this is a really weird book. It drops you into an unknown world, into the middle of a story without any explanation. I’ve been able to glean the following: man came to this new world, which was already inhabited by sentient flying beings, who were on the verge of extincting themselves by over eating their foodstock. We were poisonous to them, but their blood gave humans longevity. So a system was setup where our dead become their food, and people “disappear” as live food. In exchange, select few humans are given the longevity treatment.
Basically at the flashpoint where the people are beginning to realize what is going on. Really hard, because there is so much new stuff that you have to extrapolate.