"Anything else that has a stop-and-start behavior I could replicate in some sense might be a useful avenue to think down."

"Mm..."

He thinks. He recites some examples, in varying levels of detail. Mechanical timers; clocks and wind-up toys...

He nods. "I'm sure it can be done. May I see your drawing slate?"

"Sure."

He toys with it, delighted, for a while, then claps his hands together. "Interactions! Miles, you know how waves of water or in a rope can overlap and cancel each other? I think I can do that with magic. The switch would be a resonance frequency. Like so - " and he starts sketching.

"Ooh, yes, that's brilliant."

He wants a prototype and is clearly going to stay up until he has one. 

It's continually delightful, but Miles does have to sleep eventually. He says his farewells, goes back to his shuttle, applies all the requested typographical fixes and sends out the update, sleeps, wakes up, eats a ration bar, and emerges onto the shore.

Several people are standing there with arms crossed.

"Good morning."

"Morning. We were hoping you could help us resolve a problem."

"That's generally what I'm for. Go on."

"The rock-cutting tools that you gave our cousins are indeed very useful for cutting rocks. Except there was an accident in attempting to extract someone, and he was rather badly burned, and at that point we demanded the tools ourselves, and at that point our cousins drew them on us - "

Miles experiences a flash of deep exasperation with said cousins, rather more loudly than he intended to.

His audience looks appreciative. "Anyhow, both sides shouted their own angriest people down but there's still around forty people out there yelling at each other, we took all of the injured back here and I don't actually expect anything's gone wrong since but they're your rock-cutting tools and you're best-equipped to settle this."

"Thank you for letting me know. Can someone show me the way?"

"Yes," he says, and takes off at a run.

Miles and his power armour keep up adequately well.

It's a long trip even at an Elven running speed, though. They can't see the site of the argument until it's been several hours.

Miles spends the time organizing his mental to-do list, contemplating assorted engineering problems, and generally calming himself so that he will not greet the plasma-arc-wielders with a mental snarl of you bloody children. He is very successful!

"Miles," Celegorm says when they crest a hill and are within view. "We have two problems, one more urgent than the other."

Isn't he glad he did the hearing thing.

"Yes?"

"Firstly, there are still two people alive and trapped here and they're in a great deal of pain and it is not obvious to me how to cut them out without crushing them. Secondly is that their cries have been stressful to everyone involved and there were shoving matches for control of the plasma rays and now we are holding a few people hostage."

His exasperation is... a little more sympathetic with added context.

"As soon as I arrive to take charge of them, I am going to ask for the return of my borrowed plasma arcs," he says. "And start on solving the engineering problem. In the meantime, you can explain in more detail how this hostage situation came about."

"As soon as we've gotten out everyone who we can, you can do as you please with your plasma arcs," he says, "but we're not setting aside the possibility of rescuing these people because you want them back at once. I have no particular interest in explaining how the situation came about so you can appropriately assign guilt and threats and lectures. You can blame us for it if you wish. We rode out here to try to help get people out from the rock, and we've been doing that."