It's the rot that does it. Right from the start, the sheer fact that the patch of wood has been dead for too long is what causes all their problems. And then Sam, half-blind in the darkness without a flashlight, puts his foot down in the wrong spot on the barn roof, and a whole section of wooden planks seems to just crumble right out from under him. He has time to make one fast, frantic grab for the edge of the hole, catches hold, and thinks he's safe for all of a split second before that gives way too.

He falls with a shower of splinters and the explosive sound of shattering wood. The floor is incredibly hard when it rushes up to meet him; his head makes contact with a crack, brain slamming up into the front of his skull, and the world skitters off into blurry darkness.

…

Dean watches Sam go down in the sort of sickening slow motion that only happens when you're watching life break and change forever. The crack and roar reaches his ears a heartbeat after Sam's silhouette twists sideways and vanishes through a hole torn in the barn roof. He hears it as he's scrambling down the wooded hill just a few hundred meters from the building, troll be damned, because there is no way Sam is landing on the bare ground after that fall and walking away unscathed.

The troll can come for Dean if it likes; it's not getting his brother.

He skids down the hill through mud and leaf litter, shotgun in hand, machete on his hip, ears straining for the telltale wheezing breaths or lumbering footsteps of a troll. But he can't hear anything over the blood roaring in his ears, fear – not for himself; for Sam, Sammy; it's not touching him – reining supreme over caution and sense.

The average troll stands seven feet tall at the shoulder, has skin similar in color and thickness to a rhino, and weighs in at something close to two thousand pounds, burdened down by muscle and bones so dense they're almost unbreakable. They run on all fours, but can stand on their (relatively) stubby legs and walk as well, and prefer to live in family units of two to five. Like many other unpleasant creatures, they actually prefer caves to human dwellings, but this is not the first time that the trend has been broken. They're nocturnal, rolling themselves up into enormous, armored boulders during the day that are damn near invincible, and easily blend in with the forested landscape if stumbled upon. The best way to kill them is with a well-placed blade; there are cracks in their natural armor around their joints, and if you can get a machete into the slit at their neck, the thing's done for. The shotgun's main purpose is to slow them down.

This one is a rare case; there appears to be only one troll roaming around here, which is why the Winchesters are handling it on their own instead of bringing in backup. It's been picking off hikers and tourists in the area since last spring; authorities pointed fingers at mountain lions first, then wolves, then bears, and recently began trying to pin the blame on a serial killer, since extensive searches of the area have turned up nothing more than a few smears of blood scattered across almost a hundred acres of forest (trolls eat everything when they kill, including bones).

Sam had dropped onto the roof from a nearby tree and gone clambering along it to see if the troll was inside while Dean scouted the perimeter. They'll know for sure now; if it finds Sam incapacitated, he's dead.

Not if I get there first.

Dean digs his feet into the soft ground and runs faster.

…

The whole world is ringing like he's been trapped inside some massive bell. He sucks in a breath that burns his ribs and spine and tries to remember where he is, who he is, and what he's supposed to be doing. He starts to reach one hand up to touch his forehead.

"Don't move."

He freezes obediently. I know that voice. There's only darkness above him, save for one jagged hole in the rafters that the moon is shining through. Where did… did I fall?Very carefully, he rolls his head to the left. A tall, solidly-built blond man leans against the wall just a few feet away, arms crossed, staring at something across the room. His gaze doesn't shift, but he smiles.

"Gave yourself a bump on the head, you did, Sammy. Might want to watch that. Falling through roofs isn't a good habit to cultivate; you might end up permanently scarring your brain or something. Oh, wait." The blond man slaps one hand against his own face. "That's already happened! Silly Lucy!"

He blinks. Sammy, right. Sam. My name is Sam. Sam Winchester. He starts to move a hand towards his head again.

"Didn't I tell you not to move?" The man – Lucifer, he remembers now. Lucifer, Satan, the Devil, in the Cage, in my head. He keeps talking, so Sam makes himself listen. "There is a troll, like, forty feet away from you, and I cannot tell you how lucky you are that it's the polite sort who doesn't leave the table before it's finished eating." He takes one look at Sam's furrowed brow and continues before he can speak. "It's munching on a hiker. If it sees you move and realizes you aren't dead… you won't be not-dead for very long." And then he smiles. "Aren't you glad you have me, now? I tell you all the little bits you need to know to survive."

Sam blinks again. His skull is throbbing, as is his entire ribcage. Just lie still, his brain commands him. Dean will come get you. Your brother, remember? He'll get you out of here. He always does. Closing his eyes, Sam swallows, holding down a wince.

The ringing is fading, giving way to soft rumbles, the sick sound of ripping flesh, and the heavy, whistling grunts that is the troll breathing. Ever so softly, Lucifer begins to hum in the background.

…

The road is unpaved, and Dean's feet squelch in the mud as he runs. The nearest wall of the barn is only a handful of yards away now; he just has to circle around to the door, then he can grab Sam and get out of here, leaving the troll for another day.

But then there's another sort of squelch – wetter, longer, followed by a crunch that can only be bones getting crushed between massive teeth. Dean stumbles to a halt in the shadow of the barn, free hand pressed to the mossy wood, holding his breath. Skin tears, muscle rips, tendons snap like whips. Another grating rumble rolls through the air.

That had better not be my brother you're eating. Sinking into a crouch, Dean drops the hand off the wall to brush the machete's hilt, but doesn't draw it. He needs both hands for the shotgun if he wants half a chance of holding it on target. That being said, though, he doesn't feel capable of keeping anything steady.

The image is dancing in his mind: Sam, limp as a ragdoll, getting his ribcage torn to shreds by a living boulder, but he's still alive, still breathing, head lolling, searching in vain for his older brother – the one who's supposed to take care of him. But Dean's nowhere to be found.

As long as I'm around, nothing bad's going to happen to you, Sammy. It's a promise he's reminded himself of countless times in the past seven years. It's a promise that he keeps breaking, too.

Teeth sinking into his lip, Dean eases forward one step, then two, then three, slipping around the edge of the door with the liquid ease of spilled water, squinting through the abrupt blackness. The only light is from the moon, filtering down through cracks in the boards of the roof, and one gaping hole to Dean's left. There are shelves and walls that used to divide stalls blocking his view of the ground below the opening, so he can't see if his brother's still there. The troll is feasting somewhere to his right, and the stench of man-eating monster hangs thick in the atmosphere, clogging his throat and making his eyes water. It's still noshing away, ignorant of the intruder.

Kill the troll. Get Sammy.

Dean slinks forward, step by step, letting his eyes adjust to the gloom, bringing the shotgun up to his chest and holding his breath every time he moves. Eventually the looming gray haunches of the troll materialize out of the darkness, little more than an arm's length away. Its back is turned to him, an impenetrable wall of muscle and hide, so he begins to step to the left around it, towards the open space of the barn.

His toe nudges a rusted pitchfork with the smallest of clatters, and he freezes, breathless. The troll either doesn't hear or dismisses the sound as nothing of note. Dean lets his shoulders relax. On his next step, his foot lands in a knee-deep hole in the floor, and he goes down.

…

There's a thud and muffled curse in the darkness, followed by the sliding, teetering groan of unbalanced metal, and then a clamor that resounds off the walls and drills into Sam's aching skull – it sounds like someone just knocked over a shelf of gardening tools. Maybe that's exactly what happened. How or why is irrelevant, though, because the troll leaves off eating to snarl into the darkness.

Sam peels his eyelids open just in time to have Lucifer say "Whoops-adaisy" and disappear. When he twists his head to the right, there's nothing to see besides vague shapes and shadows. Dean, he wants to call. Dean, I'm here; I'm alive. Are you okay? Instead he eases up on his elbows slowly, head swimming from the change in elevation.

The troll – a blurry dark gray mountain surrounded by blackness – sits back on its haunches and roars, then comes back down to all fours to lumber forwards. Not towards Sam, though; it moves further into the dark, towards the noise. Towards Dean.

Heart climbing into his throat, Sam shoves himself into a sitting position – anything's better than lying down like a victim – and makes a move to roll upright. His brain has other ideas. Self-preservation aside, it tugs at the cords in his brain stem, sending him to his knees and pulling up dinner for an encore appearance. For a terrifying moment, the edges of his vision fuzz into creeping darkness and the sound of the troll moving across the room is swallowed by rushing blood.

"Dean," he whispers to the puddle of sick in front of him. Then again, louder: "Dean!"

With a grunt that sounds like rocks grinding, the troll stops moving. When Sam lifts his head, he can make out its storm-gray body shifting in direction, turning towards him, black eyes the size of Sam's fist like six empty holes bored into its massive head. It's relatively small – only a bit more than five feet tall at the shoulder, probably still growing. Below its nostril slits, the whole of its craggy, armored face is black with blood, and he can see flesh clinging to its dagger-blade teeth when its head splits almost in two, as that cavernous mouth opens in a roar that shakes another board loose from the ceiling.

"Get up, Sammy." Lucifer is standing at his side. "Up," urges the Devil, "unless you want to know what a troll's intestinal tract looks like."

"What do you care?" Sam grits out.

"I haven't got much use for a vessel whose body has been turned into troll shit. Get up!"

I can't, says his brain. I can't, can't, can't, can't. But he plants both hands in the dirt as the troll rakes a thick, four-toed paw across the floor, taking down a wall of one of the stalls as easily as a human would flick their wrist. His legs don't want to obey him – the right knee tries to fold back in on itself when he first straightens it out – but, gasping from the bottom of his lungs, vision white with nausea, both hands locked onto the top of a nearby stall door, Sam finds his feet.

Across the barn, a pile of metal and wood shifts, dislodged pieces skittering down off the sides with rattles and thumps.

Still leaning most of his weight on the door, Sam doesn't know if he wants to laugh or cry when the troll shakes its head and pivots again, grumble crawling from its throat. Its footsteps don't actually make the ground tremble, but it certainly feels like it to Sam's water-weak knees.

Lucifer lingers beside him. "Let's get out of here; your… the idiot's lost. We need to go."

Sam slams his hand down onto the door, relishing the way the Devil's image flickers and vanishes as splinters plunge deep into his skin. "Never," he hisses.

…

So Dean's partly buried under what feels like half the building with only his head and shoulders free, there is an angry troll walking towards him, and his ankle may or may not be functional and capable of bearing his weight. But Sammy's okay. Dean heard him, just a minute ago, and the troll is coming after Dean, not his brother.

He can work with that.

He curls his fingers around the trigger of the shotgun, cradling it against his chest, muzzle pointed towards the sound of the troll. The flat of the machete's blade is pressing down against his thigh, too, so he's alright on that front. All he needs is to get off one good shot – maybe take out a couple of the fucker's eyes, but really just incapacitate it enough for him to get close and take one good stab.

There's a noise not unlike a tree coming down as the troll plows through a support beam on its way over to Dean. Its eyes blink, three at a time, twin rows across the top of its head. Pupil, iris, and sclera are all indistinguishable from one another in the black pools. Reaching out a paw roughly the size of Dean's head, it takes the first swipe at the pile of junk, dragging free wood planks and rusted metal shelves with a horrid screech. The movement exposes the junction between its foreleg and shoulder for the briefest of moments.

Shotgun already braced against his chest, Dean sights down the barrel, sucks in a breath, and pulls the trigger.

…

The troll rears back on its hind legs in the aftermath of the shotgun blast. It screams – not a roar, a scream – fit to wake the dead, once as an initial reaction, then again when it drops back down to test the strength of its damaged foreleg. And there's a shape moving almost directly underneath it; something long and vaguely human-shaped, white and gray against black, pulling itself free of the wreckage.

The breath rushes out of Sam as his brother looks around and starts to stagger across the barn towards him; there's even a grin starting to stretch across his face… until he catches the continued movement behind Dean's shoulder.

…

"Sammy," he calls, and his voice does not crack with relief that Sam's apparently only a little worse for wear. "You scared me there, man. Don't do that again."

Sam's holding himself up on an old stall door or something, face pale, and the smile is slipping off his mouth as fast as it appeared. "Dean," he says, urgency clear in his tone. "The troll."

One of the first lessons John Winchester taught his sons was don't back off until you're sure it's dead or totally incapacitated or locked in with no hope of reaching you. It's a lesson that he should have remembered, Dean thinks dully, as the troll's foreleg slams into him with the force of a battering ram and sends him flying.

…

The only thing more terrifying than watching the troll swat Dean away like a fly is watching his brother hit the wall a few feet away with a crack that sounds like it broke half his bones, then crumple into a motionless heap.

It's just Sam and the troll now.

Ducking its head so that those eyes shine wetly in the moonlight coming through the hole, the troll lets out another roar. The leg it flung Dean with is now curled in against its chest, not taking any weight and protecting the hole that the shotgun left. It can't move at full speed with only three good limbs, but it can still bull-rush Sam – which it does.

Another load of adrenaline gets dumped into Sam's system as he watched the mobile mountain charge across the barn floor towards him, but he remains planted where he stands. Not until the eyes flick shut in the last moment before impact does he throw himself out of the way.

The troll crashes into and through the stall door, but misses him by more than a foot.

Sam's head is reeling, breath coming in great, sobbing gasps, and he scrambles on his hands and knees towards Dean as a frustrated shriek rends his eardrums. The shotgun is warm from Dean's skin when he pulls it free and cocks it back against his shoulder.

A handful of yards away, the troll has found itself in an old storage room half-filled with rotting hay. It flings itself against one of the walls, goes through solid wood like it's a spiderweb, and whirls around to lock in on the two humans. It screams again. In a bizarre moment of clarity, Sam notes the tendrils of grass now caught in its teeth; a vegetable side course to go with the buffet of human flesh.

This time, he only lets the troll take one bounding stride before he fires.

The buckshot does no damage to the majority of the troll's face, but one eye all but explodes, and at least two others get chunks taken out of them. Slamming to a halt, it rocks back and lets loose with a bloodcurdling wail. Now half-blind, it rocks from side to side, straining to get a lock on Sam. The thickness of its armor plates prevents it from turning its head, so the only way for it to see him clearly is if it turns so that it's not directly facing him.

Sam huffs out a breath of relief and reaches back, groping for the machete handle without taking his eyes off the troll. By the time it reorients itself, he is climbing back to his feet, blade heavy in his grip. The shotgun he leaves beside Dean. The splinters in his palm shift and dig in deeper when he clenches his fist, sending a fresh jolt of pain up that arm. The world swims around the edges as he moves away from Dean's limp form, into the relative open of what must have once been the main aisle, watching the troll watch him. It follows his movement with a careful, shuffling turn of its own. The three functioning eyes blink at him. It growls.

Finally, the thing has realized that this enemy is not to be trifled with.

"C'mon boy," Sam mutters, lips pulled back over his teeth, taunting it. "Come get me."

Obliging, it barrels forwards on three legs. Sam can hear it wheezing as it closes, and holds his own breath in anticipation. He has to move earlier this time, before the eyes close, in order to bring up the machete and aim it at the junction of head and shoulders.

For once in his life, though, Sam Winchester miscalculates.

He steps into the troll's blind spot, and, sensing a trick, it changes course to follow him. Not enough – he still misses the worst of the charge – but one bulky shoulder plows into him. Sam has the machete up to stab with, but somewhere in the confusion it is torn from his grasp, and he can't tell right away if the blade found its target.

Sam winds up on his back once more, breathless, the entire left half of his body one big scream of pain. A bellow shakes the rafters. Wincing, he rolls onto his uninjured side and lets himself curl into a loose ball while craning his neck up to assess the situation.

The troll is staggering in a circle, blind with pain and fury, roaring every few seconds in response to each wave of agony. The machete is almost exactly where it was meant to be: half-buried in the thick muscle and thin skin of the troll's neck. It's not in quite as deep as Sam would have liked, but it soon becomes clear that it has cut through more than enough. When the troll reaches up with one massive paw to tear the blade free with a sickening squelch of flesh, blood pours forth in great gouts to pool around the monster's feet.

When it screams again, the sound makes a mockery of everything that's come before, drilling straight into Sam's brain until tears form in his eyes and he claps his hands over his ears, curling his knees up to his chin and squeezing his eyes shut. There's a string of cracks and bangs in the background as the sound cuts off, several heavy footsteps, a whiff of something like a thousand butchers' trash cans left in a locked room in Texas in the middle of August, and then a ground-shaking thud.

Very, very slowly, Sam peels his eyelids open.

The troll is slumped down an arm's length away from him, head twisted sideways and mouth hanging open, blood still oozing from its eyes and neck and shoulder. In the moonlight, its skin has a pebbled sheen; a grotesque statue carved from silver, then dropped in the middle of nowhere. Sam goes to sigh in relief, then gags on the smell.

…

"Hey, Dean, you with me, man? You okay?"

No, Dean is not okay. Everything hurts. He groans, turning his face towards the sound of Sam's voice. "Feels like I just got run over by a truck."

There's a soft, huffing laugh. "Well, you did get thrown into a wall by a troll."

"Close enough," he grunts, finally getting around to opening his eyes. "Where is it?"

"The troll? There." Sam's crouched beside him, but he shuffles to the side until Dean can see past him to the monstrosity sprawled across the flood in a puddle of what he assumes is troll blood. He quirks an eyebrow. "You took that thing down by yourself?"

"Yeah." One corner of Sam's mouth curls up. "Yeah, I did."

"Damn. Didn't know you had it in you." He blinks. "Help me up?"

Nodding, Sam unfolds back to his full height, then claps Dean's upraised hand, tugging him up. His brow furrows when Dean winces. "You alright?"

"Eh." Dean waves an airy hand. "Cracked ribs. Maybe broken. Nothing major." They'll get back to the motel and wrap him up and he'll make Sam do most of the legwork for the next week or so – he'll be good as new in no time. But he pauses and takes a moment to look his brother up and down. "What about you?"

"Fine," says Sam, one hand reaching up to unconsciously brush his temple. "Hit my head in the fall, but I'm all in one piece."

"How bad?"

"Minor concussion, maybe. Nothing serious. I'm fine."

Dean frowns. "You sure? What about –"

"I'm fine, Dean." And Sam's tone ends that conversation right there.

With a shrug and a sigh, Dean drops the matter. Sam's insistent that his Satan-vision is under control? Fine. Let him keep his self-respect. He deserves some credit anyway, for taking down a troll by himself, with a concussion.

Turning away from his brother, Dean hobbles over to the corpse, giving it a careful poke with his foot. "Pretty impressive, Sammy," he says in a tone fit for discussing the weather. "Normally takes at least two hunters to bring down one of these bastards."

He can hear the rustle of Sam shrugging behind him. "It was young. And you'd shot it before I got involved."

"True." Something tugs at the edge of his perception, and he holds up a hand. "You hear that?"

Sam's expression is blank at first as he strains to hear, but the sound is getting closer, and when he recognizes it, his face clouds over instantaneously. "Sirens. Someone must have heard…" His teeth close on his bottom lip. "What should we do?"

Dean takes one look at the two-thousand-pound corpse in front of them, then turns towards the door. "Let's get out of here before they find us."

…

For all their efficiency, the Winchesters are slowed by Sam's concussion – the troll's rush hadn't helped it any, and the world spins with every step – and Dean's twisted ankle, so that Dean is only just climbing into the Impala when two cruisers come blaring out of the darkness, high beams on and lights flashing. Shots were reported in the area, they inform the Winchesters, as handcuffs are snapped around wrists.

"And with the arsenal you boys are packing in your trunk? I'm afraid we've got no choice but to take you in." The sheriff is a stocky, dark-haired man whose biceps are bigger than Sam's. He paces a circle around the Impala while his officers pat them down and confiscate the machete and shotgun, as well as Dean's demon knife, and the slim blade he carries in his boot. From Sam, they take the pistol he was carrying as a last resort in case the shotgun failed them, but miss the jackknife he'd tucked into the waistband of his jeans. It makes him feel just a tiny bit better to know it's still there, especially when they're piled into separate cars "just as a precaution" according to the sheriff. The man's smile is too friendly by far – Sam would bet that he's already logged them in as a pair of demon-worshipping psychos or something similar.

Dean winks at him just before the door closes between them, all easy, older-brother confidence. "See ya on the other side, Sammy."

…

Dean's ankle is swollen and throbbing due to the hobble from the barn to the Impala parked back on the main road a quarter of a mile away, and all he really wants from life is a cold beer, a shower, and a nap. He's not getting that, though, because the sheriff is sitting in shotgun and peppering him with questions: where he's from, what they were doing out here, why at this time of night, do they have a license for this weapon and that, are they aware of the firearms laws in this part of the country, are their names really Jack and John Smith (no relation), so on and so forth until Dean's eyes are about to get lodged in the back of his skull because he's been rolling them so much.

The sheriff is still nattering away when the deputy in the driver's seat turns off from the very-obviously-marked main road back into town, taking them instead onto a forested dirt road that seems to lead nowhere important. Dean's spine stiffens, and he sits up a little straighter.

By the time the cruiser rolls to a stop in the middle of nowhere, he's managed to close his fingers around the paperclip in his back pocket, and is fidgeting quietly, trying to slip it into the lock.

The sheriff unbuckles and twists in his seat, face splitting into something far wider and more menacing than any proper grin. "Something wrong, Dean?"

…

Sam realizes what's going on as soon as the other car's headlights vanish from behind them; when they turn off the main road, it's simply confirmation. When the car comes to a stop and the officers slide out of their seats, Sam's ready. The driver walks around to Sam's door while the man who was sitting in shotgun – if he's even a man at all – makes a show of checking the tires.

Sam twists to slam his feet against the door as soon as it clicks open, knocking the driver back onto his ass with a heavy grunt. Sam is out of the car in a flash, hands still bound behind him, and for all of a second he doesn't know whether to run or fight.

Then the uninjured officer hisses, head splitting open into the disturbingly-familiar maw of a Leviathan. He – or, rather, it – lunges at Sam with the speed of a startled horse.

Recoiling, Sam stumbles over the driver, going down in a heap, the words I'm done for flashing neon red across his brain. But somehow he rolls and finds his feet again, even as the driver's face also melts away into the visage of God's first, worst creation. It snaps at him, but he backs out of range hastily.

Run, he orders himself. Run, find Dean, get away. You can't win against odds like these. He sidesteps to put the cruiser between himself and the Leviathans. If I can just get past them…

A bellow roars through the darkness: "Sam! Sam!"

"I'm here, Dean!" He starts to circle around.

One of the Leviathans bounds forward, hitting the car and vaulting over it, and Sam takes that as his cue to run. He makes it three long strides before a heavy weight slams into his back, knocking him down; jagged teeth attempt to bite at the base of his neck, but they're thrown off by the fall, skidding down his shoulder instead, plunging through cloth and flesh in a long, agonizing stripe down his back, catching on the handcuffs… and pulling free with a shriek of torn metal.

…

"You boys have led us on a merry chase," the not-sheriff says. His partner is silent, sitting and watching, eyes gleaming. "We've been tracking you boys back n' forth across half the continent. But we knew you'd come soon enough, soon as you caught wind of the troll. And now… here you are. Good timing, too – it's been a while since I last ate."

One second, the Leviathan's yakking his ear off, the next it's all but slithering between seats, jaw disengaging, and Dean's cursing, twisting away as much as he can in the confined space. He gets one foot up, plants it on the monster's chest, and heaves it back against the windshield to buy a second of breathing room. Somewhere in there, somebody's limb brushes the button keeping the doors locked, and a snap that sounds like freedom touches Dean's ears.

He's out of the cruiser and running in the time it takes the driver to yell "shit".

"Sam!" The name rings back off trees and damp underbrush. "Sam!" If you hurt my brother, I will burn you all.

There are two sets of footsteps closing in behind him.

If you so much as touched -

his bad ankle throbs

- my baby brother –

they're faster than him

- you will die screaming –

the voice reaches him, ever-so-faint against the silent night: "I'm here, Dean!"

"I'm coming, Sammy!"

I promise.

Hands close on his arms, and Dean jerks, stumbling to his knees. They push him further, until he's face-down in the mud. His shoulders twist and bulge as he bucks back against the weight pinning him. Twists his head to the side, dirt coating his teeth, blood where he bit his tongue. His shout echoes inside his head: "Sammy!"

It trails off into a scream at the end.

…

It takes only a second for Sam gets his hands under himself after the Leviathan bites off the handcuffs, shifting his balance to throw himself upwards and knock it to the ground. Then he gives it a solid kick to the face to send it reeling, gets his arms up somehow – don't ask him how – catches the other monster's head and holds it an arm's length away when it tries to lunge at him. He twists, far harder than necessary to break the neck, and almost sighs in relief when vertebrae part and muscle rips and the head comes off in his hands.

You know you're fucked up when tearing someone's head off with your bare hands doesn't phase you. He tosses the skull away.

The other Leviathan is crawling back to its feet, but slowly, like it's drunk. Sam bends, tugs the decapitated Levi's combat knife from its sheath, and grabs the other's hair. The monster thrashes and screams as he saws away, beats at his ribs and legs until he is one big throbbing ache, but its head comes off all the same in the end. Sam is panting and weak at the knees by the time it's done. His back feels like it's on fire where he was bitten.

"Sammy!" Dean's voice twists higher as it goes, until it's all but a shriek at the end, and Sam's agonized heart starts racing again.

His legs are shaking too badly to run – when he tries, he stumbles over a tree root and plows down to land on hands and knees in the leaf litter – but he keeps up a fast jog, heart racing too too too fast in his chest, and all he can think about is getting to Dean.

They've got him.

I've let him down.

I heard him. He wasn't scared – that was flat-out, self-preservation-on-full-throttle, I'm-going-to-die terrified.

My brother is going to die.

I'm not going to get there in time.

Sam clenches his fist around the knife handle, forces a deep breath into his lungs, and surges towards the gap in the trees that he sees ahead.

…

Ripping, cutting, tearing, splitting, slicing, cracking, carving, separating, shredding, cleaving, slashing, slitting, rending, devouring.

Me.

Still alive.

They're eating me alive.

Someone stop them.

Help.

Please.

Help me.

Someone.

Stop them.

Sammy.

Make them stop.

Sammy-

…

Two hunched forms crouched over a third. A puddle spreading across the muddy road. The sounds of feasting. Sam processes this information with the cold calculation of a hunter, then descends with the fury of a mother bear.

His hands fist in the back of one Leviathan's jacket, lifting up, then flinging it away with a rush of adrenaline that makes the marrow in his bones ache. The other pulls back, mouth still gaping open. Its teeth are red with Dean's blood.

One fractured swing shears through skin and muscle but stops partway through the bones of the spine. A few jerks of the blade later, it goes the rest of the way through. The knife was made for sawing more than slashing.

The last Leviathan staggers back to its feet a few yards away. Sam straightens up to look at it. The beast appears to consider fleeing for a moment, then steps forward.

Sam crosses the distance between them in four sweeping strides, blade poised, mouth twisted, eyes glazed, and rams the knife straight through the Leviathan's spinal cord.

The head rains a trail of blood behind it when he hurls it away a few seconds later.

Sam doesn't even register the thing's last scream.

…

One of his lungs is totally gone – ripped to shreds and digested. The other is barely functional, and most of his other organs – kidneys, pancreas, prostate, liver, stomach, et cetera, et cetera – have either been ripped out or are never going to be functional again. But Dean's heart is still beating, though it slows with each passing second, and as numbness descends, he forces a hiss from his mouth.

"Sammy…"

Sam jerks around from where he'd been staring after the Leviathan's head, and is on his knees in the time it takes to blink. His hands cradle Dean's face, feel for his pulse, steadfastedly ignoring the ruin that was once his brother's abdomen. "I'm here." His face clouds. "It's okay, Dean. It's going to be okay."

"Bull." Dean wheezes and chokes on air. Sam hunches lower, eyes wide, and even Dean's dying brain cells can register the fear in them. "'s 'kay, Sammy. Get…" he coughs up a mouthful of blood that sluices down his chin, over Sam's wrist. "Get Roman fer…me…Bobby."

"Shut up – shut up. You're going to get him. You and me. We're going to hang the bastard's head from the Impala's grate like it's a cattle skull – ya hear me? You and me, Dean. Dean."

A faint smile touches Dean's lips. "You," he whispers.

"Us, Dean. Us."

"Nurgh." His heart is a dying drumbeat against the collapsed cave of his ribs. "No deals, Sammy." Sam's face seems to crumple from the inside, so Dean repeats himself to be sure: "No deals."

"Dean…"

"'Nuff. Lemme die, Sammy. Watch Baby." It takes all his energy to bring up one hand and lay it atop Sam's knee. "Watch y'self." His fingers flex. "C'mere."

A sob bursts and dies in Sam's throat. Muddy ground aside, he slips down until his body curls against and over Dean's, head nestled under Dean's, just like when they were kids. "Don't go," he pleads.

"Bitch," Dean says. His free hand tangles in Sam's hair. "Gotta go. Gotta… Sammy."

"Dean." He can feel Sam's tears trickling down and pooling in the hollow of his throat. "Don't."

"S'okay, Sammy. All okay." Dean lets his eyes close. "Promise."

"Don't go, Dean." His brother's a little kid again, six years old, scared to sleep alone. Eight, asking where Dad's gone. Seven, about to be dropped off at one of those kiddie-lands with the clowns and ball-pits. Ten, wondering about Mom. Fifteen, on his first hunt. Thirteen, getting picked on at school for his height and smarts and too-small clothes. Eighteen, leaving. Twenty-two, coming back. Twenty-seven, giving himself up for the world. Twenty-nine, watching Dean die.

If you hurt my brother, I'll kill you, I swear. I will kill you all.

"Sammy," he mumbles. "Here, Sammy."

His brother's arms lock tight around him. He doesn't let go.

…

The rest of it is just data.

At 5:52 AM, a tall young man with green eyes and brown hair staggers into the ER of Erhard, Minnesota, carry a limp body that appears to have been gutted by a wild animal. He refuses to be separated from the corpse, even after several different doctors inform him that there is absolutely nothing they can do. The fellow has been dead for hours. The man who brought him in refuses all offers of clean clothing to replace his bloodstained shirt, or attempts to tend to the ragged strip of flesh that has been torn from his back, simply clasping the corpse's hand and murmuring under his breath.

At 7:12 AM, a nurse finally thinks to ask if there's anyone who should be contacted. The young man looks up at her and says, with abrupt clarity, "Sheriff Jody Mills."

At 7:29 AM, a phone rings in Sioux Falls, South Dakota. The woman who picks it up is informed that the Erhard hospital is in possession of an unidentified corpse, and that the man who brought it in has been more or less unresponsive, but told them to contact her. The hospital staffer making the call asks if it would be possible for her to come identify the body and collect the man accompanying it.

Jody's blood runs cold in her veins. "Is it Sam and Dean?"

"I don't…the man who brought in the body has been repeating the name 'Dean', yes. Do you know him?"

"Yes. I'm on my way." Jody hangs up the phone, looks at it for a moment, then curses and throws it against the wall.

At 12:09 PM, Jody pulls up in front of the hospital and walks in.

At 2:31 PM, she walks out with Sam and Dean's body – now wrapped in a white plastic bag – in tow.

At 7:02 PM, her car grinds up her driveway and comes to a halt. Sam has not said a word for the entire ride.

At 7:22 PM, Dean Winchester's body is burned under the stars, in Jody's small garden.

"The nutrients in the ash will help the plants grow," she says.

Sam wraps his arms around himself – still in his torn and bloody shirt – and doesn't respond.

At 8:10PM, the fire has died down to ashes. Jody leaves Sam alone, figuring he needs time to grieve in solitude, and goes inside to make dinner. Sam doesn't eat.

At 10:45 PM, she goes to bed.

When she wakes up at 6:35 AM the next morning and walks outside, she finds Sam sitting cross-legged in front of the ash pile. There are dark bruises under his eyes. He accepts no coffee and no food, but makes queries after the nearest bus station. It's the first time he's spoken aloud since leaving the hospital.

"I think you should stay here until you've sorted yourself out," she tells him. His mouth thins into a bitter line, but he does not ask again.

That night, she makes him come inside and lie down on her fold-out couch. "I get it if you can't sleep, but, please, just close your eyes and try to stop thinking for a little while," she begs of him. "You need to get some rest."

When he sighs and relents, she feels like progress has been made.

…

"It's hard to watch your brother die. Believe me – I know. At least you didn't kill him." Lucifer sits at the end of the bed. Sam can't tell if he's actually being serious.

"If you're not going to help me, I'll make you go away again." Last night, he ripped off the scab on his palm because Lucifer wouldn't shut up. It feels like a thousand centuries have passed since he killed the troll, another thousand since he fell through the barn roof. If I'd just watched my step more carefully, it's possible that none of this would have happened.

"Fine, fine." Lucifer clasps his hands in his lap. "So, then… Dick Roman."

"Dick Roman," Sam agrees.

…

A week after Dean's death, Jody wakes up to find that she has been robbed and Sam has vanished. There is exactly enough money missing from her wallet to pay for bus tickets from Sioux Falls back to Erhard. A post-it note reading "sorry" in a hurried scrawl is left to replace the missing bills. At first, she is confused, until she realizes: "The Impala." Wherever Dean died… that must be where it is.

She contemplates filing a Missing Persons Report on Sam, then decides against it. The Leviathans are still everywhere. Sam doesn't need another excuse to have the authorities coming after him.

A month after Dean's death, Dick Roman is giving a speech to a crowd of twelve thousand people about acquiring one of his largest competitors when a slug from a military-grade sniper rifle bursts his skull wide open, leaving a headless stump behind. Jody watches the news report as police sweep the area. They find the assassin's approximate location at the time of the murder: atop a ten-story hotel next door to where the address was being given. Security cameras show a tall young man with green eyes and brown hair and deep lines worn into his face leaving the rooftop while carrying a large black gym back less than a minute after Dick Roman was shot.

They do not find the man himself.

Dick Roman is given a grandiose, exceedingly public, closed-casket funeral.

…

The first time Dean died, Sam went to Ruby.

Now, it's just him and Lucifer.

The Devil acts as his warning system, his therapist, his co-conspirator, his inspiration to keep going. To his credit, he never pretends that he's good enough to replace Dean.

But every day, he reminds Sam of why he can't lay down and die just yet.

Step by step, mile by mile, week by week, they track down the Leviathans.

…

As summer turns to winter and the temperature drops, the United States develops a serious case of "uncatchable serial killer". The targets are police officers, businessmen of both high and low profile, minor celebrities, religious officials of every creed, restaurant owners, farmers… the list goes on. The manner of execution is always either a hunting round that has the same effect on human skulls as a hammer does on a watermelon, or decapitation with a saw-toothed knife. After Dick Roman, all the bodies are also doused in gasoline and – for some reason that mystifies investigators – Botox, then burned. In the case of the decapitations, the heads vanish, and are never seen again.

The tall, worn young man with green eyes and brown hair becomes a face known to all Americans. Sometime around Thanksgiving, police connect the dots and reveal the killer's name as Sam Winchester. His brother, Dean, also a known psychopath, is believed dead, though both men appear to have a habit of faking their deaths as a means of going underground.

In the meantime, Jody toasts every new murder with a glass of champagne.

…

Some days, Sam doesn't think they'll ever be done.

He's getting tired.

…

They catch him on Christmas Eve. Jody watches it on live TV with some neighbors whose house she happens to be at.

The latest victim was an aging mayor whose wife came back early from shopping and found her husband being burnt in the back yard. She does the sensible thing and locks all the doors, then calls the police. The cruisers arrive in time to prevent the killer from escaping in his car, but he flees the scene on foot, and officers have to trail him through the city.

He leads them on a merry chase for well over an hour, until they finally corner him in the back alley between a Chinese restaurant and a jewelers. He watches the officers approach with wary eyes, pistol clenched tight in a two-handed grip. "I don't want to hurt you," he tells them. "You're not part of this."

One of them puts a bullet through his left elbow.

The young man who has terrified American screams and drops to his knees.

The officers rush in.

"Stop." The man rears back and presses the pistol under his chin, knuckles white. "I said stop. Back away."

The officers trade looks, still too far away to stop him. "We just want to help you, son."

A broken, half-sick, half-wild smile settles across the man's face, then slips off, too twisted to fit properly. "If only you could."

"We're going to help you. We're going to take care of you. It's okay. Put the gun down."

"Take care of me. Right. Let me tell you something." Ruined elbow held tight against his chest, the young man struggles back to his feet. "This is how you take care of people: when they want to die, you let them."

His finger closes on the trigger, his head snaps back, and Sam Winchester's brains splatter across the concrete wall.

In a living room a thousand miles away, people are cheering and applauding. In the midst of it all, Jody Miller sinks to her knees. Her friends look at her strangely. "Are you alright?" they ask her.

"I'm fine." She is staring at the television screen. Her face is blank. Not a tear trickles from her eyes. "I'm perfectly fine."

…

Dean…I'm coming.