Hollow Empire — J. Edward Neill

In the aftermath of a horrific plague, the people of Vhur stand on the edge of utter annihilation. Their cities lie in ruin. Their king hides in his tower. Their children rot in their graves. Surrounded by death and suffering, four survivors struggle to live their separate lives. But the lords of Vhur have different plans in mind for them. For soon must come the Night of Knives.