She starts singing.

Annie's knees buckle and she shrieks.

...she does not immediately make the connection, just shoots her a confused glance and keeps singing.

Annie doesn't stop shrieking until she's out of breath and then she gasps for it and sobs, dangling from Rirosseth's grip, unable to stand.

"What's wrong now -"

Can't answer too busy being in debilitating agony!

Probably should kill her. No, most people don't want to die even though they'd be better off. ...render her unconscious? Is that even safe to do with humans -

- the person clinging to her in debilitating agony is causing a cascade of flashbacks, she's trembling violently, she'd better - she puts a hand around Annie's neck -

- if Annie were an Elf she'd now be an unconscious Elf, she has no idea what it'll do to a mortal, she collapses on the ground and begs Melkor to make it end -

Annie passes out.

Briefly.

Bruises bloom on her neck and fade again almost at once and she wakes up and lapses at once into anguished sobbing.

Well that probably means it's not dangerous to do, she can just hold her like that -

- yup, she can keep pace with the healing.

She has everybody coordinated. She raises an eyebrow at her sister and then wearily helps her sister drag her hostage onto a horse. There are a lot of dead to sing for. They ride. They sing. 

Annie does not scream while unconscious.

It's a long ride back to Amon Ereb. They don't take it in one go, because of the children. The children are terrified and silent and wary and probably imagining that they, too, will be strangled and kept unconscious if they are difficult. She has no idea how to correct that. She sings them to sleep when it's night. They do not sleep themselves. 

Annie, quite passed out, has no comment on this.

They return home. They get the children a room. They get the children a meal. People stare at her, but only a little bit. It's been a week since she's slept. There are black spots swimming in front of her eyes. Lírnith declines to take over for keeping the hostage human unconscious, so she sits against a wall and holds her and tries to stay awake a little longer. Eventually she fails.

When Annie wakes up she is cradled in a sleeping, bloodied, fully armored mass murderer's arms and there is at least momentarily no singing within human earshot.

Annie touches her throat, catches her breath.

Assesses her surroundings.

...leans her head on the armored mass murderer's shoulder and sighs and tries to organize her thoughts.

She won't be helpful; she's sleeping. The fortress they are in has thick stone walls and this corridor is empty.

Uninterrupted downtime is actually really helpful. Annie doesn't have very many clues but she has some and she can pick through them and also her fucked-up emotional state without being in mysterious artifact torment or trying to answer the bewildering questions of Sword Lady.

Sword lady: has no bewildering questions. Occasionally whimpers in her sleep.

Poor Sword Lady.

Annie will lie here quietly for four hours or until somebody starts singing, whichever comes first.

There are people singing, but out of human earshot from here. 

Then neither she nor her mysterious artifactual torment can detect them!

She gets hungry. She starts carefully trying to extract herself from Sword Lady.

She doesn't wake.

Annie investigates the layout of the place and tries to see if any of the things she can sense are clearly recognizable even through the sense as food.

There are kitchens downstairs and recognizably-food things.