on the way down, so now he was lying on his side. His vision was so blurry, and he thought for a moment that he would cough up blood, but the impulse passed quickly. Ed could hear people's voices, whispering in a worried and gossipy fashion, though actually hearing and understanding the words was beyond him at that point.

As he struggled to his hands and knees, trying to lift his head in order to get a look at his location, he felt the cough come upon him again, and this time he did as his body insisted, bringing up the crimson stuff that splattered horribly on what he could barely see was a street, paved roughly with irregularly-shaped gray stones. But it was the last thing he saw before he passed out, landing awkwardly on his injured wrist as he collapsed.

-

When Ed hauled himself forcefully from his barely-there slumber, his first thought was that his wrist no longer hurt. He raised his left hand, staring at it through blurry eyes. He could see little, but knew that he wasn't wearing his long-sleeve shirt or gloves. And that meant that somebody who didn't need to, now knew about his automail. With a sigh, the older Elric let his eyes close. Something really didn't work, he thought. Envy and Ling weren't there… I wonder if they got through, and I got lost somehow. That's the only solution…

After a few moments, he heard people speaking about him. Or so he assumed, judging from how the conversation progressed.

"I understand your concern, Minerva. But this person, whoever he is, has skill. I'm not sure where he came from, or why we didn't find him before, but he's here now."

"But Albus! I understand that you try to be trusting and open-minded, but this is just too much. A boy appears in Diagon Alley, not two months after you-know-who is back, and you say he's got magic. So you want to invite him to the school? I must protest!"

Ed's mind was immediately set to grappling with what she had said. Somebody whom he was supposed to know (but didn't) was back, he supposedly had 'magic,' and then these two were talking about a school. It was more than enough to make any self-respecting alchemist like himself say, what?!

"Protest all you like. I've my mind made up, and I am still the Headmaster. Besides, I can't tell how old he is – he'd be short for an eighteen-year-old, but if that's indeed the case, then my offer is null. You know that."

Short—Why they… The blonde's metal hand clenched tightly enough in the thin white sheets to potentially tear them, but he knew discretion, and let go as soon as he felt the ripping-force strain. I'm not eighteen… for crying out loud, what are they talking about?

"I do know that. Very well, since I can't stop you… But understand, Headmaster, that I in no way condone this choice of action."

At that moment, Ed heard one pair of footsteps approaching him, though he still couldn't see clearly enough to tell who it was; the man or the woman. So he simply slid back into the bed a little, and closed his eyes, setting his breathing to make it seem like he was asleep.

The person wasn't fooled. They stopped at the edge of his bed, and leaned over him – Ed's eyelids twitched slightly as their shadow fell over him – and said, "I know you're awake." That revealed that it was indeed the man.

Having had his bluff called, Ed opened his eyes sheepishly and sat up. He stared, eyes opened wide, at the person – he could only make out very vague colors. A skin tone here, white there (a very long beard perhaps?), and a generally cone-shaped amount of blue. Everything else was brown and gray, but Ed thought that that was part of the room. "Who are you?" he asked warily.

"My name is Albus Dumbledore," the man said cheerily. The top part of the blue cone tilted sideways, suggesting that the man had cocked his head in that direction. "May I ask your name?"

Ed frowned, and turned to squinting in an attempt to clear the image of the man. It worked only marginally – he could see that there were silver splotches on the blue. But it hurt his eyes, looking through his eyelashes like that, so he quit. "It's Edward Elric," he said. "Uh, look, where am I exactly? I kinda… got lost."

Albus's voice had a general twinkle about it as he said, "You're in London, England. More specifically, in the inn by the name of the Leaky Cauldron, right off Diagon Alley."

"… I've never heard of any of that," the alchemist grumbled. "How far is it to Central?"

"I've lived in England for longer than you would probably guess, and I don't know of any place in the world that's called Central. Are you sure that's the name of the place?"

That just confirms it, Ed thought. I'm in a much different place than just another part of Amestris. Even Ling, coming straight from Xing, knew Central. I'd guess that the people in Drachma do, too, though I've never been there. "Do you even know where Amestris is?" he asked wearily, just for good measure.

"No," was the completely not-a-surprise answer he received. "You do speak with a mostly German accent; maybe it's from a part of Germany where I haven't been. It's a fairly good-sized country, after all."

This only served to tick Ed off. "I don't know what Germany is, either. Geez, looks like I ended up even further off the mark." He mumbled to himself, "How many places can the Doors lead to?"

Ed didn't suppose that Albus heard him, judging from what the old man said next. "Well, regardless of where you are from! It seems to me that you are in possession of an ability that we here call magic. If you don't mind me asking, Edward, what do you know of magic?"

"That it doesn't exist," Ed responded bluntly. "What kind of joke is that? It's not even funny. 'Magic,' there's no way something like that could exist. Everything is explainable by science." He blinked a couple times, and then scowled. How annoying was this – he still couldn't see. He lifted his automail hand in front of his face. When it was within two inches of his face he could see it clearly, but any further away and it was blurry again. He felt his head begin to ache from changing the focus of his eyes so many times over again.

Albus seemed to notice the youth's headache-inducing attempts to clear his vision. "Well, since you seem rather set on your way of thinking, I suppose we had better first go to Diagon Alley and buy you some glasses. It seems like your vision is a little worse than you're used to, Edward, my boy." He chuckled slightly at the face Ed pulled.

"I don't need glasses," the alchemist said grumpily. "This is just because I hit my head yesterday. I'll get all healed – no idea how my arm got fixed overnight – and then I'll be able to tell you what color your eyes are right at the edge from the other side of the train station." But he rolled out of bed regardless, his will to see stronger than his pride at that time. "So, what'd you do with my clothes?" He stared down at himself, in his boxers and undershirt.

Again with the chuckle, and mister pointy-blue-coney-shape bent slightly, picking up the neatly-folded stack of cloth that was, indeed, Ed's outfit. "I got it cleaned for you," he said hospitably. "It was quite bloody, if you get my drift. I doubt that much of it was actually yours, since my healer-in-chief didn't find it necessary to give you a blood replenishing potion."

With a glare, Ed snatched up his clothes, and hurriedly got dressed. This not being able to see was, frankly, humiliating. The faster his eyesight was back up to par, the better.

-

Ed was frustrated. Here he was, walking through a brand spanking new, completely unfamiliar place, and he couldn't see an inch of it. All he could do was follow almost blindly behind the odd person wearing blue robes with silver stars (he was walking close enough behind Albus now to recognize the shape), until they came to a shop. The sign had white letters and a black shape on it, none of which Ed could in any way distinguish.

They stepped inside, and Ed didn't even glance up; just kept his eyes on the floor, and the hem of Albus's robe. He heard the elderly man talking with the store owner, though he evidently wasn't included in the conversation.

"… young man needs glasses."

"He attending Hogwarts?"

"We have yet to see that, but he does have the ability, whether he chooses to or not."

"Alright then. May I?"

"Go ahead, sir!"

Ed looked up as the owner stepped up to him. He was taller than Ed – but it's not like that wasn't a surprise, was this a country of giants or something? – and as far as Ed could tell, had brown hair, and didn't wear glasses. The blonde wasn't sure why he had assumed that this stranger would wear glasses, but assume he had, so it served to set him off a little.

The man's speech told Ed that he was smiling. "So, young man, I'm going to perform a spell now to figure out exactly what your prescription should be. Is that alright with you?"

Ed just shrugged, and said rather frumpily, "Fine. Convince me that this isn't a hoax." He folded his now-gloved hands over his chest, quite determined to figure out the trick that this man would try to use.

But all that happened was that he suddenly found a wooden stick in his face – it made him jump slightly – and waved it in several quick, tight circles, muttering a word that Ed couldn't rightly hear, and guessed that it wasn't in whatever the name was for the language he was currently speaking (nobody had worried about that in Amestris, since there really was only one language). Ed didn't feel anything, and was about to say something degrading to match, but the man cut off that plan by making a pleased noise and rushing off.

It wasn't five minutes later before the man came running back. "Alright," he said happily, "Now all that's left is to pick out the frames!" He grabbed Ed's arm (the flesh one, luckily), and pulled him over to one end of the shop. Ed leaned in, and could make out rows and columns of metal frames, in every shape and color he could think of to make glasses in, as well as several he couldn't (how many points did those star-shaped glasses have, now?). He picked out the first pair he found, and set them on his nose rebelliously.

Albus had come over at that point, and Ed turned to face him, looking for his opinion, since it wasn't like he'd be able to make a decision looking in the mirror at himself. From the movement of the Headmaster's pointed hat – as Ed had reasoned it was – he disapproved. "Too wide across," he said, "And definitely not a complimenting shape." Ed promptly set them back on the hook – he agreed completely.

"Try something rectangular," the shop owner suggested, and turned to the wall. He reached out seemingly at random, and pulled a pair off. They were smaller than the ones Ed had tried on first, and he felt a jab of annoyance and squashed the desire to say to the shop owner, are you suggesting by giving me small glasses that I'm smaller than average, and just put the frames on his face.

This time, he immediately felt more comfortable with them – they weren't weighing down on his nose, and fit in the right place, like the others hadn't. The other two immediately agreed that they were right, after getting a good look. Ed took them off his face and examined the frames closely. They were silver, and rectangular, with well-squared sides. The top of the frame was left unclosed, so the glass would be exposed there.

Albus agreed to pay for the frames, and anything else that Ed may need for that matter, since Ed didn't have any money here (and they both agreed that it wouldn't go well if he asked somebody to withdraw from an account that didn't exist). The shop owner only took a couple minutes to fix up the glass, and when Ed set the frames on his face again, he was surprised that they were very little heavier, and the glass was thin, in spite of the strong prescription he knew he must have required. When he raised a questioning eyebrow at the shopkeeper, he grinned secretively and said, "Magic."

As soon as Ed walked outside, he found himself in the middle of the culture shock that he had been waiting for to catch up with him. All around him, people in robes and pointed hats of every color and variety were walking, talking, shopping, socializing, gossiping, casting spells, and generally acting like a community built on (completely illogical) magic. He was glad that he could now read the names on the shops, since they told him a surprisingly large amount about the place. Directly across from him, he could see a tall, wobbly-looking building, which claimed to be called Gringott's. He wondered about it – the architecture seemed much different than the higgledy-piggledy shops that the rest of Diagon Alley consisted of. When asked, Albus said that it was a bank, run by the goblins who had built it themselves.

The duo found their way quickly back to the Leaky Cauldron, where this time Ed got to take a good look as Albus opened the brick wall. It fascinated him, the way the bricks slid around and rearranged themselves so smoothly. He could have gotten the same effect with alchemy, but it wouldn't be nearly so smooth or showy; it would be the normal alchemy, with the flow more like some viscous substance than giving the objects their own life and movement.

For the most part, Ed found it most convenient to ignore the generally dim, less-than-outstanding conditions of the inn as he walked through the pub downstairs, concentrating more on whether or not he accepted the idea of magic. He had seen undeniable proof – now possessed some of that proof sitting on the bridge of his nose – but in spite of that, could he believe something that would, potentially, disprove his whole life's truth? Equivalent exchange demanded that he offer this strange Headmaster something for giving him such quality glasses – he had taken a peek at the money that Albus had handed over, even though the old man tried to conceal it with his sleeves, and no matter the monetary system, that much gold was never worth a small amount. Would equivalent exchange come out to willingly acknowledging magic, and the implications that came with it?

Back in the room that he assumed was 'his' for the time being, he sunk onto the bed to think those same thoughts. When Albus said to him casually, 'a penny for his thoughts,' he supposed that he might as well speak up.

"… I'm an alchemist," he said plainly. "My entire life has been led believing in equivalent exchange, and has been bound by the laws of alchemy and equivalent exchange. Magic… from what I've seen of it… obeys less than half of the laws, and from what little I've seen, doesn't even make sense by equivalent exchange. I suppose you could understand why I'm wary of this. If I believe in this, and it's not true, where does that leave me?"

Albus nodded understandingly, ice blue eyes twinkling with a strange satisfaction, and Ed continued blandly. "I'm considered one of the greatest alchemists in a long, long time. I've fought monsters created by alchemy; committed the greatest sin you can in my culture, with alchemy; and it was alchemy that, for five years of my life, I intended to use to rectify what happened in that mistake. I haven't succeeded yet. I don't know hardly anything about magic, but if it has a chance of doing what I haven't found a way to do with alchemy yet, then I'm at least willing to give it a shot."

He sighed, and fell back on the bed, eyes closed, twirling his glasses with one hand. "That said, I really don't want to be a student, in any condition," he said airily. "I don't suppose you can come up with some insight on that, mister Albus Dumbledore, Headmaster of some school which I haven't heard the name of yet?"

Ed supposed that he might find that perpetual glimmer in the old man's eye to be aggravating, if it wasn't working with him at that moment in time. "I believe I can," Albus stated gleefully. "You say that you're a great alchemist, and I believe you; my boy, you don't seem like someone who would brag so calmly. So here is my proposition. I formally invite you, Edward Elric, to come to Hogwarts School of Witchcraft and Wizardry, to teach a new subject there: Alchemy."

Promptly, the blonde teenager sat up, all of his hyper attention and eagerness standing on end. "Well, I didn't expect that," he said, satisfied. "A teacher, huh? Well, I daresay I taught Al half of what he knows," that much was probably a brag, "and they do say that the best way to learn something is to teach it. I completely accept!"

"Then welcome to Hogwarts, Professor Elric," Albus said, extending his hand. Ed took it with his automail one, and they shook on it.

As they say, out with the old and in with the new; Edward Elric, the Fullmetal Alchemist, had just been kicked to the curb temporarily, replaced for the time being with Edward Elric, professor of alchemy at Hogwarts School of Witchcraft and Wizardry.

Disclaimer: I don't own anything relating to Harry Potter or Fullmetal Alchemist, except my own copies of the Fullmetal Alchemist volumes and my copies of the Harry Potter books and movies.