"Well they have to be giving it to people somehow. Mass producing it to slip it to the entire population. Chances are the best place to find it in mass quantities is..." Su paused, crinkling her nose. "The person who is making it, or the place they're using to distribute it to the people. I'd say maybe the Ministry, for most people? But-" Suddenly her eyes lit up. "Hogwarts! They have to be giving it to students at Hogwarts, right? And presumably all around the same time... there's a lot of students. Maybe in the food? In which case they've got to have a stock of it there... possibly even in the kitchens." She paused and then shrugged. "But that's all conjecture, I mean we couldn't know for sure."
Focusing on what Kevin had suggested, she said, "Well, one would assume that without further exposure to the potion, the symptoms would eventually wear off. I doubt it could be a one-time thing, I don't think potions like that exist. But the problem is, the entire wizarding world is affected. Taking people and helping them to come off the potion could take ages. But an antidote, mass-produced in the same way the potion itself is..." Wow, her brain was really going into overdrive.
Shaking her head, Su made herself focus on them again. "How does the coin work?" Her gaze darted back to Dean. Neither she nor Kevin had been in the D.A., so she had no idea. "But Kev is right, we've no idea who is affected and who isn't. Trying to feel them out sounds like a good idea though... I bet we could use the journals for that really well, especially with the magical signature changing."