"Or find someone else who can do better! This doesn't seem like the kind of project best attempted alone." 

"Maybe we can start a student organization for it."

Harry chuckles. "Maybe. At any rate, even confirming my theory would take more advanced scrying magic than we have, so it's not an immediate priority - you'd want to, you know, learn how to do magic, first."

"Yeah. I'm not trying to get too far ahead of myself, I just--don't plan to give up or do anything stupid."

"Well, if you're careful and you run your theories by other mages before trying anything, I don't see anything to complain about."

"Yeah. First things first, though, we have to deal with the Sentinels before we get serious on any other project."

"Yeah. Mrs. Carson said that they're going to try to get a backer for a scouting mission, but it could take a few weeks."

"They might be able to get intelligence without the risk if they can go straight to Canada or something."

"The risk isn't the main factor, though that's good to know. The main problem is that deliberately traveling across dimensions is very difficult to accomplish; it uses up a lot of powdered mithril, which costs ten thousand dollars per ounce. Whateley's got a budget, but we'd still need help to cover that kind of expense. And if it turns out the best way to get rid of the sentinels would be a mercenary army, that's another investment. Having a backer is vital, and she needs to find one who won't take advantage of the situation - part of why she doesn't want to go to the government. Mrs. Carson does think she can get it done, but it's not a one-day problem."

"Huh."

"What's Mithril?"

"One of the more significant magical metals. It's a conduit for magic of all kinds, though there's more effective conduits for some specific fields - but you can't really go wrong with mithril. It's got a couple of other properties - it burns werewolves, for instance, and it's as strong as steel and light as aluminum - but those are secondary to its magical uses."

"There are magic metals???"

"There are! Mithril, orichalcum, bloodsteel, uh, adamantium depending on who you ask - it's not quite a metal and it's not quite magic but it's weirdly affiliated with both."

"Tell me mooooooore."

"Sure! Mithril I told you about. Orichalcum is a little stronger, a little heavier, and a lot more expensive. Magically speaking, it's basically condensed sunlight. Bloodsteel is usually created through enormous amounts of murder, but we've currently got a student who has it running through her veins, so there's kind of an ethical bloodsteel renaissance going right now; it's useful for necromancers and blood mages, who do occasionally do things that aren't nefarious. Adamantium is a compound of several different metals in a matrix of ceramic, so I don't know if it counts as metal for your purposes, but it's the most durable material that can be created by humans without using magic."

"It probably counts for some but not all of my purposes. Condensed sunlight?"

"Yeah - burns vampires, purifies some forms of magical energy like sunlight, generates light and heat indefinitely."

"Is it actually made from sunlight?"

"Sunlight is involved in its creation, yeah - not just sunlight, you need a lot of mithril and gold and some other alchemical reagents too. It's very difficult to make reliably."

"So it's less concentrated sunlight and more an alloy that has sunlight as one of its components?"

"Well, debatably - from a materials science standpoint it's closer to reinforced mithril than anything, but mystically speaking, it is sunlight, or a source of sunlight, and none of the other components stay in it. The mystical definition is the one I'm usually working with, but it makes sense you'd want the physical-world version."

"I want all the versions."

"Sensible. The Mystic Arts department has some very expensive marbles of the various materials that I can show you, too, if you can get better data that way."

"--Ooh, yes."