"I mentioned to my brother that you could make cities invisible, and he was very tempted. He wants a safe place to rebuild, away from the fighting, a place people can retreat to when the war starts to grind down their souls, a place where children might be born to our new world, and that might be the way to achieve it."
"'Make cities invisible' exaggerates, a little. I can make things look how I like; I can make the seeming follow the thing; but I assume people would find it inconvenient to consistently be invisible along with all their possessions and have to come to me every time they had a child or something broke enough to lose its spell. And the illusion equivalent of one-way glass over a settlement would still leave it looking a little different from the surroundings to an observer. If I wanted to hide a city I'd probably make it seem to have impassable obstacles all around it approached from the ground as the first line."
"I was thinking of flying south to Círdan's tonight but I won't lose much time if I stay here late; I fly slowly when asleep."
"If he thinks you're too concerned with their wellbeing what can he possibly think of me?"
"Well, I can give it a try, I suppose. Can you point him out to me from here...?"
"Thirty fucking seconds, I wouldn't begrudge anyone thirty fucking seconds," Loki mutters, but she follows his hand and flies down to the tent.
"Turukáno," she replies. "I hear you want to discuss hidden cities."
"Yes," he says. "I don't want our civilian population in a fortress that's placed for war. I want to find somewhere as defensible as I can and build a Noldorin city there, in the style of Tirion where we came from, somewhere Itarillë can grow up safely and our numbers can increase and where everyone can fall back, if they fail as we're Doomed to."
Loki nods. "Seems like a reasonable thing to do. Making the city outright invisible won't work; everything in it would have to be invisible too. Do you need it to be impossible to see or impossible to reach?"
"Oh, if you're in the mountains it'd be much easier to cover you over with something that makes it look like you're not there -" She makes a little illusion of a mountain valley. "This is nowhere in particular, I haven't been scouting for suitable mountain locations, but if you're in a dip -" She puts a little town in the dip, then roofs it in a shallower valley floor. "Like so. Does that suit what you had in mind?"
"Also, the illusion cannot react to the environment very much - I did get them so they'll catch reflected colors off neighboring things and their shadows will work right, so the grass in your fake valley will look like the sun is where it is and dim under clouds. It will not get soggy in the rain, frost in the winter, react correctly to the prevailing wind - I can make it ripple in a programmed way but not actually interact with the air like that - or accumulate snow. A more barren fake valley solves some but not all of these problems."
"More noticeable to anyone who's familiar with the skyline of the mountains, but -" She replaces the valley with a peak. "Yes, if you settle somewhere that's how the mountains tend. But clouds that go around mountains will go through an illusory one, and most mountains that are high enough to be always snow-capped are high enough for low clouds to approach them sometimes."
He nods. "Thank you. I can plan around that and determine the setup that makes the most sense for us. If you expect he'd answer honestly - perhaps you can suggest that the question comes from one of his people - you could ask Nelyafinwë how far the Enemy's scouted, and what means he has to learn the lay of the land."