...

Let's think this through clearly, Illia.

Fact one: She's never heard of this place, and she did very well in her geography lessons.

Fact two: None of them are mages. She can tell. You learn to recognize another mage, after a while.

Fact three: If there were a great mage who was good enough at bloodworking to make things that were viable but still called twisted abominations...she can only beg the Sun she would have heard of it.

Fact four, and less damning than the other three, is that they still fight on horseback.

What exactly do you mean by 'twisted abominations.'

Orcs, great scaled beasts, Balrogs. He sends memories. She's panicky. Not that he blames her, exactly. Hopefully that's convincing enough. If she decides to get the other side of the story about the war and march off towards Angband he'll have to stop her and then things will get interesting.

My. Sister. Has managed to get me lost in--in a completely different universe, it looks like. Or at least another planet, or--or something!

I was guessing you're just far east of here, he says, refraining from mentioning the guess that she's an enemy. There's lands we have not charted.

This is the entire world, as my people know it. And she shows him a world map and a globe, with the implication that the former is an imperfect representation of the latter.

He raises an eyebrow. In that case, yes, you are somewhere else. Your sister is a creative person.

I sincerely doubt she did it on purpose. If she had, she would be here, or I would be wherever she is.

He nods. What exactly happened?

My sister is probably going to be a Great Mage someday. One of our teachers has philosophical objections to the existence of Great Mages. He decided to kill her to prevent that, and me so I didn't tell people it was him who had done it. She grabbed me and then--I was here. I can only assume she was trying to get us away and wasn't careful enough about where we ended up.

I'm glad you both made it out alive. What's a Great Mage?

A Great Mage is someone with the pain tolerance and mental resistance to do as much magic as they want, who's been doing it long enough that people agree they really are one.

I see.

That's a hook to ask for an explanation and perhaps demonstration if he's ever heard one, but 'Enemy scout, somehow' makes far more sense than 'interplanetary visitor' so he does not ask. 

I can send messengers inquiring after the wellbeing of your sister. It is possible she landed elsewhere in this world.

Perhaps they'll 'learn' she landed in Angband and needs rescuing; that'd be a scenario designed for his specific weaknesses.

That would be kind, but if the situation is as you describe I would hate to take resources away from where they're needed more.

Well, excuses to send messages to my cousin are arguably moving our resources in more of a strategically adviseable direction, he says lightly, and dismounts because she really does not seem likely to immediately attack.

In that case, I would be happy to accept.

Nolofinwë can hear him from here, is anxiously watching them still. My counsel is that we tell everyone - and I do think it ought to be everyone - that there's another one like this out there, and she says her sister has greater capabilities. We're going north where it's less of a disaster if I'm wrong in my judgement of her character.

I'm not sure how useful it would be to describe the workings of our machines in any case--nearly all of them require at least a little magic to use. I suppose I could see if I could teach you that, too.

We'd certainly be interested. In your world, these machines have replaced horses in war?

Yes. Horses are considerably more fragile than steel, so a contest between a man on a horse and a man in one of these is all but predestined.

Steel costs a bit more, though, and moves a bit slower.

Movement's what the magic's for. I don't know what a horse costs but steel isn't that expensive.

Here it is very expensive. Do you have magic for its production, too?

Part magic, part chemistry. Most things aren't pure magic unless they're being done by a Great Mage.

I see. They're walking rather slowly. Do you know how to ride a horse? It'll get us to our destination much faster.

Um. I've never done it before. Is it hard?