Sam unlocked the door to the bunker with a sense of relief. He had wanted to stay in Kansas City until he could work out what had happened to his brother, but this new Dean was so nervous and afraid of everything that eventually he had elected to drive the four or so hours back to where they now lived. At least his brother might feel safer there.

Besides, he reasoned to himself, the odds were good that one of the Men of Letters books would have the answer to what had happened and how to put it right.

So he opened the heavy steel door and turned to Dean. Only to realise that his brother, or the thing that looked so like him, wasn't behind him. With a sigh Sam realised that he was still in the back of the Impala where he had finally curled into the corner like a frightened child and gone to sleep.

Sam took a breath and tried to calm himself before crossing to the car to open the door. "Come on, let's get you inside: you can settle in a proper bed if you want. It's okay, you'll be safe here. Once the door to the outside is shut, nothing can get in." He held out his hand and tried to look reassuring.

Wide green eyes sleepily looked up at him, then Dean was scrambling out of the car and taking his hand. But he still looked nervous as he peered in through the open entrance.

"Come on." And Sam locked the Impala up and led him in. Dean jumped as the outer door shut with its metallic clang and looked as if he would hyperventilate. But Sam was already squeezing his fingers and encouraging him to go down the stairs to the main floor. "There's only you and me here. And we've already established that I'm not going to hurt you…."

This had indeed been established by a long and emotional few minutes in the alley by the warehouse that morning, when Sam had knelt on the ground and held Dean until he had just about cried himself out, trying to ignore the stares of curious passersby. Luckily nobody had felt enough interest to actually come in to the alleyway and ask them if they were alright. Then once Dean had calmed down, Sam had taken him the short distance further into the alley to where they were parked, grateful that he had been the one to have had the keys.

Dean had taken one look at the car and burst into tears again. "What is it?" By now, Sam was getting exasperated.

"This was dad's Impala!" Dean told him through his sobs. "The exact one!"

"So why are you crying about it? Did he sell it?"

"No, he died in it. It was a terrible crash. I miss him."

And Sam had put his arms around him again. Because he missed his father as well: something he never thought he would do until it was too late.

Finally he had coaxed Dean to get into the back of the car: "Just settle down there and get some rest. I don't know about you but I need something to eat. And then we'll try and work out what's happened."

His brother had obeyed and lain down on the rear seat, tense and hugging his arms around himself nervously. But he didn't stay there long: for as soon as Sam had started the engine and eased the car out into the heavy morning rush-hour traffic and the, to Dean, strange new world was suddenly all around them, he was sitting up abruptly and lunging across to the door. Sam panicked for a moment, thinking that Dean was going to run away from him again, but instead he was slamming his hand down on the locks and then huddling, almost cowering against the back of the driver's seat.

"Can they get in?" And Sam realised that he was talking about the herds of pedestrians that were surrounding the sides of the car.

"No. Not now we're locked in."

He was startled as he felt something on the side of his body: Dean's hand was creeping around the edge of the seat, desirous of physical touch to soothe his obvious fear of the throngs of people outside. More than physical: Sam felt himself becoming alarmed as well as slightly….aroused… as his brother's fingers slipped beneath the hem of his undershirt until they were resting against his warm skin.

Somehow Dean's touch was incredible. And there was something else distracting Sam from having full attention on the road and the heavy traffic in front of them. He wasn't sure what it was until Dean shifted his position slightly to push his full hand around Sam's now exposed waist and then he realised.

It was the scent in the car. One that he had never smelt before, and yet he had, but nowhere near as strong as this. An aroma of sweetness, of spring; of meadow wildflowers; of the muskiness of the leather in the Impala: no, it was a muskiness that was Dean. Somehow he associated this scent with Dean.

He inhaled deeply and realised that it was emanating from his brother… from the being that looked so much like him. But in the confined condition of the car, it was really strong, seeping into every one of Sam's pores. And it was causing far more of a totally incorrect response in his body than a simple family member's touch and smell should do.

"Dean?"

"Yes, Sam?" The other had his head leant against the back of the seat and his eyes closed tight against the terrifying world outside their enclosed travelling box.

"Hands off, dude."

The other pulled his hand back as if he had been scalded, then huddled back onto the rear seat, trying not to look out of the window of either side. "Sorry."

"It's okay."

But it wasn't.

Because Sam was really disappointed and wanted his brother's touch back on him again. He found himself wishing he hadn't said anything, and then he wondered why he felt like that.

He had noticed a drive-through when they had arrived the previous day and headed towards it: he hadn't eaten since the previous evening and he was guessing that this being, that was so like his brother in looks, would share the same large appetite for food. "What would you like? Bacon cheeseburger with fries?"

To his surprise, Dean had looked at him with disgust through the rear view mirror: "Blegh. Salad is fine."

"Fried chicken with it?"

"No. Nothing fried."

So Sam had gone to get himself breakfast and the other some food and decided there and then to drive all the way back to the bunker, as Dean had freaked out when he had opened the window at the serving hatch. Staying in a public motel with him would not be a sensible idea.

They ate as he drove: Sam worrying for once about how little his brother seemed to be eating. But Dean seemed perfectly satisfied with his order plus a bottle of water, while Sam picked first at his own burger and fries that he told himself he had only bought for convenience, then he ate a second portion of both that he had got expecting the other to change his mind and want anyway.

And they had talked.

Sam asked him to remember in as much detail as possible what had happened that day, which turned out to be very similar to his and his brother's experience: he and Sam had been in the cellar, this Dean had seen the pale blue glowing thing, his Sam hadn't. Dean had moved to touch it, there was a blinding flash of blue light, and then he had woken up in the cellar, and the rest Sam knew.

"So what do you think it was? Could you feel something physical when you touched whatever it was? Or just an energy?"

"Definitely something physical. But it was glowing then: now it just looks like a stone."

"So….enchantment perhaps? A spell of some sort?" Sam was trying to think, then he paused: "What did you just say?"

Dean fumbled in his pocket and pulled something out. "I said: it just looks like a stone. But this is only half of what it was. Your Dean must have the other half."

"I….what?" And Sam was pulling over to the kerb, and reaching round to see what Dean was holding out to him.

It looked like a stone.

Just a stone.

A plain stone-coloured stone, small enough to comfortably fit in his hand. Or it could have been a large pebble: a near-perfectly smooth flattish stone that would have been perfect for 'skipping' across water had it been in one piece.

But one edge was straightish, and jagged as if it had been sheared away from a corresponding piece. And somehow the edges of the broken-off part of it looked glassy as if they had almost been molten by some tremendous heat or force.

"I tend to hold tight to things when I'm anxious," Dean commented, "but the thing glowing was larger, twice the size of this."

"So, you think whatever this is, it broke? When whatever happened, happened?"

"You're not very articulate, are you, Sam?"

Sam glared at him and started the car up again. "Keep that safe. I'll examine it properly when we get to the bunker."

"Do you think your Dean went to where I come from?"

"I'm hoping so. It would make sense that you've swapped places: we 've just got to work out how and then swap you both back safely."

But Dean didn't respond. And Sam later wondered about that.

First and most important thing though: get the 'new' Dean into the bunker, get him settled, then attack the books. "You can have Dean's room….erm, my Dean's room, or choose one of your own. It's that way….."

But his words tailed off as Dean straightened up where he stood, and inhaled deeply. "Yours is there." He let his nose follow the scent and his feet took him directly to, and straight into, Sam's room, with the young man trailing after him in amazement. "Mine, well, the Dean of this world: his is here." Again he was correct. "May I?"

Sam nodded as he indicated the door and opened it.

He didn't seem very impressed with Dean's bedroom, his eyebrows went up at the sight of the weaponry all over the walls, but he stood and looked around. Sam noticed that he still seemed to be inhaling as he did, but he made no comment. Instead he turned expectantly to Sam: "I am to stay here?"

"If you want. Just… look, please be careful of my Dean's stuff. He hasn't got much and he gets possessive over it, but at least I know his clothes will fit you. You can borrow any of those you need.

The bathroom is down the hall. We have a kitchen you can use, and you're welcome to explore, but...well... I meant what I told you about this place on route. Just don't go touching anything in any of the other rooms without checking with me: we've got enough weird to deal with at the moment without anything else getting chucked into the mix. But it's safe here. You'll be safe here.

I'm going to start trying to try and work out what's happened. So...shout if you need anything, okay?"

ooooooooooxooooooooooooo

Sam pulled the car up to the small house where he and Dean lived. He was proud of it: it wasn't huge and had only one upstairs bathroom and a small downstairs restroom, but it was in a good neighbourhood in one of the outer suburbs of the city that was filled with families like they were: hard-working, respectable and a good mixture of Alphas, omegas and betas. They all looked after each other and he was satisfied that his beautiful mate was safe there.

He turned the engine off and looked over at the strange but identical being who had somehow taken the place of his Dean. "Look," he began hesitantly. "I don't know what's going on, I can't even get my head around what happened, but you've seen how unsafe this world will be for you. I'm…just asking you to behave when we go in. The kids are going to be upset enough at the disappearance of their mother, all I'm asking is that…"

"Wait! What?" And Dean was sitting up straight in the passenger seat, his eyes wide. "What do you mean, mother? You mean, Dean? The other Dean: he's a mother? How….how?"

"Well you see, there's these birds and some bees…"

"I know how, bitch! Actually….no! I don't know how! He's a man, right? The other Dean? He's male, like me?"

"He's a male omega. Like you. Jerk."

They each looked at each other as if a challenge had been set: somehow they had both passed the test and the first connection had been made.

"What the hell is an omega? And how the hell does a man have a baby?"

"It's what Dean is, and it's normal here. You can't have children? Even though you have the scent of an omega, faint though it is, you are more of a male beta?"

Dean snorted. "What the hell is a beta? And no man where I come from can. Only the women."

Sam stared at him in wonder. "Here the female betas can, and both sexes of omegas. But all omegas are getting rare now, and male ones like my Dean especially so. With so many betas breeding with each other, well, even Alphas are beginning to be bred out. The population is changing quite markedly, and earlier you witnessed the result."

He sighed and leant forward confidentially, "To be with an omega, Dean, is….quite incredible. Every Alpha wants one, and unfortunately that means it is getting more and more unsafe for them to be out unprotected." He scrubbed at his face: this was getting off topic. "You're…he….my Dean. He's my mate, and the love of my life. And the mother of our three children. I just want to know he's safe."

"Three!"

"Two sons and a daughter. And they all are going to be distraught about their mother's disappearance. Just…please…"

He glanced over at the man sitting beside him in the car. A man who had his hands still fastened together behind him by Sam's tie. A man who had appeared from nowhere in a cellar at exactly the same time that his mate had vanished. He didn't know what he was expecting when he glanced over: anger; hatred; fear?

But all he got was a nod. "In my world, Sam and I are brothers. So you're mates? And you've got kids, huh? How old?"

Sam felt that a huge pressure had just been lifted off him. "Come and meet them." He got out from behind the wheel and went round the car to help the other man out, leaning over him to undo his seatbelt, and pulling his body forward slightly so he could undo the tie from around his wrists.

Instinctively he scented the smaller body as he did: the aroma of his mate was there, but faint, much fainter than normal. He really had to inhale deeply to drink it in, but it was the same. Just as sweet, just as intoxicating.

Just as arousing.

Somehow this man was exactly the same as his mate but from another world, another dimension. And Sam's organised, lawyer mind couldn't compute that at all.

The tie had cut into Dean's wrists enough to make marks, and as he got out of the car he rubbed absently at them to try and restore the circulation. Then to his shock, Sam was catching at them in his large hands and kissing tenderly at the sores. "What the….?"

He snatched his hands away and glared up at his brother, who looked down at him in a slightly dazed fashion. Then they were both startled by a shout from the neighbour who had witnessed it. "Hah! Sam! In trouble with the Missus? Not like you!"

Sam recovered himself enough to laugh loudly and call back: "I'm always in trouble, Ronnie! But it's worth it just to get the make-up sex!"

Ronnie paused and looked at them: no, he looked straight at Dean. "I'd be in trouble all the time if I had that in my bed, Sam." It suddenly wasn't just banter: his tone was leering, his eyes undressing Dean where he stood, his tongue absently emerging to lick at his own lips.

Despite himself, Dean shuddered. And he smelt, he actually smelt the rage that poured off Sam at the crude words. His brother had a definite aroma around him that suddenly increased exponentially. He realised that he had smelt it before, in the street with all the onlookers scenting him, but he had been too stunned by what was happening to have taken much notice. But there was no escaping it here, especially as Sam was protectively pulling him to stand behind him.

"What's that supposed to mean, Ron?" The words were snarled.

The lusty smile wiped quickly off the neighbour's face. "Nothing… nothing, Sam! I'm just saying….Your Dean is a mighty fine looking omega. You're very lucky!" And he was hastily backing away and up the driveway into his own house.

The two brothers stood in silence for a long moment. Dean could see the tension in Sam's shoulders and after being manhandled around by him earlier, he really didn't want to disturb him. But… he was tired, he was hungry, and he desperately needed the bathroom. So….

"Sam?" And carefully, he put his hands up onto his brother's shoulders and began to massage them, hoping he wouldn't just end up flat on his back on the ground again. "Shall we go in?"

Sam stirred: he stretched out his back and straightened up to his full six foot four height, feeling his muscles yield and relax beneath the touch of his mate. Well, not his mate, but at least they could give the impression to that fucking leering bastard next door: if he ever looked at Dean like that again….

His mate had been telling him the truth: not even here was safe.

He turned suddenly and grabbed for the smaller man, pulling him close and plunging his tongue into his mouth.

"Nrngh!"

But Sam had his arms tight around him and wasn't going to let Dean go no matter how much he tried to break the hold. "Make it look real! I mean it!"

He could feel the revulsion in the smaller body pressed against his, but Dean fought it down and tried to act as if he was enjoying being kissed by his younger brother.

To his chagrin, Sam realised that he didn't have to act. His eyes were dark with lust when he finally released the other man from the enforced embrace, and Dean was alarmed when he realised how hard his brother was in his suit when he stepped back. Sam could see the nervousness in his face, but then he was taking Dean's hand and leading him into the house. "I'm not going to touch you, just play along." Just for good measure, he put his hand on Dean's ass as he allowed him to go in through the door first: that will show that bastard Ronnie!

Then, as he had expected, Dean was pulling away from him the moment they got inside out of sight.

"What the fuck was that about?"

Instead of an answer he found himself being slammed face first into the nearest wall. "I have told you, our children are here! If I ever hear you use language like that again, I will…"

"Dad?"

As one they turned, and Sam hastily released his mate….thing that looked like him, instead keeping his large hand around the back of his neck as a warning as well as a tight grip on his arm. But Dean was staring at the children.

He could see himself in them: they all had his eyes, his long eyelashes, his full pink lips. And they all had Sam's long limbs, and he just knew that they had his dimples. Two younger ones: a boy of about nine and a girl of about seven. But it was the eldest one he couldn't take his eyes off: "He must be, what? Sixteen? Seventeen? How old was I when I had them?"

And the boy….young man was stepping forward with just as much interest. "This isn't mom. But he's…." and his nose was suddenly against Dean's neck, breathing him in. "His scent... it's beautiful."

"Whoa. Whoa!" Dean was pulling away seriously unnerved by his proximity, and hurried to hide behind his brother…thing that looked like his brother. "What the hell is this place! What's with all this...touching and sniffing me!"

"Samuel, behave yourself!" Sam sighed. "No, he's not your mother. But you will treat him with respect, please. He's not… like us, in fact he seems to be very different. I mean it, Samuel."

The young man pouted: an action very reminiscent of his father, Dean thought, but he obediently stepped away. Although his eyes never left Dean's face.

"Dean. This is Samuel, he is sixteen: you were nineteen when you had him. And this is Johnny, and my little Mary-Anne. Children, something very strange happened today, I'm not sure what, and I can't explain it. But this is Dean. As you can see: he is the image of your mother. But he is very different: his lack of scent for a start. And for that reason, it will be best if we don't mention that he isn't your mother outside this house. To anyone. It could make it very dangerous for him here if we do."

The last sentence only nearly caught Dean's attention away from what he was trying to work out: "If I was nineteen, then you were…"

"Fourteen, Dean." Sam sighed. "I was fourteen when we first mated. I know you don't understand."

"Fourteen? You were fourteen? I… was it me? Did I corrupt you? Oh God, what did I do? How could I have touched you: you were just a kid yourself!"

Sam turned and stared at him. Dean didn't understand his expression at all. He understood it even less when Sam suddenly smiled genuinely at him, his dimples dipping to their full depth, yet with an intense sadness in his eyes.

But he didn't answer the question.