Dean came round on the floor in the cellar to find himself in the arms of his brother.

Literally.

Sam was resting on the ground, and had pulled Dean onto his lap in a sitting position with his legs bent into an almost foetal position and his brother surrounding them with one arm while his other was wrapped around Dean's back, holding the smaller man in closely to his chest.

And he was talking to Dean, almost as if trying to soothe him: "It's okay, baby, it's okay. Are you hurt, baby? Anything broken? Oh, baby, it's okay." And to Dean's horror, his mouth was brushing against Dean's ear, his forehead, his jaw, his lips…

"Sam?" Dean spluttered and tried to pull away from the vice like grasp that he was in. "What's with you? You had a bang to the head?"

"Are you okay, baby? You're right, I shouldn't have made you come with me. I'm sorry, baby." And his mouth was again on Dean's, his tongue pressing through to meet the other man's.

"For….!" And Dean was pushing his brother away forcibly and struggling to get to his feet. Even as he hurried to move from his lap, Sam was helping him to stand by putting his large hands around Dean's waist and making sure he was stable on his feet. "Have you gone insane?" This was said with a hiss of extreme embarrassment.

"Dean? Are you alright?" Sam was getting to his feet as well, his hands still on Dean's hips as if they had been glued there. He looked down at the smaller man with concern. And love. Before Dean could react, he was pulling Dean tightly to him and kissing him with…an accustomed passion.

And Dean was trying to pull away from him but he just couldn't move: he was being held that tightly. He knew Sam was strong, but this seemed like… this was more than just Sam somehow. He did the only thing he could and kicked out as hard as he could, feeling a little guilty as Sam exclaimed and bit down on his own tongue in shock.

"Dean! What the hell!"

"What do you mean 'what the hell'? Sam, what are you on?"

They glared at each other in the darkness of the cellar. Dean recovered himself first, checked he still had his gun and looked for his flashlight on the ground. "What the hell was that glowing thing? And that burst of light? Where's my fucking torch gone?"

"Dean! Language! What's wrong with you?"

"Me?" But Dean had seen the shape on the ground of the light and moved to pick it up. Carefully he pressed the switch and to his relief, it turned on.

"Ugh! Turn that off! You trying to blind me?" Sam was gasping and covering his eyes. "Where did you get that from?"

"What?" But Dean was shining it in Sam's direction as he was speaking and realising that his brother's clothes had changed. "How are you wearing a suit?"

Sam paused from shielding his eyes from the painful brightness and stared at him. Then he took a deep inhale. And another. "Since when did you look so scruffy? And what's wrong with your scent? It's all but gone!"

He took a step towards Dean, but this time there was nothing friendly or loving in his expression. And Dean was fast coming to the conclusion as well, that there was something definitely wrong and he didn't want to be in this cellar with his little brother anymore.

Because he didn't think it was his brother.

But even as he began to back up, Sam, or not-Sam as the case seemed to be, was on him. Far faster than he had ever moved before, even when juiced up on demon blood. And he was strong, really strong. He picked Dean up by his neck as he were nothing and held him off his feet up against the stone wall, using his larger solid body to crowd the smaller man into submission.

Dean gasped for breath as he was crushed. "Sam!" It was an instinctive response.

"How do you know my name? What are you?" Now his brother's nose was buried into his neck and the larger man was inhaling so deeply that Dean could feel the suction against his skin. "And what have you done with my mate?"

"Wait…mate? I'm your mate?"

"You are nothing. Now tell me: where is Dean!"

"I don't know, I don't know!" Dean could feel his vision turning black: Sam was holding him too tight, he couldn't breathe. "Please! I and my brother were in this cellar, it looks exactly like this one. Then there was this thing that had a bright glow and I picked it up. And then I woke up here! I don't know how!" The last words were struggled out through a gasp as he lost the last of his air.

Then he was hitting the ground with a painful thud as Sam, or whatever this thing was that looked so like him, released him suddenly. Even as Dean lay dazed, desperately sucking in much needed oxygen, the other Sam was pushing him fully onto his back, straddling his chest and deliberately kneeling on his arms. Satisfied that Dean was pinned beneath him, he leant back on his heels and contemplated the smaller man.

"This is impossible. You look exactly like Dean: even your scent is the same, but much weaker. I can hardly smell it. Who are you and how did you do this?" His expression was serious and angry, and his hands were folded into fists and raised, ready to respond with serious violence to any explanation he didn't think was true.

"I didn't. And my name is Dean as well. Please believe me. I picked up this glowing thing…."

"So did my Dean. Or so he said he did. But I couldn't see it."

"Neither could my Sam! He asked what the hell I was talking about. So I picked it up to show him."

They stared at each other. Dean tried to shift beneath the other: the stone floor was uncomfortable and hard, as well as being cold on his back. Still Sam just studied him, with as much contempt showing on his face as if he were studying a bacteria on a laboratory slide.

Dean tried to calm himself down and think. "Somehow… I don't know how... But we've got swapped. Either you or me. So? Whose world are we in? Mine or yours?"

Still the other just stared at him in silence. Dean felt himself lose the use of his arms as the circulation was cut off beneath the bony knees, and knew it would be painful when the other finally did move. "Shall we go and see?" he suggested.

Then this Sam shook his head to brush his long hair back exactly as the real Sam did, and finally went to get up. "You stay."

Sensibly Dean did, waiting until the large feet had stepped back out of stamping range. But as he rolled over to get his legs beneath him, he was suddenly grabbed by the back of the neck and pulled upright to be shaken roughly. "You try anything, and I will break all your limbs, do you understand?"

Dean nodded and winced at the strength of the grip at the top of his back. Then he was being forced to walk across to the stairs by the other man, still with that painful grip on his neck with one hand, and the other hand now firmly wrapped around the bicep on his left arm. Dean stumbled in the near darkness and noticed that Sam didn't seem to be hampered in any way by it. In fact: hadn't he been surprised when he had seen Dean's flashlight? Come to that, where was it? Then he remembered that he had dropped it when Sam had nearly suffocated him.

"Wait." Dean tried to stop so he could look back. "I've left my…." His head hit the ground before he could finish his sentence and he could feel Sam's knee in the small of his back.

"What is it? What are you trying to do….?"

"My flashlight, that's all!" Dean gasped. "I just wanted to get my flashlight." But he was aware of the other man now rocking on his spine with his knee as if feeling something with it. He couldn't think of what it could be as all he could concentrate on was the pain that the action was causing him, because Sam was kneeling right on where his gun was tucked in to his jeans and making it dig hard into his back and….Oh shit!

Even as he registered what the other man had just realised, Sam was snatching the gun out with a growl of anger. And it was a growl: one that echoed around the vast space until Dean could feel it through his entire body. He felt a tremor of fear both from the anger that he could feel coursing through the other Sam and from his own gun suddenly being cocked and the muzzle pressed against his head.

"What the hell is this? Why are you carrying a weapon? What are you?" Both knees were on Dean's back as well by now and he was having trouble breathing again.

"I'm human! And a Hunter. I carry it for protection: for myself as well as others. If I'd wanted to use you on you, I would already have done so! I just….I'm just trying to work out what's going on here, that's all! One of us is in the wrong world!"

He fell silent, wincing as he was sure he could feel at least one of the ribs in his back cracking under the bony weight of his brother. Well, the being that looked so incredibly like his brother. Then: "Give me both your hands!"

"What?"

"Your hands! Both of them, behind you! Now!"

Dean swore to himself, but he knew he had no choice. It was either submit to being tied up or risk being crushed beneath this Sammy lookalike who was making it perfectly clear that he didn't care what happened to him. He put his hands behind him and felt his wrists be tied together with some sort of cloth.

Then, just as before, he was pulled to his feet by the method of a very strong hand gripping the back of his neck. Turning round, he noticed that Sam's tie was now missing from his smart suit ensemble, and he knew what was restraining his hands. He also noticed Sam pocketing his gun. "I'll keep this, for safety. You can have it when I get my mate back!"

"I've already told you: I'm as much in the dark about what's happened as you are!"

"We'll see."

This time, Dean made no argument at all as they retraced his previous steps and returned up the stairs. But at the top, once back in the large expanse of empty warehouse, he came to a sudden and somewhat panicked stop.

"What now?" The growl was right in his ear, but Sam broke it off as Dean turned to him with a dazed expression.

"There's no dust."

"What?" But this was said quieter, less anger in the voice. Sam could tell the smaller man was stunned by what he was, or in this case, wasn't seeing.

"The dust. We were kicking it up as we walked through. There's no dust!"

And it was true: the building, although architecturally the same was clean and clear of any debris. And the light was different: the windows were still boarded up, but now the light coming through them was bright from the full strength of around midday. Dean could see the interior of the warehouse quite clearly now: no rubbish strewn around; no crates; no rotting trash can; no thick residue of dust.

"Oh God, it's me that's not in Kansas anymore!"

"What are you talking about? You're still in Kansas City."

"Yeah, but…I don't think it's mine…"

Dean didn't know what to do. Or say. And suddenly he didn't want to go out of that door, didn't want to see what lay beyond. But Sam was making him move again, forcing him to walk to the metal door that he himself had secured behind him when he had come in, and which now was waiting for them half open. And then they were outside, in the bright light of early afternoon in Kansas City in Spring.

But it wasn't the same city as it had been when he had entered the building earlier.

Dean found himself wandering to the entrance of the alley, aware of Sam just behind him with a grip still on his tied arms in warning, but allowing him to see where they were. And it was different: there were the same buildings, the same automobiles. But this was a clean, brightly painted city. There was no grime, no litter, no graffiti.

And the people were different: Dean wasn't sure how, but they were. And then he remembered how this Sam had scented him, and he watched the throngs as they passed him and realised that they were all doing the same thing. No, not all. He could the noses of about half of the people walking past him continually sniffing the air as they walked. It was another sense, as normal to them as breathing or seeing.

And then, as he paused at the entrance to the alleyway and stared at them, a few that were scenting the air as they walked were slowing their steps, and pausing, and inhaling again, and some were turning to scent the air again, and they were staring at him then coming closer. Not just one person...being... but a few of them. Despite himself, Dean found he was taking a step backwards into the solid body of his brother at which point he could retreat no further. Then the passers-by were pressing against him, scenting him, their noses to his neck just as this Sam had done.

"He has a scent, but very faint…But wow!" "Oh by Our Lady, that's so..." "He's beautiful... those eyes..." "Is he claimed? There's no sign of a mark, how much do you want for him?" "That scent. I could take him all day...it's only light but incredibly arousing!" "He's stunning! Name your price. I want him, just name it!"

"What the?"

"He's not for sale. Even though he does tend to open his mouth when he would be better being silent." Sam's voice was stern from behind him, and he was stepping around Dean to put his large body between his brother and his flock of new admirers.

"Sure he's yours? Show me his mark or I'll claim him right here. I can't see his mark!" One bald-headed man was getting belligerent. Dean wanted to tell him to go to hell, but given that he had five beings now crowded around him, reaching for him, decided it would be more sensible to heed the not so discrete warning that Sam had just given him. He might be used to being tied up, but being offered for sale was a new experience that he wasn't so keen on repeating.

"Can't you?" And Sam now had a painfully tight grip around Dean's arm and was pushing him through the crowd, growling at them all as he went in a very unhuman manner until they parted finally but reluctantly to let the angry and extremely large Alpha pass, and making him walk quickly down the street.

"Keep quiet and just keep walking," he whispered in his brother's ear. "We're nearly there."

"Where?" Dean hissed back.

"Here." And Sam was pulling him to a stop beside a modern but boring looking black car, unlocking it with a click of the key he now had in his hand, and pushing Dean in and through to the passenger seat as he hurriedly got in after him.

Immediately he pressed down the doorlocks and sealed them both in. "Shit." He ran his hands through his long hair. "I'd forgotten why Dean hates this place so much. Offering to buy you indeed: like you're a fucking animal!"

Dean watched him as he moved to start the engine. "Is….is that normal? Do you have slaves here?"

"Worse." Sam informed him. "We have a shortage of omegas."