Night had fallen. In an office crowded with bottles and jars, the scent of herbs hung in the air as Will brewed an antidote.
An antidote was a substance, usually a potion, that could prevent or treat a specific illness. Sometimes it could also counteract the effects of another potion.
The magical effects of some potions wore off when their duration ended, as with Polyjuice Potion. But that was not true of every potion. Some required another potion or a spell to undo their effects, and an antidote was a more general-purpose remedy.
Brewing antidotes was required training for Aurors. Mandrake was a key ingredient in most antidotes.
This was fourth-year coursework. Snape often threatened to poison students to test their antidotes, but he rarely followed through—partly because he feared their potions might fail and someone would actually get hurt.
Tonight, he used the same threat to intimidate Will. His robes blended into the shadows, and his gaze was unfriendly. "Well, look at that. Is this an antidote brewed by our great wizard Behrens? It doesn't look quite perfect. Or perhaps you don't want to show me your exceptional skill at Potions?
"Perhaps I should poison one of your meals. Then you might find enough motivation to study ingredients and brew potions instead of spending time with someone unworthy of his position. Wouldn't you?"
"Do you mean Professor Lupin?"
"Hmph. So you agree he's unworthy of his position, Behrens." Snape gave a disdainful snort.
"..." Will stirred the potion. "There was just a small problem in Defence Against the Dark Arts, and Professor Lupin wanted to talk to me."
"Oh? Did you cast Confringo in Defence Against the Dark Arts?" Snape clearly had not heard what had happened in class. Apparently, word had not spread that afternoon.
"The Boggart I