And then they can talk about ambassadorial things like trade and extradition and stuff.

Yep! Having a lot of land for the embassy will help with the Elf fondness for pretty things; it's worth delaying getting the land if it makes getting a lot of it more feasible.

How much is "a lot"?

The size of one of those fields outside the city, say, if there's something like that undeveloped somewhere. Enough space their shuttles can land and they can have a garden, nothing like the size of a city so they don't seem unfriendly.

That sounds reasonable. Does he have location requirements, because starting a construction project that size inside city limits would be complicated.

Not at all! They can get anywhere on the planet within two hours.

Convenient! It should still be somewhere relatively easy for people who cannot do that to get to, since humans can't. Or Kilaiuossari humans, anyway.

(He is blissfully ignorant of Idaia and Imliss's existence, let alone circumstances.)

"If you'll let us build a train from the city we can't quite pull off 'anywhere in the world in an hour' but we can definitely do 'across the country in that'."

"What's a train?"

"The basic idea is that you lay down rails everywhere and then trolleys can go on them, classically powered by coal they cart along with them. Then we improved on the coal, then we improved on the rails, now it will just look like a bubble flying down a sleek metal line for no reason. We can give you the old version if you'd like something you can more easily reverse-engineer but they're not as safe and not as fast."

"That I have no especial insight on, being neither an engineer nor in the department of transportation," he says, "but the concept in general seems likely to appeal."

"Trains are great."

"They sound very convenient."

"There're - a lot of things like that. We can endeavor to be minimally disruptive."

He nods, slowly.

"Assuming you're telling the truth on all counts, you're the most important thing to happen to this country in the Queen's reign."

"With all due respect you are still underestimating this. But it's very nice to meet you."

He laughs. "I imagine that no matter how momentous it is a case could still be fairly easily made that the formation of the country was more important to it," he offers.

"I'll grant you that! Are there engineers we should talk trains with?"

There are! He is not personally familiar with where they are but he can find someone who'll know.

"Thank you."

He finds someone who knows which of the engineers are in their workshops presently. The person can also show them where the relevant workshops are.

"Thanks. Is there more to cover here, or should we go meet them?"

There is some more to cover but plausibly the ambassador should talk to some other people first.

"Yes, I can imagine. Sorry for making so much work for you."

Not at all! It's fascinating work!