Well, he can't hear them. And can't take the headphones off by himself either since his hands are chained up.

They don't reach into the cage to remove them. 

People crowd around Auda, petting her or feeling her hair or trying to feed her food. 

Suppose he drops a cage around anyone who gets close to her. He doesn't start by making them too heavy.

That works fine!

It also causes some panic!

People will attempt to drag his cage away from the feast.

He can put some heavy things in the cage to make that hard! Enjoy your collection of colorful iridium-cored bowling balls!

That will sure make the cage hard to move. 

They, instead, toss the blanket over it and try to run.

Heavy things with velcro on them can be appeared in such a way that most of them stick to the blanket and pull it down.

Then he can see these intensely bewildered fairies trying to flee their feast. Some of them are trying to drag Auda away too.

Cages for Auda-draggers!

Auda ends up with both arms held by people who are now in cages and mad about it. She goes still. If she says anything, Cam can't hear it.

The fairies who are capable of fleeing do that.

Well. Holding her arms isn't bad enough for him to do anything too drastic about it.

There's quiet while everyone waits to see if any more cages will fall from the sky.

Well, he's keeping an eye on things, but has not decided to cage people just for existing.

After a moment someone walks into view. He looks around at everything and then looks at Auda. 

He says something. The faeries let go of her. He says some more things. 

Cam still can't take off his headphones by himself.

He can place something sharp facing inward from the bars of his cage and slice this stupid gag off, though!

Then he won't be able to follow any of this conversation. 

After a while Auda walks across the room towards the faery.

"Hey, I can't hear what you're saying to get her to go over to you right now but I'm gonna be pissed off if she disappears never to be seen again or to have a haunted look on her face or anything like that!"

She jumps.

He nods.

They talk some more. Then someone walks her into one of the little doors on the sides of the tree trunk.

He walks over to Cam.

He pulls the headphones off. 

"If no one has explained to you how faeries work, I'd really appreciate it if you'd let me do that before you say anything. It might have unexpected effects. If you say something dangerous the human girl will get hurt and I can't protect her from that."

Cam is listening attentively!

"Don't tell me your name. This is most important for the first name your parents gave you, or for the first name you got some other way if your parents didn't name you, but it goes for all names to a lesser degree. Don't say things that aren't true, even illustrative stories. There's a way to do that safely but for now just don't do it. Don't break promises. If you have made any promises you should probably tell me that, first."

"I don't believe I have made any promises since encountering faeries but I'm a hundred and seventy two years old and have in that time ever said I promised something."

"I have never heard of mortals having problems that had to do with promises they met before they met faeries. 

For faeries, and people entangled with faeries, the universe punishes misconduct. Lying, breaking promises, violence against people you're indebted to. The punishment is usually immediate, but not always, and usually not lethal, unless the incident was unusually bad. It affects you and everyone who is in your debt, or vice versa, or who knows your name, or vice versa. I assume you knew some of that because you only caged the people you were angry with. But had you attacked them, everyone here would have been hit very hard, including the human girl."

"You know, if the first faery had explained things that well we would have gotten along so much better. But you're mistaken - while I did know some of that, mostly from her, I wouldn't go around dropping cages on people who were behaving fine regardless? Because why would I do that? That has nothing to do with technical debt, since I don't know enough about where it's accrued."

"Caging people you're indebted to is - well it causes a lot of problems but the universe does not parse it as an attack and so it did not cause the universe to smite us all. I'm grateful for that, even if it was entirely luck. Do you mind if I get them out now?"

"My earlier statement about being pissed off if I can't verify the human's at least loosely adequate treatment stands, otherwise I don't mind."