"How are you going to get precise data on when they settle if they take longer than a day or two?"

"I'd probably need to set something up with computers and sensors and stuff."

"It'd have to check a lot if it has to check by throwing things and you want really precise timing."

"It could maybe use something that throws water, or better yet, some signal that does go through gates."

"- I'm not actually sure water alone will go."

"What, really? So my infinite electricity idea won't work?"

"You have an infinite electricity idea that requires water to go through gates?"

"Yeah, one gate on top of each other and a turbine between them."

"Why does it have to be water?"

"Do you have different ideas?"

"I just don't know what a turbine is or what the water would be doing," Promise says, "so I don't know why it would have to be water."

"Oh. Right, uh..." She looks up the relevant information on her phone and shows it to her.

"Might work with gravel or something."

"Possible, I suppose, though some alterations will need to be done to ensure the gravel won't damage the turbine too badly."

"Yeah. What's the special value of infinite electricity? You've never seemed to be short of the stuff."

"Well, electricity does cost money, it's a finite resource. It's very abundant in first-world countries, but still finite and costs money."

"And one of these will solve that?"

"'Solve' is a strong word, especially given that introducing magic to the world won't be... very easy."

"Why would you have to introduce magic to the world? Can't you just give them electricity and not say where you got it?"

"Nnnnot really. I mean... To connect to an electricity grid I'd need government permission and oversight, even in countries where I would be able to found an electrical power company without being the government, and granting people power without charging for it is going to be deeply suspicious and draw lots of attention."

"Oh. How'd you make all your money with sorcery before?"

"By transmuting very rare things like precious stones and metals and selling them to disreputable buyers."

"Why disreputable ones?"

"Reputable ones tend to care about where I got the precious minerals from."

"Why does that matter?"