Ancestral Machines: A Humanity's Fire novel

The Warcage is a feat of unprecedented stellar engineering: two hundred worlds harnessed to an artificial sun. Built to travel through space as a monument to peace between alien species, its voracious rulers have turned it into a nightmarish wasteland, capturing new planets for slaves and resources, then discarding the old. Now, when a verdant agri-world is pulled out of its orbit and a deal goes bad, it is up to the captain of a smuggling ship to journey into the Warcage and rescue his crew.