"This just comes back to the problem of leaving a power vacuum for whatever purpose the letter-writer had in mind."

"Waiting seems reasonable. Unless the letter arrived now because they believe the Empire is planning something imminent and wants it headed off and so would we if we knew what it was."

"Always plausible, but if that were it they could have said so. The letter claimed to be on behalf of someone who was only trying to weaken the Empire. A lie in the other direction would have been more likely."

"I didn't read the whole thing," Promise reminds her. "But yes, there would probably be a reason to be specific if they wanted me to interrupt something specific."

"We can give a week, maybe two. In the meantime, I'll look into tracking down who might have managed to put it here."

"I'll read up and try to come up with order sets that would be safe on the phone if it does come to that."

"If there's a way to do that it would be ideal, but if you think there isn't you're the one who knows how it works. Good luck."

And that seems to be that for the time being.

Faultline isn't easy to find. The rumors are that her crew is indeed taking credit for having broken into a PRT headquarters undetected, which isn't hurting their reputation. But no contacts have any leads on who hired them, or, if they're innocent and lying, who really did it.

Promise thinks about phone orders, eventually has a baseline phrasing she can spit out in a hurry that she thinks will probably work most of the time, and works on figuring out how to be transparent to Behemoth-style radiation. There's already a spell for heatlessness, in one of her library books. In flat harmonics, can she expand that...? She has a prototype working after a few days. How she's supposed to test it she is not sure, but she emails Armsmaster about it.

It turns out mortals have plenty of ways of generating radiation to test it on. It won't be at Behemoth's quantity for obvious reasons, but this Armsmaster can supply radiation in the right frequencies.

And who exactly is supposed to stand in it and see if they die?

As soon as possible. Whenever she's ready, he'll have the equipment prepared in his workshop.

She comes to his workshop and picks up a mouse and looks at it. (And pets it.)

"I have made a spell which is intended to do that and which I can in fact cast on myself. Whether it does what it's supposed to do is another matter, although being suddenly indifferent to air temperature definitely indicates that it does something. I'll need a while with this mouse before I can cast anything on it."

"I've never seen a mouse before," she comments, just in case he was hoping for really exact timing. "Even a fairy who'd been turned into a mouse. I've seen someone turned into a toad, and I've seen someone turned into a sparrow."

"So whatever happens here might be an underestimate? That's good, at least. Mice are often used for testing; toads and sparrows would take longer to find."

"Oh, people should be easier unless they deliberately try to avoid letting me have a good look at them. ...The masks might be an impediment but not a huge one, as long as whatever else they're wearing isn't completely obscuring. Someone as armored up as you would take longer."

"People being easier, even better. How long does it last if it does work?"

"It'll probably shred in any unflattened area like my invisibility did. Short of that, until I undo it."