Okay! Here's an AU tag to 3.15 Time Is On My Side. Rating is for a bit of language and some goriness. I just had to write this after seeing the ep--I spent the entire time thinking about it. Thanks for reading!

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Mercury, Salt, and Sulfur

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There's no black magic, he'd said. It hadn't been exactly true. It's mostly science (yeah, weird science), and most of it makes some sort of really strange sense. But alchemy, well…it isn't quite safe. There's a reason most alchemists are fucked in the head. Hell and alchemy go hand in hand, see.

It's just a different sort of hell.

--

9:38 and Dean won't shut up. About three hours ago he realized that this is it, and he's been getting hoarser and hoarser as he spills secrets and thoughts and stories about mom that he thinks Sam should know. His eyes keep flicking between the dim red lights of the motel room's alarm clock and Sam's hollow face, and his hands are clenching the denim of his jeans into sweaty bunches.

At 9:52 Sam stands and walks over to his duffle bag. Putting his back to Dean, he grabs an old t-shirt and the bottle he nicked from Benton out and douses the cloth. It's rudimentary, but it'll do for now.

Dean keeps talking the whole while, as though he knows that if he stops he won't be able to start again. He pauses only when Sam moves to stand in front of him. His mouth hangs open slightly as he tips his head up to look up at his brother.

Sam's face crumples, and he says only Dean in a lost voice before shoving him back hard onto the bed and pressing the chloroform-soaked cotton over his mouth and nose.

Moments later he's carrying Dean in a fireman's hold out of their room and to one a few numbers down. When he kicks open the door, he sees the twin beds have already been stripped: one is empty, and one has a prone body strapped to it.

Benton's patchwork face smiles stiffly at him as he lowers Dean onto the unoccupied bed. Sam turns, expression like stone, and says bluntly, "Show me how."

At one point the unknown man on the second mattress starts groaning, then screaming as Benton skillfully slices off a piece of skin. Sam doesn't want to know (can't know, jesus christ, he can't know) so he dumps more chloroform than he needs onto the t-shirt he's still clutching and tries hard not to feel anything when he crushes it against the man's face.

Then it's 11:59 and Sam's holding a gun to Benton's head as his breath comes in short hitches. (He figures it'll slow the good doctor down if nothing else.) He can't hear anything at all and it's making him panic. But even if he can't hear the hounds' presence, he sure as hell sees it when the dull pink of Dean's flesh suddenly gives way to the wet red underneath in four long claw marks.

Dean's still out, but even so his face contorts in agony. Sam clicks back the hammer and Benton hisses, "Have a little patience."

And as he watches the hounds flay Dean, he sees that for every gash there's a sickening oozing of regrowth as skin sucks back to the piece it was torn from.

(The body can't live without the soul, Benton had said when Sam snuck back and dug him up. And if the body can't die, then the soul by rule must stay.)

Dean's arching off the bed, eyes open now, bleating in pain as he's shredded again and again. But he's alive, he's not dying, and Sam's mind reengages as he scrabbles for the Latin charm he's got scrawled on a sheet of notebook paper. His voice is breaking and it's hard to concentrate with Dean shrieking like that, but he gets through it and the room seems to shake as the angry red wounds stop tattooing Dean's skin.

Benton nods and moves into the space between the two beds, prodding at Dean and muttering that he'll need a new epidermis for the torso and right calf and it looks like the stomach has been punctured badly enough to warrant replacement, but everything else seems to be in decent order.

Dean is panting, the ribbons of what used to be his chest melting into each other as they try to sew themselves into some semblance of skin. His eyes are drilling into Sam, the pain-brightness of them offset by the garish smear of blood left by an already-closed cut on his eyebrow.

Sam flinches as he spits, "What the fuck did you do?"

--

They spend two days in their motel room, the stench of necrotizing flesh and antiseptic hanging close around them. Dean is rotting, the grafted skin greying and flaking. Benton swears this is normal, that his body will adjust with a little time.

(He'd pointed to the stitches running across his own skin like spider tracks, saying, These are only from desperate measures—he's still got most of his skin, he won't have marks like these just yet.)

On the third day Dean starts scratching at his skin. He hasn't been speaking to Sam, just lying silent and stinking on his bed, occasionally slapping at the flies that made it past Sam's watch. But now he scratches, blunt nails picking and tearing. Sam glances over, but has to turn away when Dean starts to slough off entire chunks of skin, only to have them replaced with a raw pink underneath.

And then Dean stands, parts of him looking normal and parts of him wet and shiny like he's had a bad sunburn. Pieces of grey flesh fall onto the speckled orange of the carpet as he flexes the muscles of his arms and shoulders. It's like some sort of perverse resurrection, and Sam feels vaguely ashamed.

--

They aren't welcome in South Dakota anymore. They'd showed up at Singer Auto Salvage two weeks after the incident and Bobby'd been shocked then horrified to see them together. And Dean, Dean just didn't listen when Bobby told him to get the hell off his property, which led to Dean getting his leg shot off at the knee. Which, of course, led to Sam breaking Bobby's nose.

Dean's shuddering from blood loss when Sam drags in the hiker he'd found on the side of the road. It's just like patching up any wound: clean cuts and careful stitching. Eighteen hours later, Dean's got a new left leg and the hiker is in intensive care at Avera Sacred Heart.

(It will get easier, Benton had said. For both of you.)

Benton had been right—Dean's right as rain in practically no time.

--

Dean doesn't go out anymore. He still hustles pool when their cash is low, and he still eats in diners, but he doesn't go to bars to drink and he doesn't try to pick up girls. Half of his body is covered with the faint discoloration indicative of healed second-degree burns, and after his last one-night-stand asked what'd happened, he gave all that up.

Sometimes Sam begs him to go out, to see somebody. "Just keep the lights off, tell her it's none of her business," he says. Dean turns a carefully blank face towards him and doesn't respond, and Sam can't help the surge of anger he feels. Dean would've been in hell without this, and he thinks he's suffering?

But finally Sam stops asking and Dean just sticks close to whatever motel they happen to be staying at that night.

--

It's easier to hunt when you don't have to worry about lasting damage.

The ear ripped away by a wendigo is replaced with one from a ritualistic murderer.

The fingers blown off in a shotgun blast are replaced by those of an abusive father.

The damaged liver is replaced with a healthy one from a snoopy cop.

The collapsed lung with the spike driven through it is replaced by one from a convenient kindergarten teacher.

--

One day, long after the whole affair with Lilith is put to rest, Jo dies. She's caught off-guard by a werewolf she'd been trailing and gets her heart ripped out.

The Winchesters are pariahs by this point—no hunter will associate with them for love or money—but they still hear the rumblings of Harvelle's little girl found with her chest cavity split open and her innards devoured.

Somehow they make their way to Nebraska to where the Roadhouse once stood. There's a pyre set up amidst the low scrub, and in the moment before Ellen sets it ablaze, Sam wonders at how old Jo looks. There's a scraggly gathering of hunters there, friends of Jo and friends of her ma, old men who watched her play Barbie under the pool table, do homework at the well-polished bar, and down shots with the big boys.

Ellen turns and sees them through the crowd, and Sam realizes with a shock she can't be younger than sixty-five. Her lips thin even more while her daughter's body burns behind her, and Sam lowers his head.

Dean, an ugly scar curving across his forehead and down the bridge of his nose, simply blinks his month-old blue eyes while he stares off into nothing.

--

The Impala sputters and dies in Minnesota. This isn't the first (or second or third) time this has happened, so they push it to the side of the road and go looking for a mechanic. Problem is, the make is nearing seventy years old at this point, and finding parts is as likely as striking gold. Luckily, Dean went through a phase of buying every '67 Impala he could find and putting them in storage to ransack for parts should something happen to his precious car.

While the car's resting at a shop in Anoka, they catch a bus to St. Paul and hit one of the storage containers Dean rented nearly a decade ago. Digging around under the hood of the seafoam Impala, Dean turns and gives Sam a lopsided grin. "Matched pair, me and my baby, huh?"

It's not funny, not really, considering. But Sam doesn't see Dean smile so often these days, so he laughs like it's the greatest thing he's heard in months and locks that memory away inside.

(It will get easier, but he wonders if that was a lie.)

--

Sam awakens feeling like he's been sick all over himself. His skin crawls and his arm is like lead. This must be death, he thinks. He rolls his eyes to see because his head won't move, and there's nothing but hideous motel wallpaper in three directions and Dean in the fourth.

Dean is pressed against the door, eyes wide (one blue one brown), hugging himself. "I'm sorry," he whispers. "Sorry, god I'm so sorry Sammy. But you were dying, and I couldn't…I can't, Sammy, you understand…not without you…"

And Sam remembers, remembers the unbelievable pain throughout his entire body as his arm is wrenched from his shoulder, the blood, the grey blossoming across his vision. And he forces his head to roll and he sees the dead flesh of an arm that is not his arm (but it is now).

"Oh," he says.

--

There is no future, because the future is just now, you see. The years rolling by endlessly, punctuated by a new heart here, a new pancreas there. It's not so hard. They're used to being nobodies, a different name on a different ID in every state. Eventually everybody who knew them back at the beginning dies off, and they don't go looking for new acquaintances.

One night in Louisiana, Sam's bringing a sack of burgers back to the room when he gets shot through the thigh. He drops the bag and swings around, and there is a man standing across the parking lot whose face is grim but whose knees are locked in terror. He blinks (grey eyes but one of them is developing cataracts—he'll need new ones soon), because it's been so long since he's seen another hunter. They haven't run in that circle for well on a century.

Another shot punches straight through his stomach. The door to room forty-six opens and Dean comes sprinting out. The man draws a bead on Dean but the gunfire doesn't even slow him. Within moments he's slamming the man's head into the roof of a nearby car. Bleeding and half-conscious, the man groans unintelligibly as Sam limps over. His expression is panicked as Sam snatches the gun (Russian make—the last of the American manufacturers went under decades before). His gaze keeps flicking to a nearby automobile, and Sam hobbles over to make sure that the guy doesn't have a partner waiting.

Instead, he finds a small child huddled in the back seat, arms folded tightly over her head. Dean gives a sharp bark of surprise as the guy knees him suddenly, fighting for freedom. Sam watches as Dean slams the man's head a few more times until he slumps. Dean starts to drag him inside (he needs a new shoulder, Sam needs a new stomach and maybe some work on his thigh).

Sam turns away from the girl to follow Dean.

They're not monsters. They're not.

It's just a different sort of hell.