Buffy's wet palms thrust forward at the shower stall door, not like a helpless girl, but as the slayer she was. Whatever was attacking her hadn't counted on such strength, and the binding holding the shower door closed collapsed - black smoke exploding from crevices as the door swung open. But that was only one hassle.
Whatever the smoke was, it had a plan. Reinforcing the binding of the bathroom door was it. Sam might have been able to bust the door open with a few kicks before, but not now. Buffy could have done that too, if not for the pain from whatever was on her leg. The shower steam and smoke made it hard to see. She could only feel that it hurt. When she reached down to pry it off - she could feel nothing but her own skin.
It hurt bad enough she might just start peeling her own skin off, if that's what it took.
She could hear Sam on the other side of the door, trying to break it, saying her name.
It would help if she had a clue what she was fighting, if it had an actual form.
"Sam," she said with a loud cough. "It has no real shape, I can't fight smoke." She didn't know what she needed Sam to do, but maybe he did. He was the one with all those books. If he made this smoke into a tangible form - demon, whatever it was, she could fight THAT. But it was hard to tell him that when she felt herself choking on a lack of air.
Coughing, having at some point fallen to the floor while trying to hold her leg, her wet hair was matted to her forehead as she looked at the dirty tile floor, stranded.