"Oof!"

Sam hit the ground hard. The force of Dean slamming into him was like a linebacker tackling, and he went rolling several feet as he hit the ground, his slim ten-year-old body unable to absorb the impact like an older kid could.

An older kid like Dean.

The room was pandemonium as Sam stared up to see his older brother going for his gun.

"You'll regret that, you bitch! " Dean snarled as he leveled the intricately carved silver colt at the witch that had appeared in their room.

Tall and elegant, harsh and cold, the woman merely smiled, raising her hand in tandem with Dean's. The moment they stopped moving together, Dean's finger tightening on the trigger, the room went white.

The last Sam saw before everything was overwhelmed in brightness was Dean's silhouette, black against the white and defiant to the end.

Then the light faded and Dean was gone.

"Dean! " Sam screamed, flipping over and scrambling to his feet. A faint ghost of his brother's silhouette in his eyes was all that was left of the teenager, and even that faded as Sam blinked away tears of fear and uncertainty, alone with the witch.

The woman slowly turned in place to face Sam, an unpleasant smile gracing her face as she raised her clawed hand. "You boys are a handful for such young humans," she breathed, stepping over something that lay crumpled on the ground, like the shredded remains of Dean's shirt…

Sam blinked, unable to believe his eyes.

It wasn't a shirt.

No shirt they, or anyone, owned would have such precise plaid markings, and it certainly wouldn't have the smallest arm Sam had ever seen limply stretched out, such a familiar spike of dirty blond hair resting on the arm as though asleep…

The realization of what he was looking at crashed over Sam in bare seconds, and he pushed himself to his feet before the witch had finished her first step, charging her legs.

As Sam recklessly tossed himself at the ground, the locked and latched door of the Trails West room they were staying at slammed open, the hinges in splinters from the force John Winchester hit them with. He stood there, shadowed by the bright sunlight outside, assessing the room in a flash.

"Sammy get down!" John thundered as he brought his gun to bear on the woman.

"No, Dean needs me!" Sam protested, squirming through the witch's legs.

There was no time to explain himself as she whirled around. A hand closed around the collar of Sam's jacket and hauled him up from the ground.

But not before his hands scooped under the doll-sized version of his older brother and brought Dean along with them.

Sam was only dangling in midair for seconds before the roar of a gun filled the room and he was falling.

He landed on his front with a grunt, unable to catch his balance with Dean precariously cradled in his hands. It took all of Sam's effort to not tighten his grip on the slim, vulnerable body of his older brother in his care.

This was all wrong. Dean should never be vulnerable!

Then, a hand clamped around Sam's arm. He cried out, belatedly realizing it was John and not the witch. "Let's go!" John snapped, his gun panning around the room as he searched for the witch. During Sam's moment of inattention as he fell, she had vanished into thin air.

Sam had no response, stumbling along behind his dad and carried by the older man's force. All he could do was stare down at Dean's limp body, see the tiny head loll to the side as Sam was dragged out of there by their father.

"Dean," he whispered, a teardrop falling at last only to land on Dean's shirt and drench him.

"What happened in there?" John demanded as he gunned the Impala, aiming for the highway.

Sam shook his head, Dean held close to his chest like an anchor. "I- I don't know," he blurted in shame, feeling his ears turn red. He had no idea what had happened, but he knew that if Dean hadn't shoved him out of the way, that spell would have hit him instead.

So small. Sam brushed a finger down one of Dean's tiny arms, marveling at how soft the normally thick jacket was. Then, he lifted his older brother up, hesitantly leaning an ear over Dean as he realized he had no idea if his brother was even alive after that attack.

"What's the matter?" John asked, his voice lowering as the adrenaline from the fight began to wear off. It wasn't lost to him that Dean was missing, and Sam was acting strange, but he needed to get his youngest as far from her as he could before he considered any other course of action.

Sam was silent, holding his breath as he listened carefully. There, just at the edge of hearing. A soft sound of a tiny breath. Sam pulled his hand away from his ear, and then held out his hand with reluctance so John could see what he was holding.

The car jerked to the side when John caught sight of just what was in Sam's hand. Another car roared past, horns blaring and lights flashing. Sam clutched Dean close to his chest, paranoid that Dean might be sent flying by the car's erratic motions.

A minute later, they were parked on the side of the road with the four ways on. John stared blankly into the distance. He hadn't said a word since Sam held Dean out to him.

Sam busied himself making sure his older brother didn't look uncomfortable. This mostly meant he carefully nudged Dean to the center of his palm, letting his head rest on a cushion of skin and assuring that none of his arms or legs looked like they'd twisted into an uncomfortable position.

It was painful for Sam to realize that for all he knew, Dean had broken bones from the fight. He was so small.

John took a deep breath, startling Sam from his older brother. Their eyes met.

"Sam," John said slowly. "Is that who I think it is?"

Sam nodded, blinking rapidly. "He… he pushed me out of the way of her attack," he mumbled, looking down at Dean. "Then…" Sam trailed off, having a hard time continuing.

John held out a hand. "Let me see."

Sam held Dean closer. "But… he might get hurt if we move him too much," he said.

John sighed, leaning over so he could take a better look. "Just… hold him out for me."

Extending his hands, Sam kept them cupped as though he held the most precious gem in the world. John looked over his older son, his brown eyes intent as his brow furrowed. He reached forward and nudged Dean's hand. The colt Dean had tried to defend himself with slid onto Sam's palm, a small speck of silver against Sam's palm. It might as well be a toy.

Sam wasn't the only one who looked terrified at the realization that Dean would be helpless on his own.

"He's breathing," Sam said. Dean was the one who'd taught him what to check if he ever found someone passed out. Since he was too big to take Dean's pulse, it had only left him one option. "But he hasn't moved since that lady attacked. The room got bright, and I couldn't see anything, and when it stopped, Dean had fallen to the ground."

He looked down. "This size."

John swallowed. "Right. Don't worry, Sam. We'll figure this out and get him back to normal. We're just gonna take a trip to Bobby's to get some backup.

"Keep an eye on Dean for me, will ya?"

After John finished checking Dean, the rest of the drive was silent. The radio was turned off, and the hunter often glanced in his rearview mirror. They took more turns than Sam remembered, and the trip to Bobby's was over two hours longer than it should have been, but he didn't care. He couldn't look away from Dean.

At one point, he was worried his hands were growing clammy. He fidgeted in place, until he saw how much each movement was affecting Dean where he lay prone. That was enough to make Sam freeze back up.

As the drive went on and the initial panic and fear began to wear off, Sam grew fascinated by the sight of Dean. Every detail was precise and perfect. If Sam squinted, he could make out a near-microscopic amulet resting on his older brother's chest. If he stayed like that long enough, he could actually make out the slight motion of Dean's chest as he breathed in and out in a steady rhythm, as though he was just asleep, no matter that gentle nudges to his shoulder had no effect.

Dean slept on.

When they reached Bobby Singer's home in Sioux Falls, South Dakota, Sam was bustled out of the car. John grabbed all the remaining supplies that hadn't been left behind in that motel room during the attack. Sam walked slowly to the front door, each step taken with a cautious gravity and focus that he didn't normally show. Usually he would have run on ahead, eager to greet Bobby and see what new cars were at the salvage yard out back.

"Hey, Bobby," John greeted as the door opened. One hand on Sam's shoulder, he guided his youngest into the house as Bobby stepped back to admit them, picking up John's mood just from the tone of voice. "We've got a problem."

The reveal of Dean to Bobby went as well as could be expected. His face turned white as he saw where the teenager lay. Sam looked up at him, hopeful that Bobby would give him a reassurance that he knew what was happening, that they would fix Dean and this would all be over and Sam would be back to looking up at his older brother.

Reassurance never came. Sam found himself sitting at the kitchen table with a hotdog left nearby and a puddle of ketchup while John pulled Bobby aside to talk where Sam couldn't hear them.

Sam caught a few scattered phrases as he sat there, unhappily spearing the hotdog with a fork and wishing someone had thought to put it all on a bun. He didn't want to risk doing too much so long as Dean was in his hand, and so far he hadn't thought of a way to put him down.

"-can't risk him-"

"There's no way Dean would-"

Sam chewed slowly, every sense in him tuned towards the hall by the kitchen. The voices were hushed and urgent. Things were bad. Bobby was never this upset.

"-never saw this before."

By the time he finished his food, Bobby came back into the room and the front door slammed shut as John stormed out. Bobby squatted down next to Sam, understanding in his clear blue eyes.

"Sam," he greeted evenly. "How you holdin' up?"

"I'm okay," Sam confirmed. His eyes fell. "But Dean-"

"Don't you worry about Dean," Bobby cut Sam off. "We're going to do everything we can to track that witch down and wring a cure out of her for what she did to him. You know no one can mess with your Dad when he's on a mission."

Sam nodded. "He can be scary when he's on cases."

"Right, but he's scary for the monsters, not for us," Bobby said with a smile. "What we need you to do is keep a close eye on Dean for us. Once I call up some friends of mine, we're going to head back to Haven. You remember how to shoot a colt?"

Sam's eyes were wide as Bobby held out a gun. It was older than Dean's, now resting in Sam's breast pocket so they didn't lose it, but there was no doubt in his mind that it would work like new. Bobby knew weapons better than John and Dean together.

"Dean let me shoot his when we had time," Sam breathed. Bobby let him take the gun and he hurriedly put it on the table.

"It's for you to use if you need to protect yourself and Dean, and that's it," Bobby said. "Watch yourself, alright?"

He mussed Sam's hair, leaving the young boy alone at the table, staring between the gun and Dean.

"Dean, please wake up and be okay," Sam said quietly.

Throughout the next week, Sam waited at Bobby's place. John and Bobby stopped in every few days to check up on him, and a few other hunters Sam recognized from stays in South Dakota drifted by. Some to help his dad, some just needing access to Bobby's library on the supernatural.

Aside from John and Bobby, Sam was to keep Dean a secret from everyone. As far as any other hunter knew, the witch attacked the two boys in the motel room and now Dean was missing. Bobby didn't want to risk any overzealous hunter assuming Dean was now dangerous because of his curse and attacking the boys while they were on their own.

Sam did manage to find a place to put Dean where he wouldn't get hurt. He took the pillow from his bed and cautiously slid Dean onto the white cotton surface. There, Dean was cushioned from any sudden jolts, and Sam had both of his hands free. He debated about where to put the pillow for an hour before deciding to place it on the center of the bed and curl up on the floor next to it in all the blankets. It wasn't the best, but it would do. Sam didn't want to risk Dean stumbling off the pillow and falling onto a hard surface and maybe getting hurt.

Dean stayed with Sam wherever he went in the house. He was afraid to leave Dean on his own. Anything could be dangerous, and in the warm summer, there were more than enough bugs and rodents around to be hazardous to the smaller Winchester.

Sam barely noticed the time pass that week. All that mattered was his brother was okay. He hovered close by, always checking to see any sign that Dean was rousing. The longer he slept, the more Sam worried that he would never wake. The thought came to Sam on more than one occasion that the shrinking caused by the witch was a distraction and a way to keep them from taking him to the hospital to get proper care while he was in a coma.

Then, on the seventh day, things changed.

Sam slept peacefully on the floor, sprawled out in the collection of blankets he'd slowly amassed from throughout Bobby's house. There were enough in the room to almost coat the floor by the end of the week. It was a comfort to have a place to burrow. For so long, he could steal into Dean's bed if he got nervous and curl up for security.

Now, Sam was the bigger brother, and had no one else to look to while John and Bobby hunted the witch.

The night was cloying in the spare bedroom. Motes of dust floated in the little light that made its way through the only window in the room, moonlight illuminating the bookshelf across from where Sam rested. His breathing had long ago evened out into sleep.

This meant he missed the motion that happened up on the bed.

Dean woke with a start, his pulse surging with adrenaline as consciousness returned for the first time since the fight with the witch. He sprang to his feet-

-and immediately tumbled to the ground, landing on the cushioned surface with a frown.

None of this lessened the urgency in him. He needed to get out, find Sam, find John. That was it. Sam was in danger. He couldn't remember from what or who, but he knew his little brother needed help now.

Shifting so he was on his hands and knees, Dean crawled across the white surface, confused by how big it was. Surely there was an ending to this white cloud of-

His next hand landed on empty air, and Dean went tumbling head over heels down the rest of the pillow.

It felt like Dean fell down that slope forever, but in reality it was only a few drawn-out seconds before he landed with a start on a slightly firmer surface. The muffled curses that spilled out of Dean's mouth tapered off as he heard a sound in the distance. Like the steady breeze between the treetops, disrupted by the rush of an ocean.

Something was here with him, and from the sound of things, it was big.

Dean didn't waste any more time. As soon as he realized there was something horribly wrong in his world, he was on his feet and running, trying to squint to see his surroundings and attempting to put as much space between himself and the thing as he could.

"Dean?"

The voice that sounded out of the blackness made Dean trip over a fold in the strange surface he was running along, and he went sprawling. "Sammy?!" he called out, his heart lurching as he realized his little brother could be out there in the darkness, facing this thing on his own.

He stubbornly ignored the way Sam's voice warped around him, the deep sound so out of place coming from his scrawny little brother.

There had to be an explanation for everything, there just had to be.

Something shifted from the side again, and it sounded like an entire warehouse of fabric was moving. Dean pulled out his knife, edging to the side and scanning the ground around him. Gotta find Sammy and get out of here before it finds me.

"Dean, thank god you're okay."

"Sam where are you?" Dean called out, trying to zero in on his little brother's voice. It sounded like it was coming from the same place as the massive gusts, but that was impossible.

It had to be.

"I'm here."

Even the funhouse mirror style of Sam's voice was hushed as he spoke. The hairs on the back of Dean's neck rose. "What do you mean?"

A light snapped on, and Dean finally saw where he was.

Sam stared at Dean, and Dean stared right back at Sam.

It was like the world had frozen in that moment with the brothers' first view of each other.

Dean, standing alone on the bed. He was crouched in place, one hand clutching his silver knife and the other held out to keep his balance on the cushioned surface. Sam stood by the door of the room, his finger still on the light switch, his eyes wide at how little Dean was.

A week of seeing his older brother crumpled and limp had helped prepare him, but Dean had no such preparation.

One foot edged backwards, and then another. Dean backed away from the giant form of his little brother, his breathing quickening as he took it all in. The bed, the window, the size of the door. The light overhead that might as well be the sun for all the good he'd do trying to reach it.

And Sam…

"W-who are you?" Dean shouted up at the giant in the room with him. "Where's my little brother?"

Sam gulped, his eyes full of water. "It- It's me, Dean," he tried explaining. He took a step forward, planning on dropping to his knees to be back on the same level as Dean.

That was a bad idea. Dean leapt backwards at the step, almost falling on his ass when the bed didn't cooperate. The silver knife wavered, then his resolve strengthened. "No," Dean said firmly. "My brother's not a giant! "

Sam had no comeback, and let his hands drop to his sides. Dean took this as the time to glance around, quickly plotting out the room around him. Gotta find Sammy. So long as the giant in the room wasn't grabbing at him, maybe there was time…

Then, a noise made him stop. Was that… crying?

Dean forced himself to look at the giant he'd woken up to. The kid had sunk to the ground and had his face covered, shoulders shaking. The sound of him crying sent a dagger through Dean's heart, like he'd done it.

Before he knew what was happening, his legs carried him to the edge of the bed nearest Sam. That was when he realized that it was his little brother there, as insane as this fever dream was. Sam was upset because Dean was rejecting him.

"Sammy, hey," Dean said, his voice losing the icy edge from a minute ago. "It's okay. I'm here, it's gonna be okay."

Sam paused, peeking between his fingers. "You mean it?" he asked thickly.

Dean nodded. "Just like always. We'll figure it out. Whatever this insanity is."

Sam moved his hands down to his lap, staring at them as his fingers twitched with energy. His eyes were big and watery, but with a few gasping breaths, he started to come under control.

Dean forced a grin. "You've always got me watchin' your back," he promised, with no real idea what he was going to do now. Whatever had happened, he needed to look out for Sam, and he couldn't let his little brother down just because he wasn't so little anymore.

I know a bunch of you wanted more tiny Dean, and I'm pleased to present (maybe) the start of a new AU! (or two)

This is the reverse of Brothers Together, where Dean gets hit with the curse instead of Sam, but Sam still manages to rescue his older brother at the very last second.