Pre-series. A scene mentioned in Hell House
SPNSPN
It always escalates
Sam is washing his hair in the shower and the first thing he thinks about when it starts to come out of his head is: "Witches!"
His father dismantled a covenant not two weeks before (not wasting a moment before plunging himself in the next hunt, Sam reminds himself). They were teenage girls, Dean's classmates from their previous school (fifth one this year, Sam reminds himself again), who clearly had no idea what sort of occult powers they were medling with. They were not pleased when John Winchester showed up at their parents houses and told them all about what their little girls were doing on their slumber parties.
Dad thought that would do it.
Clearly, it didn't.
His hair is coming out of his head in chunks and he's terrified, because he knows this is only the first step. He has to find the hexbag.
"Dean! Dean! Help!"
His brother barges in the motel bathroom not three seconds later. "What, Sam? What?"
"Witches, the witches… we gotta find the hex bag", Sam puts a tower over his waist and is still covered in soap when he starts looking around the bathroom desperately.
It takes him a second to realize Dean is not helping.
Dean is not helping at all.
In fact, he's… laughing? He's laughing.
He's laughing so hard he's supporting himself at the doorframe.
Oh.
"You jerk".
Sam latches on to him, but Dean's faster.
"Oh, come on, baldy, don't be like that…"
Dean runs out the door before Sam has a chance to catch him, but it's alright, he'll get his payback.
When Dean returns, Sam is giving him the silent treatment. "Oh, come on, you're not talking to me now?"
Dean's weary, but Sam's patient. He waits four whole days, only talking to his brother the strictly necessary, until he realizes Dean's dropping his guard.
On the fifth night, Dean goes to the bathroom and leaves the Coke he's been having laying open on the nightstand. It's all the opening Sam needs.
He moves fast and silent and crushes two pills in the can before his brother comes back.
Dean is out cold in fifteen minutes. Sam rejoices.
He takes out his razorblade.
Payback.
xxxx
When John Winchester goes back to the motel after a successful hunt, he's surprised that, for once, Dean is not the first one that awakes at his entrance.
Sam jumps out of his bed, hand firm against his Taurus.
Sam jumps out of his bed, hand firm against his Taurus… and he's completely bald.
"What the hell…?"
John turns on the light.
Dean blinks groggily, forcing himself up. "Wha… huh… what?"
Dean blinks groggily, forcing himself up… and his eyebrows are missing.
John Winchester stares at his sons for a long moment, considering the best course of action.
Dean is looking at him in confusion. Sam looks mildly concerned.
"You know what… I don't wanna know."