Nice chapter. Want to comment on one thing, though:
You've brought this up in several of your fictions, a common theme, I guess, that the Muggle world will eventually destroy itself. That seems less likely to me than it appears to the characters in your story (and maybe to you?). Humanity has weathered numerous major social upheavals, and I think we will survive our current problems. I don't think I'm a blind optimist; I know there are problems, and the world I see in the future is not as nice as the one I was born into, either economically or environmentally, but I don't see total societal collaps.
But then again, your (or JKRs) wizarding society is fairly blind to a lot of the "muggle" world, so it could just be a miopic view of the wizards that gives a motive to the dark lords.
Well, just wanted to get that out of my system. Otherwise, nice story. Thanks for writing it.
Tom A.
Author's response
Yes, the wizards (my Old Believers, Grindelwald, etc.) all believe the Muggles will destroy themselves, leaving the magical in charge.
Hasn't happened yet, though, has it?
So, I use that as an underlying motive, but I won't be showing it because I don't think it's likely (just possible). After all, it has happened before in various parts of the world (although not everywhere at once). And it is part of the belief systems of many.
"T"