Drink.

"Huh.  Uh, do you want to stand in the doorway or something while I go talk to him so you know I'm not pulling anything?  - Or, I'm not very clear on Elf reasons for having to be outside; could he just come in for a bit."

"Elves need to be in pretty places. Outdoors is generally good enough and buildings not designed to their aesthetics usually are not. But he'll be fine inside for a bit, I'll ask him in." He sends a message. Alassëo opens the door a minute later.

"Hi again.  Uh, so, I figured out a thing, which is that one of the magic powers I have apparently lets me think about a situation and find out what a person would do in it?  So would it be okay with you if I tried to use that to prove your oaths were binding."

"I don't want to swear any that bind future action. It's not wise."

"That follows.  I just mean to confirm that you've been telling me the truth."

"I can give my word that things are true, yes. I'm not sure if your magic will work with only that as a demonstration, but if it will I can do it."

"Uh, I haven't used it yet so I'm not sure, but it doesn't feel like that would inherently be an issue?"

"All right. Is there anything in particular you'd like me to say?"

"Can you start by just describing the mechanics a little more concretely, so I have a better idea of what to aim for."

"I am physically incapable of saying - with respect to the use-mention distinction, anyway - that I swear something is so, like that I haven't lied to you, if I don't think it is."

"And what happens for the future actions kind?"

"If I swear I'll do something then I can't refrain. And if I swear I won't then I can't. If I manage to get into some kind of contradiction the consequences are... reported to be very bad."

She nods.  "Do you mind if I check that?  It doesn't feel like it has any effects on the real world at all, and - there are things I don't trust about this situation but so far the magic hasn't ever misrepresented how it works even when the way it works is horrible."

"It sounds fine to me."

"Thanks."

Hey magic, what happens if Alassëo is back home, where she's not watching and will never find out what happens, and - hm.  Swears to stand in one spot for six hours, and then . . . an earthquake starts up?

Well that's kind of far-off and poorly specified and contains a few big ifs, so it'll be pretty expensive with the amount of magic she's put into this skill - which is to say, none - but . . .

He stands there, but depending on how he words it might be able to inform his friends of the situation so they can physically subdue him and carry him off.

Okay.  And if - nope, okay, considering anything more feels ever so slightly aversive and it's very annoying that she only got this much out of it but she is not screwing around with that.

"Looks like it's going to take me a while to get enough to work with, here.  You can probably head back outside if you want."

"All right." Off he goes, singing prettily.

Gosh that's nice.

"Uh, guess I should probably go back upstairs?"

"If you're hoping for more time dilation it seems your best bet."

"Well, are you hoping for time dilation."

"It doesn't make much difference to me."

"Can I have some more food."

He comes up with a menu, gives her another stack of bentos.