How are the floating cities in Ashyn held aloft?
By local magic... So basically, I can tell you how it works, because I'm not saving any secrets here.
One of the diseases gives this power. The reason it's called The Silence Divine is right now, the way I've devised it, is this power also causes hearing loss. So you have this virus that does this weird thing, but also gives you the power. And so there's a conclave of them, a chorus of them that keep the cities aloft. And that's why the book, if or when I write it, I guess it can't be a virus in this case. Whatever disease they have, someone develops penicillin and can potentially cause the city to come crashing down. That was the premise for me, but that means it needs to be a bacteria, not a virus but it needs to be a bacteria that stays with you long, so I have to work out exactly how I would make these diseases work.