Author's Note: Written for prompt 110, "Switch," at the FMA fanfic contest. Accompanying artwork can also be found on my LJ. I was initially debating whether to include this in Ex Fato Familia, but ultimately realized that anyone with a sibling has had a moment like this.

Thanks again to my wonderful beta, Sapidus, for both his fresh eyes and the enormous stack of D&D books he's entrusted to my care. Seriously, dude. Come pick them up.

Winry snapped her pencil in two.

"-tomail, my one and only love…!"

Her head whipped toward the door of the overnight patients' room. An exaggerated squeal and a burst of tinny snorting carried clear across the workshop, causing heads among the midday crowd to turn. The overblown falsetto was Ed's, unmistakable and ear-splitting.

It was also, apparently, louder than he anticipated.

"…smell the machine oil! Ooo, I'm Winry Rockbell and I LOVE AUTOMAIL SOOOO MUCH."

Winry stood, brows drawn low as a livid heat rose in her cheeks. Al's furious attempts to shush his brother between fits of choked laughter carried as clearly as Ed's voice through the thin door. Mr. Garfiel glanced over at his apprentice, eyeing her hand suspiciously as she lowered the remains of her pencil and slid her fingers around her wrench.

"Winry, sweetheart," he said, raising an eyebrow as she began to stalk in the opposite direction of the room where the Elrics were waiting. Every eye in the shop followed her. "Where are you going?"

She glanced back over her shoulder, a devilish grin spreading over her face. "Two can play this game."

A well-timed kick to the door cut short the shrieking laughter. Winry thrust a finger out accusingly, and the light glinted off the steel fastened to her arm.

"DID SOMEONE CALL FOR A GUY SO SHORT HE COULD SKI ON A PAIR OF TOOTHPICKS?" she demanded.

Dumb silence followed as the boys stared. Her hair was pulled back in a low braid, her normal pants swapped out for an oversized black pair, and Ed's coat hung over her shoulders. The crowning glory – a hollow automail arm that she had been using as a machining model – was strapped to her shoulder.

That's right, she thought, a thoroughly Ed-like smirk splitting her face. Go on and stare.

It was only after several unresponsive moments that she noticed Ed.

His hair was unbraided, pulled up in a ponytail high on the back of his head. That, in and of itself, wasn't abnormal – but his shirt, rolled up to his chest to expose his abdomen, was. So was the hem of his pants, rolled down around his waist in a crude imitation of her jumpsuits, and the wrench he held over his head, arms frozen mid-flail.

The silence, if possible, got even dumber.

Alphonse glanced frantically between the two, hands held up in self-defense. "Uh, Winry! We thought you were busy with customers toda-!"

The impact of a wrench sent Al's helmet flying.

Ed dove behind the couch, peeking up over the top as Al cried out and fumbled for his head. Winry's eyes flashed dangerously at both of them.

Ed laughed nervously and sank lower, never taking his eyes off the simmering mechanic who now clasped a second wrench – the one he had dropped in his bid to escape, he realized with a sinking feeling – dangerously at her side. His eyes darted between her face and the wrench. "Hah! Yep, you really got me good there, Winr-"

A flash of realization hit him, and his eyes shot open. "IS THAT MY COAT?"

The tiniest of smirks tugged at the corner of Winry's mouth. "Do you see any other midget-length coats in this shop?"

"WHO'RE YOU CALLING SO SHORT HE CAN USE THE CAT DOOR TO GET IN?"

"YOU, ALCHEMY-FREAK!"

"GEAR-HEAD!"

The crash of a second wrench nearly made Al fumble his helmet. He jammed it onto his shoulders and turned to see Ed crumpled on the floor. Winry loomed over him dangerously, eyes flashing like an electrical storm.

"SOME PEOPLE IN THIS SHOP ARE TRYING TO WORK!" she bellowed, and spun on her heels toward the door.

"Oh yeah?" Ed rose slowly to his feet, and extended his hands toward Winry. "Without these?"

Winry stopped in her tracks, and looked down at her pocket. With a start, she spun toward Ed. He grinned at her, a wrench in each hand.

"Give it BACK!" she yelled, face turning an unnatural shade of red.

Ed grinned wickedly. "Maybe you should watch your equipment better!" He inched back toward the window, and his head whipped toward his brother. "Al! Catch!"

Al yelped as Ed hurled a wrench at him. He pulled his hands back as if the tool were on fire, and it clanged to the floor as he withdrew toward the wall. "Brother, I'm not getting involved in this!"

Ed froze and swallowed. Winry was at Al's feet in a flash, looking up at him from under her bangs with a maniacal smile. "You're a good person, Al."

Al saw the panicked glare Ed shot at him. He read the meaning as surely as if it had been written on his forehead: Traitor!

Ed shrunk back as Winry stood, slowly, turning to face him. "Ed. Drop the wrench."

The alchemist's eyebrow twitched violently in the silent seconds that followed. Alphonse struggled to absorb the situation; Ed, with his shirt hitched ridiculously at his chest and the waist of his pants rolled down at the hips, and Winry, radiating waves of anger and stalking toward him with the most Ed-like stride Alphonse had ever seen.

Then, with matching screams and the slam of toppled furniture, they were gone.

Alphonse hesitated before stepping over the upset couch and sticking his head out into the hallway. Two blurs of motion were tearing through the workshop, leaving wide-eyed stares in their wake. It took less than a minute for Winry to have Ed darting out the door and into the street, taunting her over his shoulder.

A moment of stunned silence followed as Winry slammed the front door shut. The rest of the shop sat in stunned silence as a tornado of papers fluttered gently to the floor. Winry's shoulders heaved in a silent sigh, and for a moment, Al thought he saw a smile flit across her mouth.

The slightest twist of her head was all it took for Alphonse to yelp and lock his room behind him.