A brief perimeter check reveals to them that, thank goodness, there is only one way in and out of the bar. Working very quickly, desperate to finish before anybody tries to enter or exit, they lay a devil's trap outside the door.
Sam doesn't know if it'll even work. That's how Dean escaped. He said stepping over the markings had "smarted," so Sam's hope is that it will at least catch him by surprise and slow him down, but optimistically, that Dean is in a different body now means it will be completely effective.
He told Cas about the limited immunity Dean displayed back when he first asked what had happened—really, it was just about the only detail he did give him—but neither of them has acknowledged this inconvenience aloud since. All Sam says after they finish up the markings is, "I hope this works."
Cas needs to go in, because he can tell who Dean is. At least assuming there's only one demon in the joint. They briefly debated on whether Sam should come with him or not; Dean would recognize either one of them, of course, and Sam didn't like the idea of sending Cas in alone one bit, but if he makes it out of the building there will be nobody outside to stop him. They don't exactly have time to rig traps at the entrance.
Sam is pretty sure they're in silent agreement that they may need to make a scene. Of course, they would prefer to make a scene outside where there are far fewer people, and he's pretty sure Dean would too. So they have that going for them.
In the end, they did decide to go in together. The plan they formed was flimsy, and as they step through the door Sam is more than a little uncomfortable with the uncertainty of it all, but this is the best they can do.
Cas enters first, Sam making an effort to hide behind him, and glances around quickly. Fortunately, or maybe not so much, it's pretty quiet—it's Tuesday, about to become Wednesday, so there isn't anybody getting sloppy drunk, though there's a reasonable number of people here just being responsible. Except one man: a long-limbed guy, pale as death with gray-blue eyes, having a burger and a beer at the bar area and apparently laughing at his own joke with two pretty women who look a little interested but mildly uncomfortable.
Sam is not at all surprised when Cas turns his head just enough to see him, mutters, "That's him," and then turns back to obviously face Mr. Comedian.
Following their weak excuse for a plan, Sam immediately ducks into the empty booth directly inside the door, tucked into the corner of the small bar. He won't be too visible here.
Cas is going to be the one to approach Dean. Sam already knows that his brother hates him, and he honestly thinks that if he tried just walking up to him now he wouldn't care that he's in a public place; he'd break his beer bottle over Sam's head and cut his body to ribbons. Sam could usually beat him in a fight before (okay, maybe not as often as he'd like to admit), but now, when he's one arm down and Dean has the Mark of Cain? He doesn't like the odds. But Cas—Dean's feelings towards Cas are still up in the air. With him, there's a chance, albeit a small one. And if he can just get close enough to Dean to knock him out, or drive him close enough to Sam that he can do likewise, they might be able to slap on some demon cuffs, load him up in the car, and get him back to the bunker.
During their drive here, after a certain long period of silence, Cas said, "Now that he's in a different body, we need to start considering exorcism."
Sam didn't say a word and gave no indication that he'd heard.
"We don't know exactly how it works and what will happen to him, but if it comes to it, there are worse plans. He'll end up in hell, under Crowley's thumb, and Crowley will very likely send him to us—"
"I don't wanna risk that, Cas," Sam said softly. "You're right, and I've thought about this, but… we can't forget that Crowley is not to be trusted. I'd be surprised, honestly, if he actually sent Dean back to us instead of just killing him. I mean, we've never known him to reliably take the most efficient and logical option, but in this case… we can't barter with Dean's life. I won't let him die."
"Dean can't die. He has the Mark."
Sam sighed. "Thought about that too. It's just… there always seems to be some new spell or ritual or creature that's an exception to every rule we think we know. And… and Crowley knows about the demon-curing ritual. Knows that we keep failing to contain Dean long enough to carry it out. So he might do it himself, and what then? Keep Dean locked up in hell forever?" He fell silent, unwilling to go any further describing that potential future.
Cas said nothing, obviously turning the words over in his head, not trying to argue with any of them, but he looked distinctly unhappy.
Sam knows that an exorcism would be so much easier. They could slip inside, staying hidden, and be halfway through the incantation before Dean even realizes something's wrong. But the chances of killing his brother, of actually destroying his soul or sending it God only knows where, especially when it's in this state, makes him feel sick. He's already established to himself that he will do anything but kill Dean. He hates himself for it, but he can't change it any more than he can command the sun to rise or set.
So they'll just use this sloppy, idiotic plan of trying to get close enough to knock him out. If need be, there's been a cooler full of pouches of purified blood in the trunk of the Impala for three weeks now, so they can get started on the ritual while still on the road.
He realizes he's honestly not expecting them to get that far, to the point that he has no plan whatsoever on how they'll put him in his own body once they arrive. Better not think about it. Focus on the here and now.
Sam watches as Cas draws near, and he sees the moment the strange man at the bar notices. He sobers up immediately, laughter dying and smile dropping off his face. Immediately his gaze sweeps over the area, and Sam ducks his head down, pulling up a menu to block his face.
He feels the man's gaze linger on him, and he tries to breathe as calmly as he can.
Cas's voice is slightly muffled by distance and the muted din of the bar, but he hears it clearly enough: "By all logic, I know that you must be Dean Winchester. But I see nothing of Dean Winchester before me."
Sam peeks out above the menu, heart pounding, trying not to think about how true that is. A wild notion flares up in his mind, that this is all a trick, a clever ruse they've fallen for, and Dean is alive elsewhere, scared out of his wits but with his soul intact.
He doesn't completely banish this idea, because in some sense, it could be true. It's just that "elsewhere" is somewhere inside Dean.
The man seems to think for a moment, and then decide the comment isn't worth acknowledging. By way of answer, he says, "Sam with you?"
Sam freezes, because the other option is to bury his face in his hands and start hyperventilating and maybe even weeping. The verbal confirmation that they've found his brother in this stranger shouldn't change anything. They already knew pretty much for a fact that this is the man they're looking for. And yet here he is, trying to hold himself together.
Cas hesitates before answering, and Sam vaguely wonders how he'll elect to respond; forthrightness in general doesn't seem wise right now, but lying would be utterly futile.
What he does say catches Sam very much by surprise: "I didn't want to bring him."
The man who is probably Dean but just can't be raises his eyebrows. "Oh?"
"He wishes to cure you. I told him that your soul is condemned, marked by Lucifer himself, and that we should not strive to liberate those who are anathema."
He probably pretty much means that, observes a sardonic voice in the back of Sam's mind, and he screws his eyes shut. Realizing that he can't miss a single moment of this, he opens them again immediately.
The man's not playing around. He nods slowly, thoughtfully, for a long stretch of about two seconds, and inclines his head as he asks his next question in a way that is so Dean it's unmistakable, even seeing it on a total stranger. "How'd you two find me?"
Cas barely pauses. "Do you really think I'm going to answer that?"
Voice carelessly even and face totally impassive, the man says without missing a beat, "You might be a bit more chatty after I peel the first few square inches of your skin off."
Look, observes some part of Sam's brain that he can't quite identify, he's talking to the angel the same way you talk to demons.
The exchange has caught the attention of a few nearby patrons, who are glancing over their shoulders at the two men standing in the middle of the restaurant with looks of concern. Suddenly it occurs to Sam that it may be prudent to get as many people out of here as possible.
As soon as the thought crosses his mind he knows he has to try it, even if there's the chance that Dean won't let him. The blood of the people Dean has killed so far is on his hands. He can't let anybody else die. Not if there's something he can do about it.
He sucks in a deep breath, reaches into his pocket, and all at once springs to his feet, displaying his most recent fake badge as prominently as he can and barking to the entire establishment, "FBI. I'm gonna need everybody to vacate the premises, now."
Every pair of eyes in the building, at least two dozen, is on him. Most startled and confused, one very grave, and one quietly amused.
"I said now!" he repeats, voice rising to a full-on shout, and most of them at least begin to stand up, but too many are still sitting there blinking stupidly. Sam sighs a little sigh, reaches into his coat, and withdraws his gun, pointing it straight at the stranger's forehead and cocking it.
The firearm sure gets the job done; the mass exodus that ensues sees many people neglecting to grab various belongings such as coats and purses, and the odd shout of alarm and frantic call to some other patron sounds as they all thread around the three strange men, parting clumsily around them but not daring to touch them, and bolt for the door. Even as they move Sam does not take his eyes off the man, who likewise does not take his eyes off him.
Where Dean's hair is very dark blond and always neatly combed Ivy league style, this man bears a slightly grown-out buzz cut that's a very average shade of brown. Where Dean's eyes are green, these are steely blue. The skin folds around them differently, suggesting somebody who laughs much more readily. He is very tall, even more so than Sam, and something in those eyes implies he is very much enjoying looking down on him.
Sam sees nothing that he knows in the man, but the man regards him with a familiarity that's unmistakable.
The only door finally slams shut, leaving the three of them alone.