Thinking about revenants ...
This exchange from the Professors' recent Ask Me Anything session got me thinking:
PKSchefflera
I have a question about revenants: You've said before that the wasps are just a vector for the parasites that really exert the control. Are those transmissible any other way? That is, are revenants contagious?
studiofoglio
Kaja: Not yet.
So the parasites are apparently microscopic ... bacteria? Rotifers? And yet, the parasites are capable both of controlling human minds and of obeying spoken orders from the Other (or reasonable facsimile, e.g., Agatha or Lunevka). We've also been told that animals can be revenants, and we've seen the big slaver wasp soldier forms obeying orders given by Agatha.
So ... Could they be intelligent microbes? The Professors are very familiar with the tropes of science fiction, and this is an old one. I know of one story published in Astounding Stories in the 1940s that used the idea (alas, I don't recall the title or author). It featured in the novel Slave Ship, by Frederik Pohl (1956), in William W. Stuart's story "Inside John Barth" (1960), in Greg Bear's story "Blood Music" (1983), in Larry Niven's Draco Tavern story "Smut Talk" (2000), in Joan Slonczewski's novel Brain Plague (2000), and in many, many others.
If that's what the parasites are, what's their origin? Did Lucrezia create them ... or did she find them, and if so, where?
How did Lucrezia get them to obey her? Could she have imposed her own mind upon them, as she did with Agatha?
And how do you cure a revenant? With antibiotics? By persuading or commanding the parasites to leave their hosts' bodies? By imposing a different consciousness on them with Lucrezia's mind transfer technology?