"Okay. Thanks."

"So, wait, if invisibility is working on a principle according to which having your eyes invisible means you can't see - does that mean that while invisible you can't see - or is this side effect the result of forgetting a safety that under normal not-messing-up conditions will allow you to see?"

"Actually, that's exactly what makes being invisible to cameras tricky. If it's just people, you make yourself look invisible but light will still interact with you, they just won't see you or your shadow or anything. With cameras, you've got to actually make yourself properly invisible and that comes with the caveats of needing light to interact with our eyes to see. So it's a bit more delicate, because you've still got to make sure the specific part of your eyes that needs light to pass through it is visible. If you want it to be nearly perfect then you make it so that people don't see those, either, but I don't know of a way to trick cameras perfectly."

"...So the illusion that does not fool cameras isn't a thing out in the world so much as a - mental trick. I might regret asking, but how much mental trickery is there?"

"Hmm. Some? Problem is, I don't know all magic, so I can't give you all of the specifics, but the general rule is... If you understand what's at play you can figure out you're being tricked. I don't think there's any magic to directly hijack or steal thoughts or anything, but there's probably something that could confuse you into telling them yourself."

Bella nibbles her lip, concerned.

"... Sorry. Wish I had a better answer."

"You have anything in the way of paranoid defensive magic? Do I have, like, an energy supply I need to be conservative with or is it a matter of whether I'm willing to spend the time on any given thing?"

"Luck charms you already know about. There are other objects that do different things - I know there's one that will hide you from bugbears. There might be a few others that protect you from anyone messing with your head. I don't know how to make them, though. There's no energy supply, it's a matter of time investment. I suppose I can get started on magic tutoring now, we're not in school. I'll just be honest with you and say we're probably not going to get to any actual magic for a while, I'm afraid. You've got a lot of runes to learn before we do anything."

"How many is a lot?"

"Well. Remember the chemistry analogy? It's kind of like a mix of the periodic table and the alphabet. You can get by with just some, but honestly it's better for your magical education if you eventually learn them all. I'll teach the ones you can use for invisibility first, so it's not all just - here's a rune, here's another rune, okay now prove you can draw them fifty times. Once you've got enough runes for a spell I will help you cast it. It's getting there that's the problem."

"Okay. What's the ballpark number of runes per spell?"

"Depends on the spell. The simple ones you start off with will have just four to eight or so, but around twenty tends to be typical. There's no cap for how many runes you can use, so if it's a super complicated spell you could theoretically use them all. I don't know what on earth that spell would even do, but it's certainly possible."

"This," predicts Bella, "is going to be fascinating."

Darren grins. "It really is!"

"Do you need to do runes every time for every spell?"

"Yeah. New ones, too, the spell itself will ruin the runes you draw when it's cast. You can get something that has a continuous effect that you can pull up again later, but you need runes to get that, too. Those are complicated spells, too, you can put them on people but it's safer to put it on an item, instead. That way if it fails, well a hunk of metal is disfigured, not a person."

"So if I want, like, a Ring of Gyges, that is theoretically doable?"

"Yup! Theoretically, anyway. That one would also be really complicated."

"And this would be a much better idea than casting a spell on myself that allows invisibility-whenever-I-feel-like-it, except for the part where the Ring of Gyges could be stolen and then we'd get to learn things about the effects of observation on human morality or whatever."

"Pretty much. But you can always retrieve a stolen magic ring, if something goes wrong with the casting of the spell on yourself, it's kind of... Really difficult to fix. So between the two, go with the ring of invisibility, for safety."

"How do magic items deal with persisting between forms? Same ring will not readily fit on a finger and stay put on a lion toe."

"Now you see why we don't have rings of shifting," points out Darren. "It's possible to have a ring that changes sizes when you shift - but it's easier to find other methods. A pendant that can clip to fur as well as clothes, a hair ornament, earrings - and the obvious choice of amulets. There are probably other options, too, but those are the ones I can think of off of the top of my head."

"I keep my shirt when I shift, so I guess I could work with a brooch, too. Maybe one of those expansible bracelets; I'd have to see how good sphinx wrists are at keeping stuff on. But if I have a magic object on my tail or clipped to my feathers it's just unavailable and not functioning while I'm a human, likewise if I have something on my thumb and then turn sphinx, or are you saying it falls off, or what?"