Snape repeated the process from the week before, unbinding Harry’s neck with a flick of his wand. He proceeded to peer closely at the wound, wand held aloft as he muttered an incantation under his breath. With every second that passed, his brow furrowed further, clearly dissatisfied with what he saw. Harry jumped when the potions professor suddenly pushed his seat back and stood, whipping past Harry to reach the cupboard in the corner of the room, where Harry knew Snape kept his own private collection of potion ingredients. He was just as abruptly in his seat again, a vial with a pipette stopper in one hand, and a fresh pot of the salve he had given Harry the week before in the other.