A plan was beginning to form in her mind as she walked around the classroom being one of Knox's house-elfs cleaning. A plan involving signs and chanting. No amount of anything could convince her that she and her classmates having to take up the slack just because the Headmistress had managed to lose the school's house-elfs (a fact that was fishy in itself). But for now, she had to keep her head down and work. She stopped at a particularly dusty bookshelf. "Scourgify." She suddendly had the urge to perform an nonvocal Aguamenti on the books there, but with her luck, the woman would be watching her. So, she clamped down on that thought. "Poliotus." There, cleaned and polished, Mistress Knox. Sarcasm intended.