Disclaimer: Not real, not mine, not making money from this.
A/N: The Bible that Jack holds is opened to "The Song of Solomon" in 13x02. This is an appropriation of sorts.

If she is a wall,
We will build upon her
A battlement of silver;
And if she is a door,
We will enclose her
With boards of cedar.

– Song of Solomon 8:9

A silver bullet to the heart. That's how you kill a werewolf. They're hunting one today. How simple it is, to make a werewolf die.

Dean stands at the head of the long table, three shots of whiskey from complete sobriety. He loads his gun, making gratifying little clicks. The gear is packed: two duffels side by side on the table, next to Greenland. Sam pushes his hair impatiently behind his ear and looks at his brother.

A regular werewolf turns under the full moon. It has superhuman strength and agility and is driven by its need to feed. It will, invariably, consume the heart of its victim. Its bite will infect and transform the bitten human into a werewolf like itself. By all other appearances, it will seem human. It will betray a sensitivity to silver, but apart from that it will walk on two legs, converse, engage in rational decision-making and express its desires in an appropriate fashion when not influenced by the undulations of the moon. It will display a semblance of humanity.

It has been decided that Jack will sit in the back of the car.

Dean loads the trunk. Dean drives. Sam scrolls really quickly on his phone. The tablet sleeps in Jack's lap, ignored.

Is he also a semblance of humanity? How much of him is his mother, how much the devil? Jack remembers the clean entry of blade into flesh as he plunged the knife into his chest, in and out again, like the slide of a butter knife into butter. He had tried that also and found it pleasant.

That was when Sam made breakfast, which Dean did not eat.

Dean glances up at the rear view mirror, is shocked despite himself that the boy in the back seat is not Sam. Jack has begun reading on the tablet and does not see this.

They are driving to San Francisco, California. Sam had dug up a news report of a man's body found in a dumpster with his heart ripped out. He had stared at the screen for a while before handing the laptop to Dean. Dean had looked at Sam and nodded. And now they were on their way to kill a werewolf.

Dean will kill him if he proves himself beyond saving.

Sam falls asleep. The phone slips from his fingers. Dean picks it up, tucks it back into Sam's pocket, all the while keeping one hand on the wheel. He looks up into the rear view mirror again.

This time Jack looks back at him.

They stop at Ashfork Inn and check into the only available room. Jack heads to the couch without being told. He opens the Bible again. Do not look upon me, because I am dark, because the sun has tanned me. The pizza arrives, they eat. Dean mumbles, no, no, in his sleep, and once, Cas. Sam does not close his eyes till two hours before dawn. Jack dozes as the sun rises.

Sam. Sammy. The sting of knuckles against his cheek. Wake up.

There will be a bruise by mid-morning.

The brothers trudge back to the car. Sam walks over to the driver's door but Dean brushes his hand off the handle. Seven hundred miles, ten and a half hours to go. Sam tosses the leftover pizza onto the back seat beside Jack. Slowly they exchange the flat, faceless plains for concrete and glass windows. When a light drizzle falls Jack chases the raindrops.

Hey kid, give me the–

The city is bright and bustling and very loud. Jack walks behind Sam and Dean, taking in new sights, new accents, new manners of dress. There is an immense metal bridge in the distance over a body of water that ripples delightfully. The sky is blue and cloudless.

Come on, Jack.

He doesn't have to wear a suit today because only Sam and Dean are playing FBI officers. He sits in the car as Sam lifts the yellow cordon tape and ducks beneath it. Sam distrusts cities, distrusts his own skin that he seems to slip so easily into, faux intellectual, fucking hell. Dean has never bothered pretending, content with having a gun tucked under his belt and a flask in his pocket. Sam, well. Sam just has to have his sheaves of research. Dean rolls his eyes.

They slide back into the car, slam the doors at the same time.

Werewolf, all right.

The peak of the lunar cycle's gonna last two more days, three at most.

This is so normal it's creeping me out.

Back at the motel they fast forward through the security footage but find nothing suspicious. Dean volunteers to canvass the bar. Sam runs through the victim's list of contacts for possible suspects, Jack at his elbow.

So... a werewolf attacks someone but has no memory of it in the morning?

No, not really. Well, it, he, has to be asleep in order to transform in the first place. Perhaps what he does is a little like sleepwalking, but with more dangerous consequences. Regular werewolves are different from purebloods who can transform at will and remember part of what they did under wolf form.

So a werewolf is actually a human who changes into a monster against his own wishes?

Some purebloods exploit their abilities, while others, well, others, they keep it under control, as best as they can. Our friend, Garth, he is a werewolf and a hunter.

A hunter!

Yeah. Garth lives with his pack and they eat animal hearts.

Oh.

You should meet him.

You said he lives with his pack. So the hunters leave them alone? But you also said he was a hunter–

As long as they are not a danger to humans, yeah, we pretty much leave them alone. This one, however–

He, it, killed a man.

Regular werewolves are completely under the influence of the moon. They can't control their transformation or the things they do after they transform. But usually they act out their daytime desires, which is how we catch them. We look for incidences of conflict involving the victim in the daytime, suspicious characters who display aggression, test them with silver.

Oh. But–

Yes?

They're also human, right? In the day.

No, they're werewolves. They just look human. Look, Jack–

But–

It's not–I don't expect you to understand. There was–there was this girl, Madison, who was, well, she–she became a werewolf after she was bitten by her neighbour who was infatuated with her.

Why?

He was probably acting out his repressed desire, hoping that if he turned her she would become his mate. Werewolves have a very strong pack instinct. They need community.

But that's wrong. He should have–

Asked nicely? Well, he didn't. Madison attacked her ex-boyfriend, whom she secretly resented for his domineering and possessive behaviour. She wasn't even aware that she had killed him. We tried the sire cure, but it didn't work.

Blood of the werewolf that turned her. I read that. In the book you gave me.

Yes.

Did you kill her?

Sam's phone rings.

Hey. Turns out there was some kind of fight here.

Huh. Isn't there always.

Vic pissed off the bartender. Text you the address when I get there.

Dean! Wait, Dean–damn it.

Sam grabs his jacket and leaves the room. Jack looks at the door.

The door opens again, slams shut.

Dean, I told you–

What? It was a milk run. Could've done it with my eyes closed. Did do it. Nailed the fucker.

He staggers a little.

You were supposed to wait for me.

I'm not the one who needs baby-sitting.

Dean.

Fuck off, Sam.

Fine.

They start the long drive back to the bunker at first light. Sam folds himself into the driver's seat. Dean hands him the keys.

Jack falls asleep.

Hey. Hey kid–

Jack, wake up. We're home.

Sam is glad to return to the bunker, to be back among familiar things, his books, the furniture, the steady hum of the generators. Jack runs his hands, as he always does, along the warding in the walls. He once told Sam that he could feel them.

You can?

He nods, and presses his palm onto a random spot. A bright sigil (an eye? a bird?) flares, dies down again into pale grey.

Dean burned the body. There will be no more werewolf related deaths in San Francisco for a while because what gets burned stays dead.

The mind throws itself back to some touchstone in the past. The mind provides its own occasion to which it returns, hurtling.

Jack goes back to his room. Sam follows Dean into his. He sits on the edge of Dean's bed. Dean shrugs off his jacket.

Sam's jaw tightens. It's barely perceptible, but Dean knows, the way sometimes Sam's muscles clench and knit against a cold that sweeps right through his body, teasing organs and marrow, sending his heart knocking against his ribs.

Jack listens.

I don't know why you're doing this, man.

What?

The kid. You get off on it, don't you.

What? No, I–

Having him around all the time. This place. Dean waves his arms about, futile, desperate. It's the whole Lucifer thing again, huh.

I don't–you–shut up, Dean.

What the fuck, Sam.

I said I'm not.

Fine, whatever.

Mom's dead and you're–

Dean, please.

Need is inexplicable. It shouldn't be. It should be simple, declarative. I need you. There. That wasn't so bad. Sam swings his foot lightly against the bed. Dean comes over and stands next to him, trouser leg to trouser leg. Except that didn't happen. His head is still in his hands and Dean hasn't moved at all.

I'm going to bed.

Dean.

I can't go to bed with you sitting there.

It comes and he pretends not to know what it is, this need that rends into his chest, sharp and clamouring. These are the days when he knows he cannot be fixed. Fuck, man, you don't need fixing. Dean unbuckles and pulls off his pants. Sam has his hands on his knees now, cold and sweaty. He stares at them like they belong to someone else. He has killed many things with these hands, but never the one thing that matters most. He himself is many things, muscle, bone, a collection of nerve endings, but he is not Sam. What constitutes Sam isn't clear nowadays. He doesn't know how to present himself to the world.

Don't you? Then let me teach you a lesson.

Dean fucks him hard in his mouth, deep in his throat as he sputters and whines, sobs and swallows. Sam shuts his eyes. Snot leaks from his nose and dribbles down his chin, accelerated by spit and tears. What a child he is.

Dean, Dean.

Yes. There has always been the question of consent. Sam worries that there must have been a time when he'd said yes, not overtly of course, but implied, a softening in his stance that did not go unnoticed by whoever was in charge of such things as the allotment of fate. Perhaps it was his first taste of Azazel's blood (did he enjoy it, he wonders, as an infant? was he already marked out for perversity?), or perhaps it was when he reached under the stack of research material and took that long-forbidden look at Dad's journal. Or perhaps it was the first time he sucked Dean off, eyes bright and ravenous, a little too eager to partake of sin. Under any and all of these instances he believes lies his own guilty volition. It is undeniable that some part of him was just asking for it.

Dean's fingers bite into his shoulders before curving gently upwards to caress his temple.

I am here, I am here.

Yes.

Dean.

Sometimes all you need is a reminder. This is what this is: a kindly reminder.

Jack opens his eyes.

It comes and he doesn't know what it is, these waves that crest and crash upon his chest, hardly dull, hardly at all, but when it comes he cannot abide by it.

A knock.

Sam.

Yes?

I–

Why don't you come in and sit down?

The back of Sam's neck breaks into a sweat. He smiles.

Sometimes I feel–Castiel, he trusted me. He believed in me even before I was born. And Dean says I got him killed.

You just gotta let Dean say what he wants to say sometimes.

But he's right. Castiel is dead because of me.

Cas made his own choices. We all do. He saw something in you that he felt was worth dying for.

But I don't see anything. I don't feel anything. I can't even die!

Jack.

What am I?

We are the sum of our attachments, the rising tally of the debts we can never repay. Sam, as always, catches himself searching Jack's cherubic face for cruelty, for the slow slide of a smile into a smirk. Let me help you, he thinks, I'm sure we can come up with something. We have all the time in the world, and I have patience cultivated from centuries. I will kill myself before letting you in. And I'll just bring you back. Let's start by fixing the Colt together, shall we? I could really use your help. Oh but he shouldn't, he really shouldn't. Dean was right. This is sick. Still the symmetry of it is extremely enticing, how the sins of the father are being visited upon the son. Sam laughs. The Prince of Lies spawns a boy who can only tell the truth, who is guileless enough to believe that the man who is speaking so gently to him now bears nothing but the best of intentions. And Sam, who finds it so attractive, playing bait, is willing to wait, and wait, for the first stone to be thrown.

My father, my real father. He hurt you.

Sam clears his throat.

I'm sorry, Sam.

It wasn't–It's not for you to be sorry.

But I am. I am sorry.

Just don't. Please. Sam is sick of apologies, most of all his own.

Okay.

It's not–

I–I should go.

No. It's okay. Sit. I just–I need a minute. Sorry.

Okay.

I was–Azazel–he–I was fed demon blood as a baby. Sam spreads his fingers out in a fan, turns his hand about so he can see the veins running up his wrist. I was chosen to–

Jack touches his wrist, his hand, smoothes his thumb down those long fingers. Sam holds still, fights the urge to hide, to run away. Jack looks up and asks, is it still in you? The blood?

Sam shrugs, a yes, a no, maybe.

Why are you telling me this?

I don't know.

I wish I could make everything better. I wish I could make everything right again.

I did once. That didn't go so well.

I have to.

I know. What I mean is, some histories are not for you to bear. Some things are destined and beyond your intervention, do you understand? Sam doesn't know why he is saying this. He really shouldn't be complicating matters; he should encourage the boy's fervour. They need Jack's help to get Mom back. They need the devil's son to bring back their mother whom the devil had spirited away. This twisted universe that's fucked beyond belief. He covers his face.

But you said, we make our own choices.

Yes. But–

I want to help you and Dean. I want to be good.

You are.

I wish Castiel was here.

But Sam doesn't want to forgive, oh no, not yet.

I want you to be happy.

Jack doesn't need instructional videos. He knows all this without being taught, how to take and to give pleasure, and Sam, how to be used and to be the object of derision. This is what this is: a kindly reminder. The devil's son and the devil's vessel, each making his own amends. A kiss, another, and another, and after that who's to say Sam has ever wished to make Jack suffer just to enjoy Lucifer's reaction, even if he has always tried to believe that we are nothing but our own persons, the sole executors of our own fates? And Jack, more human than most, upon knowing this, loved him all the more with that undisguised affection he brought to everything he beheld.

Midnight in the bunker. Perhaps they should all face reality with a little more equanimity. Dean, with his fingers clenched tight around a glass of scotch and sleep a hundred miles away, and Sam, with his eyes fixed on Jack's face, marvelling. Perhaps for once the Winchesters should take death at face value. Or perhaps not. Jack frowns in concentration, the universe tilts a little in their favour, and just once more their doggedness is rewarded.

Cas. Cas.

Castiel.

If the red slayer think he slays,
Or if the slain think he is slain,
They know not well the subtle ways
I keep, and pass, and turn again.

Far or forgot to me is near;
Shadow and sunlight are the same;
The vanished gods to me appear;
And one to me are shame and fame.

They reckon ill who leave me out;
When me they fly, I am the wings;
I am the doubter and the doubt,
I am the hymn the Brahmin sings.

– "Brahma" by Ralph Waldo Emerson