"Yeah. Plus the more normal kind of precautions like not doing unfamiliar spells on anything you care about."

"But you can't really help doing them near things you care about."

"Yeah. I've never had a spell affect anything other than the specific thing I was casting it on, though, that's what being really careful with the diagram is for."

Brenda nods.

"Anyway, thanks for showing me how to update the website."

"You're welcome!"

Her next magic research session features the space-warping diagram. What are the main meanings in it?

Space, control, size, and border.

She does the same precautionary analysis she does on her own diagrams, and when satisfied she goes ahead and makes a stamp and checks that. She goes through various recycling bins and corners of the house for various sizes of unwanted cardboard box. She reads a couple books on relativistic physics, and finds them interesting but utterly unhelpful. She checks the library for anything on the civil engineering of Avalons--the space-warping itself and why it isn't used more widely, but also things like how Avalons handle plumbing and ventilation and any accounts of an Avalon being hit by an earthquake.

Apparently no one knows how to do space-warping any more and it's getting harder to hide massive construction projects such as building houses in an expanded Avalon anyway. There have been earthquakes affecting the San Francisco Avalon that she can find out about easily but the Avalon doesn't appear to have been more affected than anything else. It's understood to be lost magic. With a lot of digging she can find someone claiming that it took a full minute to incant the space-warping for the Mexico City Avalon space in somebody's diary.

Nobody knows how to do it anymore, and yet there's supposedly a diagram for it in this textbook? Runecasting as field of study continues to be a mess. If this diagram doesn't turn out to be somehow useless, Margaret thinks, she might need to talk to someone in the Avalon government and ask how much need the broader critter community has for more Avalon space.

The claim that an incantation once took a full minute is actually heartening; the descriptions she had previously seen said "one or two sentences" and she had worried that there was a length limit. If there isn't, then a lot more detail work can get stuffed into an incantation than she previously thought. To test this, she spends a day composing some extremely flowery French, then gets out the making-things-glow diagram again, and yet another rock. The incantation she says over them is technically one sentence, but one it took her well over thirty minutes of pronunciation practice to be confident in. It goes on for a solid forty seconds about the fact that this rock should be made to glow, and adds with the last word that the color of the glowing should be purple.

And lo, a purple-glowing rock.

The purple rock is grinned at and disenchanted. And if the same monologue is rephrased into four more reasonable sentences?

That also works.

She knows from her early water temperature experiments that you can't trivially get an unlimited amount of fine control just by incanting about it, but for something like space-warping she wants all the control she can get. She enchants a bunch of different rocks to glow purple with the simple non-rambling incantation, and without specifying an exact shade. Do they end up all the same color, or is there visible variation?

(At this rate, Margaret think it's pretty likely that Brenda will finish the ring and bracelet she's working on before Margaret gets around to actually warping any space. That's fine by her; the slower she goes the more opportunities she has to think of ways things could go horribly wrong and try to head them off.)

Brenda notifies her by email a few days later that the bangle is done.

There is lots of variation in shades of purple.

Excellent! Want to bring it to game? Or I can come over tomorrow if you'd rather.

Fine control trial 1: plain-language description. If she calls in the incantation for the rock to glow pale lilac rather than purple, does this restrict the range of variation or just shift it?

I can bring it. The ring might be done by then too.

See you then!

Fine control trial 2: reading out a hexadecimal color code letter by letter.

She can get a match for her chosen color like that!

Every time? Awesome! It's weird that that's more repeatable than degrees Celsius though.

Trial 3: put an already-enchanted rock next to but not on the diagram paper and specify that the new one should match it in color.

That works!

This fine-control thing is a lot easier than she thought it was going to be! Hopefully folding space will be more like lighting up rocks than like heating and cooling water in whatever way matters.

Trial 4 is matching "the shade of purple I'm thinking of". This requires a detour to get good at really consistently visualizing a specific shade of purple.

That one doesn't work. There's just as much variance in the purple than if she didn't specify at all.

On the one hand, that means she can't skip lots of work with "do what I mean" style instructions. On the other hand, it might mean magic can't be used for hostile mindreading either. Probably for the best. 

(Also, it's really good that she has a disenchantment spell now, or she'd be drowning in glowing rocks.)

That's all the science she has time to do before game night rolls around.