Levithan Wakes by James Corey.
Here is the description from Amazon:
Two hundred years after migrating into space, mankind is in turmoil.
When a reluctant ship's captain and washed-up detective find themselves
involved in the case of a missing girl, what they discover brings our
solar system to the brink of civil war, and exposes the greatest
conspiracy in human history.
--Great stuff, great characters, great plot. Highly recommended.