Jack is suddenly startled awake by his house shaking and some asshole screaming at him. So he does what any sane paranoid stab-happy psycho would do, which is to shoot a fucking knife out of his arm at whoever was unfortunate enough to be kicking the shit out of his boxhouse.

Except it's Karkat and this happens every week, so everyone should've seen this coming.

He punches the flap out of the way to glare at his stabson, who is probably bleeding everywhere now. "What the fuck do you want?!"