Part 1 of the Devoured Worlds trilogy(?). Earth and other living planets have been devoured by a lichen. A fungus is used to mine planets for a mineral that makes space travel possible. The lichen consumes the fungus but also all other life. A rebel thinks one of the powerful families, the one doing the mining, is responsible for the lichen as byproduct of mining. But it turns out to be very different. Fun space opera.