"How did these items get made if there's no way to learn magic? Are the magicians homeschooling their children and not writing any books? How did you learn?"
"Half this stuff is antiques," says the shopkeep. "Look, asking me a dozen times isn't gonna make the answer more to your liking. I don't have Hogwarts in the basement, deal with it."
"But where do you get the stuff that isn't antique - who made the Avalon itself? - isn't anybody panicking about the medallion supply? -"
"Kid, nobody knows how to make medallions."
"But some people apparently know how to make luck charms and protection amulets!"
"I'm not going to give out my suppliers' personal information. I wouldn't do it even if you weren't annoying."
"There have to be books -"
"Does this look like a library to you?"
He opens his mouth. He closes his mouth. He says, "More harmful applications of that spell just occurred to me than I think were entirely warranted during a meal."
"...Sorry. I'm pretty sure in its current form it would not actually work on fluids inside a person?"
"Yes. Perhaps I should have said our unstoppable tide of tea, or something similar."
"Yes. It's all 'won't you sit down?' 'don't mind if I do, would you care for a spot of tea?' 'ah, how kind'."
"I know. Hardly dinner conversation. Quick, let's talk about the weather. Specifically: d'you suppose we can control the weather."
"Oooh...that might be difficult to do right. Weather in one place tugs on weather in other places, after all, and it might well be tricky to take all of the relevant factors into account."
"Yeah, I wouldn't want to accidentally cause inland hurricanes or anything. Wouldn't it be great, though, if you could bottle up a rainstorm in a flood zone and mail it to the Sahara to be released there?"
"Well, I don't know about the Sahara in particular. Deserts have their own ecologies, after all, that might well be upset by naive introduction of large amounts of water. But droughts do happen in non-desert areas."
"I don't think I was aware of that. The edges of the Sahara can have imported rainstorms, then, if we can finagle it."
May grins. "You're going to do your version of the meaning set for invisibility soon, right?"
"And then we compare them and it'll probably take hours and hours to get a diagram arranged but then, eeeeeeee." May rubs her hands together.
The curry is pretty demolished at this point. "They have mango ice cream," May recalls. "I'm not sure I have room."
"That's why I had a mango lassi with the meal. I should have warned you, I suppose."