She falls asleep on his shoulder.

They learn what happens when you kill a Balrog, pay a dozen lives for the information. They drive the Enemy off. They bury the dead. They rebuild the walls. They sing for a week. 

He needs a good anaesthetic song so that Kat won't be hurting. He cuts a lock of hair very very short because it's the most convenient way to be able to hurt himself at will without injuries that'd require healing. He works on the song. He get something. He tries it on Kat.

Kat reacts like when he sings anything else, with mild short-term interest.

He works on it some more. He eats if brought food and sleeps if Kat is sleeping and it's been a couple of weeks. Maitimo stops by occasionally, looks in on him thoughtfully, leaves him to it. Presumably he has already figured out how to use this. That's fine. That's good, really. It's good they have Maitimo back. He comes up with another song.

- Kat pays attention to that one. She's fussy after he stops, the way she gets if she's pointing at something and nobody has given it to her yet.

Then he won't stop much. He can sleep strictly less than her - unless it wearing off in her sleep hurts -

She stirs; doesn't wake.

He can sleep strictly less than her. He gets the older orc kids, sings it for them.

They find it confusing, and have mixed opinions on whether they want to keep listening to it. One of them tries to sing it and gets most of the notes wrong.

If they want to keep listening he'll be over here, singing it all the time. 

Some of them hang around him a lot.

Their choice. Kat's, once she's old enough to make up her mind. 

 - all right, that's quite enough. He assigns three people duties singing orc-anaethesia all the time, waits for them to pick up the song well enough, goes and finds Macalaurë and the orcs and announces that these are the people who'll be providing this service from now on. 

"I need a way to kill Balrogs at range."

"Music's not good at range."

"Why not?"

" - it just isn't. Effects are local."

"You can build in exceptions for audience -"

"I could probably build in exceptions to area affected, but I can't make it stronger at a distance, has to be audible."

"Then work with Curvo on remote production of sound."

"Are you trying to inspire me to come up with a workable idea by proposing ones that are unworkable and terrible until I do -"

"Yep. Good job."

"She trusted me."

"I don't think so. She liked you. She didn't think we were good at our jobs or anything."