Inside Professor Flitwick's office.
Will sat opposite Professor Flitwick. Neither of them even touched any tea before getting straight to the point.
Beside them stood a large blackboard, densely covered with words and various magical laws. The desk was cluttered with all sorts of papers bearing Professor Flitwick's conjectures.
"Most importantly," Professor Flitwick said, pointing his wand at the blackboard, "Golpalott's Third Law. I trust I don't need to explain what that is."
Will nodded. "The antidote to a blended poison is greater than the sum of the antidotes to each individual component."
Simply put, it worked like this: if someone had been poisoned by a blend of several poisons, an antidote for that blend would require far greater complexity and potency than simply adding together the effects of the antidotes to each individual poison.
This meant that mechanically selecting an antidote for each individual component was meaningless.
One had to find an "additional ingredient" and, through an almost alchemical process, subject otherwise unrelated ingredients to complex transfiguration and fusion.
Professor Flitwick smiled. "I knew you would understand all this, Will.
"My understanding of potions may not be particularly deep, but I do have a certain degree of expertise in charms.
"So I've been considering how to derive potions from charms."
"We all know that the development of potions progressed from an initial period of accumulated experience to the establishment of theoretical foundations, and then to a systematic framework.
"Yet throughout that process, no wizard has ever converted a charm into a potion. Only a handful of people like you have converted certain potions into charms.
"Difficulty is one reason. Another is that wizards cannot control herbs as freely as they control magic.
"Potions is more of an empirical discipline with a materialist bent, unlike the more idealistic disciplines of