"And give me several hundred allied mages with access to potent unused node-energy; the agreement was that they would then help directly in my invasion. But - yes." This part, Leareth says levelly, with no sign that it bothers him. 

<All right. We will take some time to consider this.>

Leareth nods. "Do you have any further questions." 

<No.>

Leareth nods to him and Gates out. 

Matirin paces. 

It seems like Leareth is probably, overall, about as trustworthy as before, which is to say about as trustworthy as the Truth Spell. He would like to discuss the odds someone can get around  that with Vanyel or Savil but apparently they're out of commission. 

He asks Sandra. <How confident are the Heralds that a Truth Spell is impossible to falsify?>

:Until recently I'd have said nearly certain, but - I'm told I should assume Leareth is capable of a lot of things we've never imagined. Er, the only thing I can think of that'd be harder to fool is having a Thoughtsenser read him directly. I don't know that he'd agree to that: 

He nods. <Also, I would like to determine whether our methods of spying show up to your magic as anything notable.> He offers her a small pebble. 

Sandra studies it intently. Leans in closer. :...Very faintly, to mage-sight. Only from close up: 

He nods. Frowns. <Could you block that by covering it? Or...> The pebble stops showing up to mage sight. <How about now.>

Sandra leans in even closer until her nose practically touches it, searching for any sign. :No. It stopped showing up, whatever you did: Frown. :Putting it behind some rock or metal would conceal it, I think, both block mage-sight to an extent, and it would not need to block much: 

<It's off right now. We could turn it on only occasionally to minimize risk, but that would also make it less useful.> Tail swish. <That also interferes somewhat with sound quality, maybe not irretrievably... I will have my people play around with it. Thank you.>

:You're welcome. Planning to spy on Leareth?: 

<I am considering whether there is a convenient way to do so. I do not think under the current circumstances he would take it as grounds to escalate by attempting a kidnapping and I need to know more.>

Sandra nods, uncertain. :I don't know what he'd do, but - he seems to want the alliance really, really badly, so probably he wouldn't jeopardize it. I'm not a diplomat, though: 

<My guess is that if he notices he will pretend he didn't so he can feed us better lines. But much of what I'm trying to hedge against is that he's - presenting, including by fooling the truth spell, an account of who he is as a person that's quite far wrong.>

His people present Sandra with an array of new ones over the course of the next few hours. A sticky burr like the kind you might find on your ankle after walking through this forest, a tiny beetle, another rock that has a bit more stone around it.

:That makes sense as something to be worried about: 

Sandra looks at them, and runs them by Mardic, who's been keeping mostly to himself but has amazingly well-honed mage-sight because he relies on it so much in place of eyes. He can see them more reliably than she can, and they have to assume that's a lower bound on Leareth's skill. The rock with more stone around it is the most well-concealed, even Mardic can only sense anything odd if he's touching it. 

It still seems pretty risky to her to try to stick a burr anywhere on Leareth's body, even if it's turned off at first, and he comes in and out by Gate so they can't try to put it on his horse or carriage, but maybe they could arrange for one of his sentries to pick one up? It seems very likely that they're not as skilled as Leareth himself. 

The sentries are definitely a better target, though inconveniently they're also probably not going to be in rooms where interesting things are happening. The beetle can move, but that's certainly more conspicuous. They could design a rock that can roll towards wherever there's loud sound.

What if they go really really tiny, the smallest they can make a working microphone and recording chip and transmitting chip, smaller than humans can properly see with the naked eye, does that also make it harder for mage-sight to see?

It does! Sandra can no longer pick it up at all. 

Mardic can, but only because he's spent a lot of effort learning how to 'zoom in' on his mage-sight, to an even finer degree of precision than one needs for the artifact work Sandra does. He doesn't think he would ever find it by accident; he needs to know exactly where to look. 

That's encouraging. Do either of them happen to have Fetching and would Fetching it onto a sentry be conspicuous.

Mardic has Fetching! Pretty strong, and he's experienced with it. Fetching is detectable in theory, but not to ordinary mage-sight or other kinds of magic senses; it requires a particular kind of wards, and he would be able to see from a distance whether someone had that kind of ward incorporated in their shields but he's never heard of it. 

Then he will get to see what a happy Andalite tail-swish looks like; it's notably different. 

They drop Leareth a letter asking if he will agree to have a Thoughtsenser read him. They watch for a sentry to come pick the letter up.

They must be watching it, because one shows up within half a candlemark. They Fetch the letter into a box rather than approaching to pick it up, though. 

Mardic still briefly has line of sight, though, and will quickly get confirmation to go ahead, and then Fetch the teensy-tiny recorder onto the sentry.