Interdependency: Collapsing Empire (Winner of the 2018 Locus Award for SF ; finalist for the 2018 Hugo Award)

Does the biggest threat lie within? In the far future, humanity has left Earth to create a glorious empire. Now this interstellar network of worlds faces disaster - but can three individuals save their people? The empire's outposts are utterly dependent on each other for resources, a safeguard against war, and a way its rulers can exert control. This relies on extra-dimensional pathways between the stars, connecting worlds. But 'The Flow' is changing course, which could plunge every colony into fatal isolation. A scientist will risk his life to inform the empire's ruler. A scion of a Merchant House stumbles upon conspirators seeking power. And the new Empress of the Interdependency must battle lies, rebellion and treason. Yet as they work to save a civilization on the brink of collapse, others have very different plans ...

The Collapsing Empire is an exciting space opera from John Scalzi.