I just finished Sideshow by Sherri S. Tepper.

Sideshow follows Raising the Stones and Grass, ultimately tying up the fates of all the characters and species from those novels and leading to the ultimate destiny for humanity.

The plot follows on from Raising the Stones, where the fungal network known as the Hobb's Land God is spreading throughout human systems.  One group decides that it must isolate itself from the network on a distant world, in order to preserve their diversity and work on the question of human destiny.  They go so far as to have enforcers whose job is to maintain diversity and the status quo. 

The novels starts when things have started to go wrong, the world is taking a dark turn and strange creatures are showing up and interfering with the populace.

It's a good book, but not as involving as the previous two.