Better not linger in her starting place too much longer. Yellow's faster than her and may have already come home to a wreck. Thorn might have a habit of checking up on the place, even, just in case. She's invisible, inaudible, unsmellable - that won't help if he sends someone thorough. Or comes in person.
She sets out.
She's been flying for about thirty minutes after her shopping trip when she falls through a tear and squeaks inaudibly and lands in the middle of -
"If you give me a moment to make a quick map of part of the area it will affect while it's not affecting it, and then when it is, yes."
"Of course." It slows down to ordinary pendulum speed, and collapses back into the halberd shape.
"Okay, now I have a map of that square. Does it have to swing? I don't know if that will throw off my second map."
"It can be stable." It rearranges itself again, and Armsmaster holds it steady while the chain lowers the sphere.
"This is different. It's not very different, but it's different, and not in the sweeping ways this room has led me to expect of it. So that thing does affect harmonics, a little bit."
"I could probably build something to have more of that effect. Would it help if I did, or is the change in a wrong direction?"
"The important thing isn't that the harmonics be anything in particular, the important thing is that I know what I'm working with. If you think Vista's power is just spreading out the normal harmonics of this world, that makes a lot of sense; it means that under conditions where she hasn't done anything, all of the slopes are very sharp and change too rapidly for me to adjust and instantly shred sorcery in it. The optimum casting condition would be completely flat or even absent harmonics; I think the natural condition of the world must be chaotic noise."
"If that is what stops people from being able to do sorcery, this is very likely worth trying. How hard is it for humans to learn?"
"No harder than it is for fairies, I imagine, although where this gate will take me I don't know where to find a library and it might take me a while to get books."
"And how hard is it for fairies? I'm told you're immortal; we might weigh time investments differently." As he speaks, Armsmaster dismantles the piece of his halberd they tested and tinkers with the inside.
"I've lost track, but I think I'm less than a hundred years old. I started learning sorcery when I was very new. I'm pretty talented at it, but I could do simple things within a few years of work."
"What would be a reasonable amount of progress in the first few weeks? Assume ideal harmonics." He reconfigures the machinery, doesn't bother closing the casing, and turns it on. "Map the area again, please."
"With flat harmonics you could probably learn to do lights in the first few weeks, and maybe one other thing, like purifying water or warming things up." She re-maps the area.
"Or cooling things down?" He checks the sensors to tell what non-harmonics things were affected by the altered device, then rearranges it again and holds it out.
"How long before I'd be able to make a gate?"
"Gates are complicated. I'd been a sorcerer for years before I picked up the skill and it took me weeks."
"I learned healing pretty early but it's complicated and you really have to know what you're doing or nasty things can happen, which would probably be worse for a mortal than for a fairy, you could actually die doing it wrong... making yourself stronger I don't actually know how to do, but it seems doable, I could probably figure it out, but it's not common or basic."
"The cooling alone could let me fight Behemoth for that much longer, but if it's just that I'd be better off working on something else. What do combat sorcerers usually do in your world?"
"Depends on the end goal. Turn other fairies into animals, sometimes. Fire and lightning and ice. The opposite of healing is strictly speaking easier than healing, all else being equal. Occasionally rapid plant growth sees combat use."
After a few more iterations of seeing what changes the distribution of fairy lights, he feels like he has a decent grasp on what kinds of things affect harmonics. He moves on to testing the more promising ones for what kinds of changes they have.
She continues to map the square as they go, pausing once to get a new map of the unaltered region in case it has changed (it has).
Apparently unsatisfied with the pieces in his halberd, Armsmaster starts dismantling one of the less important observational equipment. He grabs a particular piece, reassembles the by now unrecognizable device, and tries it again.
"Truly flat harmonics would be amazing. If a potential liability once any other sorcerers noticed that was what was going on."