Obviously the thing to do when the trees cry out that there's something awful and wrong in Doriath is to flee. 

She doesn't do that.

Obviously the thing to do if you're not going to flee is to shoot at it. 

She doesn't even know how to draw a bow. 

She turns and looks at it and it's a snake with a mirror held in its jaws and at this point she realizes how devastated everyone will be if she's injured and she turns to flee but by this point it's too late, no matter how swift she is on her feet.

...this does not usually happen, and Bella's standard of 'usually' is pretty rigorous.

"Who are you? - Keep your voice down."

She is no longer in Doriath; she feels it instantly as the absence of a thousand other senses. She then looks around and feels it more obviously; no Elves or even Dwarves would have built such a place as this. And someone's speaking a language she's never heard, and -

She should be terrified. She is actually kind of excited. Hello.

...the fuck.

Hello. If you make a noise we will have company I don't want. Who are you? How did you get here?

The girl is alarmed; she smiles apologetically and tries toning down the osanwe. There was a snake in Doriath. I'm actually guessing it wasn't a monster of the Enemy's, random creatures sometimes make it past the wards but things of evil never would. I'm Lúthien! It's nice to meet you, I'm sorry if I've somehow trespassed...

You're going to need to back up and give me way more context. I have never heard of Doriath or the Enemy or wards.

Some people call it Eglador? Are you Avarin? You don't look like anything I've ever seen, actually - and even the Avari've heard of the Enemy -

I'm sorry. This has never happened to me and I feel numb all over from missing Doriath and why is this room so appallingly ugly I think I need a little time to collect myself.

It's a hospital, they're not meant to be decorative. That's beside the point. The point is we need to figure out how to get you back where you came from because you cannot stay here.

...why not? I mean, I should go home, people will worry, but is this place dangerous? I'm happy to help in the war, it's just my father'd never let me risk it.

I think you've gone farther than you realized somehow and this is another planet entirely, and it's going to be eaten by a monster in a month.

...oh.

Then we need to get everyone out. Probably not to my home, it can't feed them all, but to Valinor, maybe, or even in the Noldor kingdoms you wouldn't get eaten by monsters, and also I'm likelier than any of you to be fine, since you're all incarnates. Are our months the same length? What's the monster?

A month is thirty days. If you've got a way to evacuate seven billion people I'm all ears. The monster is an unusually large version of a kind called a witch.

Seven billion? I think we need the Valar.

Never heard of 'em. Look, I think I can handle the seven billion people. It's you I can't handle, you're not supposed to be here.

How are you handling the seven billion people? That way of handling should work for me too, shouldn't it?

Nope. I'm in a time loop. I get more than a month to try stuff and practice and acquire resources. You are not in the time loop. You do not normally appear in this room now.

...can you maybe start at the beginning?

This planet is being used by evil aliens - by the way, if you tell the evil aliens anything of significance I will instantly restart the time loop without you do not fuck with me on that - as a power source. The extraction process involves granting naive teenage girls wishes and giving them magical powers in exchange for their service fighting witches, generally without telling them that they'll eventually turn into witches too. I made my wish before I knew about all this but fortuitously my magic powers manipulate time; when I reset or die I wake up here a few minutes ago. You are not usually here. You need to go home.

Uh.

Okay.

I can't think of an avenue more obvious than letting this body go and heading to Mandos but if you've never heard of the Valar it might take me more than a month even to find him. I can do that if you really think it's going to be dangerous to be here. What are witches?

Ex-puella-magi who run out of witch-hunting byproducts or have emotional meltdowns turn into horrible despair monsters who cause people to commit suicide or violent crime around them; that's witches. I do not know what Mandos is. - Since astronomers have not noticed discrepancies in the movement of the stars I think I am in fact traveling back in time per se, not just resetting the planet. Something genuinely irregular happened to you; you might be from a different reality with its own time stream or something.

My reality's going to be trying really hard to find me but I don't know how that'll work with time things. Mandos is where we go if we damage our bodies beyond repair, he makes us new ones. If this is a different reality I don't know how I'd find my way there if this body died. 

I don't either. If you don't have a way home the only obvious thing I'm coming up with is convincing a potential puella magi to wish you home. Which alerts the evil aliens, but I can reset right after that before they can do anything about it.

Are you going to eventually figure out how to save the world?

Working on it. I'm trying to track down where the giant witch is earlier in the month before she's so hard to kill. And get better at killing witches. If you have any cool otherworldly resources of any kind to drop on me, wouldn't say no.

I mean, I'm half-Maia and sing like it and depending what kind of incarnate you are I'm probably physically a lot stronger than you? I can't compose a song specifically for witches in a month, though.