A/N: Let me start off by saying: This was supposed to be short. Very, very short. Then…well, something happened.

Also important: Those were all really believed to be uses of dragon's blood in history. You don't know what that means yet, but you will soon enough. Assuming you keep reading (hint, hint). Though when real alchemy referred to dragon's blood, it was talking about the red resin of several species of plant, and there are a hell of a lot more uses than what I listed.

Please enjoy and tell me what you think!

The Problem With Crossovers…

Everyone agreed that it was really too bad about the weather. The great sheets of rain pouring from the skies had ruined the first years' first looks at the majestic castle. But, Hermione pointed out, it did give the Great Hall a good deal of ambiance.

Just when the Start of Term Feast was in full swing—as tradition dictates—an interesting diversion occurred. More to the point, two figures in rain-drenched, black cloaks made their dramatic entrance to the Great Hall with a spectacular bang of the double doors hitting the wall.

Harry sighed and put down the ladle for the tomato soup. It never failed.

"Gentlemen," Dumbledore greeted as he stood from his seat at the head table, "What can I do for you this fine evening?"

"Are you really an alchemist?" One of the two figures demanded in a young voice. Dumbledore simply blinked at the rude tone.

The other lowered his hood, revealing the face of a boy in his middling teens. He shook his bangs free of water and then gave the room at large a warm smile. "I'm sorry for my brother's rudeness, sir, but it's very important. Did you really get alchemy to work in this world?"

Dumbledore, eyes a-twinkle, inquired, "This world, you said?"

The boy winced, and his supposed brother elbowed him in the ribs before lowering his own hood. The face revealed was indeed quite similar to the other stranger's; both blond and golden eyed, with sharp, straight noses and high cheekbones.

The slighter of the two sighed and repeated, "So, are you an alchemist or not?"

Dumbledore, ever the gracious host, conceded, "Indeed. I am even credited with the discovery of the twelve uses of Dragon's blood."

The long haired boy rolled his eyes and corrected, "You mean thirteen uses."

"Yes, I—" Dumbledore stopped mid-word and screwed up his eyes in thought. "…What?"

The boy, who his younger brother would identify as Edward, stared at the headmaster strangely. "You said twelve. But there're thirteen."

For the first time in decades, Dumbledore found himself quite speechless.

Edward frowned at the man. "Look, I know we haven't been exposed to the stuff for long, but a few rudimentary experiments and transmutations will get you that far." He scratched his chin speculatively, "Actually, considering how unstable and caustic that stuff is, there's probably loads more we could find if we had the time…" he shook off the thought. They had more important things to do than play with new organic suspensions!

Alphonse, the more even tempered of the pair, scratched the back of his head sheepishly during the long, uncomfortable silence that ensued. "You know," he said encouragingly, "Simple stuff, really." When no one volunteered anything but Dumbledore continued to stare inquisitively, he cleared his throat and started counting on his fingers, "Depending on how it's prepared it serves as an oven cleaner, a poison bringing instant death, a red wood varnish—"

"Don't know who thought of that one," Ed muttered.

Al continued as if he hadn't been interrupted, "A potion for gaining wisdom and courage, or granting superhuman strength—"

"For a few minutes," Ed allowed.

"It can be used to melt metals, as a blood coagulant, or for lowering fevers, or a potion to teach the languages of birds—"

"Though why anyone would want to learn, I don't know," Ed put in. "They never shut up."

Al, long used to his brother's quirks, just kept listing, "Taken orally, it works wonders on ulcers. Or to fight respiratory diseases. It cleanses an area of negative energy, and it works as a cure for blindness."

"And isn't it lucky we found that one?" Ed said, rubbing at his left eye.

Dumbledore's mouth open as if to speak, then closed again. Opened, closed. Finally he said, "The first twelve, right enough. But… are you quite sure about that last one?"

"Yeah, we—what?" Ed asked, "Oh, come on! You only need a six layer array to start to notice the effects."

"You can make six layer arrays?" the headmaster exclaimed, delighted, "I've never heard of one past four!"

The boy stared blankly for a moment before throwing up his arms and declaring, "You're no use at all! If you can't even do that, I don't know what good you could possibly be."

"I'm sorry to hear that, my boy." The old man said gently, "But alchemy is an ancient art. Perhaps one of the castles many ghosts—who are far older than I—would be of more use to you?"

"Huh?" Ed said blankly. "What ghost?" The half dozen specters floating around the room turned to stare at the short boy strangely.

"Hold on," Al demanded, "There's a ghost here?"

Ed snorted, "Of course there's not a ghost, Al. Don't be stupid."

"Don't be daft, boy," A greasy man with a crooked nose sneered down from his spot at the head table, "If you couldn't even see a ghost, the castle's muggle wards wouldn't have allowed you to find this place."

"I don't like your attitude, bastard. And what the hell's a 'muggle ward'?" Ed demanded.

Around the hall, a low murmur went up. Who didn't know what a muggle ward was? Most of the first year muggleborns probably knew already!

Professor Flitwick, a tiny man who had gone unnoticed by the brothers until then, explained, "Well, they…keep out muggles." When neither brother looked the least enlightened he continued, "You know, confuse non-magic folk and make them feel they should be somewhere else?"

Al's face screwed up in confusion. "Magic…?"

"I don't think something like that would work. We're pretty damn hard to distract when we're pursuing a goal," Edward said mulishly.

"But this was an empty lead," Al pointed out faintly from Ed's side, a distant look coming over his face.

"Yeah, I guess," Edward sighed with disappointment.

Alphonse blinked, eyes suddenly worried, "Brother… Did we have a meeting with the Colonel scheduled today?" He gasped, "I think we're late!"

Edward stared at his brother strangely, concern leaking into his eyes, "Al…The Colonel's not even on this side of the Gate. And even if…." The statement was left half finished as Ed trailed off, his eyes dulling, before starting again as if his last statement had never even been a distant thought.

"Yeah, I think we are late. But first, all of a sudden, I really need to find a loo." Ed blinked, "Which I guess is a bathroom—No, wait…" His eyes narrowed contemplatively, "No, I should definitely find a loo."

"Okay," Al allowed, "but I'm getting a craving for some blood sausage." Al started forward, then paused and turned to the other boy to ask, "Brother, what's blood sausage?"

"I don't know," Ed said thoughtfully, "But we should definitely get some. Right after I find that loo."

With a nearly audible pop of his neck, Al's head jerked to the right. "No," he dismissed, "now I want to run in that direction."

Ed turned to see where Al was pointing, then smiled an odd little smile, "Oh, good idea. Let's race!" The older boy tilted his head and looked around, "But why are we in these ruins?"

"I…don't know. How did we get here again?"

Ed shrugged distractedly as an awed look bloomed on his face. "Al!" He called breathlessly, "Al, look! It's a distraction." A beat. "Let's chase it!" And the boy took off running out the door.

"Where?" The younger blond yelped, hot on his brother's heels. "Where is it? I wanna catch it!"

There was a long, awkward silence in the Great Hall.

"Well…" Dumbledore began brightly, "Time to tuck back in!"

Down at the Gryffindor table, Ron Weasely shook his head sadly and sighed as he spooned himself more potatoes. "I swear this place gets madder every bloody year."

The Problem With Crossovers…Everyone Always Assumes All Main Characters Have Magic.

Second on the list…Dumbledore Doesn't Know Everything.

And you can throw in alchemy being different in different worlds, though it's less universal.