A storm is coming.

Dean can see it on the horizon, dark clouds rolling towards them like the smoke of a demonic possession, angry and dangerous. The air in the Impala is thick and close even with all the windows down, his baby gaping open like she's struggling to breathe in a world that's suddenly become electric.

A storm is coming, and Sam is standing in the middle of the road waiting for it.

His head's tipped back like he's going to be catching snowflakes, only this storm will bring rain and it will be hot and thick like blood.

"Get in the car, jackass!" Dean shouts out his window, and his voice is snatched and stolen by the growing current in the air. He considers getting out and dragging Sam back but he doesn't want to leave the car because even with the windows all down there's something different between in here and out there and out there is wrong.

He also doesn't think he wants to touch Sam when Sam looks like that, body taut like a cable stretched against the wind, his hands twitching at his sides as though he's seconds away from reaching out and ripping down the clouds and breaking open all the energy boiling up inside.

Lightning flashes and Sam's frame is lit up like the bones of the bodies they burn in the night. Dean feels something like fear settle deep in his chest, only fear means something else now that he's been to Hell and been devoured by it.

"If you get all wet, you're riding in the trunk!" Dean threatens, when what he really wants to say is Stop stop stop Sammy please.

The clouds are almost directly overhead now, lightning threading through the darkness like stitches in their wounds, sharp and biting, teeth in the mouths of their mistakes. The air crackles like flames and Sam is still standing in the road like this is all for his benefit and he's going to drink it in and throw it back out, like a lightning rod, inviting power and death.

Dean can remember, if he fights through the screams and the scars and the years and tries, when Sam was a little kid and storms made him jittery, anxious. They were one more thing to be afraid of then, and he would pace and fidget and flick his eyes all around until Dean scooped him up and stroked back his hair and read him a book or told him about cylinders and brake-lines.

Now Dean is hunched inside the car while Sam stands outside on a road that stretches miles and miles onward to nowhere and the storm clouds seem to gather right above his head.

Dean almost shouts again, almost puts his foot down on the gas and lurches the car forward, right into Sam's back with enough force to knock him flat, knock him away from those clouds and back into the little kid he used to be with the wide eyes and the counting one mississippi, two mississippi between every flash and thunder clap.

Then Sam is wrenching open the passenger door and sliding into the seat, his shoulders speckled with perfect circles like cigarette burns from the first of the raindrops that have just begun to fall. The lightning in the air seems to cling to Sam's skin and when he grins out the windshield at the force sweeping up from nothing Dean half expects to see bolts flicking from between his teeth and behind his eyes like serpent's tongues.

"You're such a freak," Dean manages, when what he really wants to say is There's something wrong with you and I don't think I can fix it.

Sam doesn't say anything, just keeps staring at the sky, tense and violent and perfectly still.

As Dean starts the car there's the first rumble of thunder. It rolls down the road, following them into the infinite nothing.

A storm is coming.