She gives a little bow. "I don't suppose you're a crystallographer? But yes, tie-line referencing, very hard to make it click, very useful even without what I get for doing that."

"Not a crystallographer, I'm actually from a different universe and arrived last week. Also I just found out I might not be able to return at all." He shakes his head. "Anyway, what's tie-line referencing?"

She explains! Basically, a complicated way to make magic able to identify specific locations by declaring them with a set of coordinates relative to where the caster is right now.

"That's awesome! You invented that?"

"Indeed."

"Congratulations! I want to become a Fate, eventually, too."

"Work hard. Immerse yourself in magic."

"—you know, since you're a Fate and are deigning to speak to a mere immortal like me, could I... ask questions about it?"

"There is not much to tell. It's inexplicable- Though, I could sort of tell when I had the correct idea and it was just a matter of hard work and refining."

"How could you tell?"

"I knew. I just knew."

"And did you notice at the time that this knowing was correct or was it only obvious in hindsight?"

"...Your grammar is atrocious. I did not understand that."

"Sorry, I learnt this language last week. Er, I meant, when you 'just knew,' was it... clear that this knowledge was true, at the time? Or was it a feeling you only came to recognise for what it was after you succeeded at becoming a Fate?"

"Actually, I don't remember. This was... Sixty two years ago. And my memory is not far improved from a human's."

"Hmm... And do you know if it needs to be new magic? Could a sufficiently game-changing nonmagical invention do it?"

"No. It definitely needs to be new magic."

"Hmmm... And what's the... process of inventing new magic like, exactly?"

"You study magic in your chosen field very carefully, and find the worst hole, and think really hard about the best way to patch that hole."

She's flying to the next tile-spot now.

"But I mean... hmm... What do you think about, specifically? Like what kind of thing would patch that hole, what kind of effect, or...?"

"I can't explain it. This was decades ago. You're starting to get irritating."

"So should I just stop asking questions?"

"You should stop asking about things I have repeatedly said I don't remember."

"You didn't say it repeatedly, you said it exactly once before, and I don't know in advance which things you remember and which you don't."

"Well, you hit a nerve. Many people ask the same things. I'm done talking about it."