Morty knows he shouldn't be screwing around with multidimensional shit. It's dangerous, it's impractical, it's blah blah blah. But it's a potential key to unlimited energy, how does nobody see that? He's built a dimensional siphon (it kind of looks like a cardboard box with a funnel and a TI-84 taped to it, but it damn well works), keyed in the dimensional coordinates to a random plane, and by God he's going to use it.
He flips the switch and waits for the energy bar to fill up.
It does! It fills up very rapidly. Then it explodes, along with the box. There's rather more smoke than there should be, and once the smoke clears someone is standing there.
"Oh dear," Morty says faintly.
"When people do interdimensional transit how do they locate the target world - specifically, can people find my world in particular on purpose without, well, me, or stuff that I've interacted with?"
"Not usually; it would require closer specification than would be practical to say 'the world which produced Bella Swan'. However, your world has certain distinctive features, so it would be fairly trivial to look through nearby planes for Earthlike planets with a massive caldera in place of Yellowstone."
"Planes have nearby-ness? In how many dimensions - or is it even transitive? Are nearer planes more similar?"
"To understand questions of planar nearness in any real sense, I recommend fifteen years of graduate-level metaphysics. I believe that nearer planes are generally more similar, but it's not an absolute rule. One of our 'nearest' dimensions, for instance, is an endless plain of black sand full of crystalline demons. A popular vacation spot for diabolists, I believe."
"Okay. Is looking at nearby planes usually pretty easy, do you mean literally looking at them?"
"Well enough. Now, for the lesson. The first thing to keep in mind about magic is that it is a mental task completely unlike any you have done before. It's possible to guide a student through it verbally, but there's not much reason to do that when there's an easier alternative available. What I'm going to do is the magical equivalent of taking your hands and moving them for you. It will feel very, very strange, but it should leave you with an impression of what you should do. All right?"
After a few seconds of magically doodling, Circe inserts the magic back into Bella's head. "Do you understand?"
A lesson in magic ensues! This session appears to mostly be oriented around securing Bella's comprehension of the basics of magic use- the idea of pulling Essence from within, the construction of a spell as a sort of mental sculpting, and the nature of a spell in and of itself. All very theoretical, all very fun.
Circe nods and floats a book off one of her numerous shelves. It falls open to a certain page on Bella's lap. "This is one of my preferred instruction manuals; its light incantation is simple and easily modified, and the binding looks impressive on a shelf, which never hurts. Read over the instructions and see if you can work out how to cast it without my assistance. If not, I will coach you through it. It is better to be thorough than to be quick, as mangled castings can result in hobgoblin constructs, many of which will bite you."
"...I think I would like to know more about 'hobgoblin constructs'. And their biting habits," says Bella, though she turns her eyes to the instructions.
The instructions are something like a schema for a mental sculpture. She is meant to sort of press her magic into this shape, and twist this corner like so, and et cetera. It would be almost gibberish if she hadn't been introduced to magic already, but now it seems... not quite intuitive, but sensible. As advertised, it is not complex.
Bella... reads the instructions twice, contemplates them in order in a sort of dry run, and then goes through it with live magic. It feels so cool she is doing magic eeeeeeee.
Circe smiles approvingly. "Well done. Your form could be tighter, but that is a very respectable first working. Your homework for next week will be to read appendix 1-B of that tome, 'Basic modifications', and learn two modifications of that spell. If you feel confident, you may try to come up with one of your own based on the examples given. You may wish to do all of this, especially testing your own modification, under supervision of one of your magic-using friends. Excellent work today."
"Am I borrowing this one or should I get my own copy?" inquires Bella, writing down the assignment.
"And should I be scheduling my homework with a particular view to the possibility of running out of enough Essence to cast the spell, or can I do it in a lump if that's more convenient for me or my magic spotter?"
"You should absolutely keep your reserves in mind and work in short bursts. In fact, that should be standard practice until you have been using magic for several years. Next week I will teach you how to monitor your own reserves. Until then, you may use this." She reaches into a desk drawer, pulls out a wrist monitor, and tosses it over. "When you put it on it will prick your wrist for a drop of blood to prime itself; from then on, it will display a reading of how much Essence you have in your reserve. It was the final project of a gadgeteer in the Mystic Arts program proper, a few years ago. Very handy for beginning students."