Commander Rhys Rhodes transmigrates to Da Ning, border soldier. He takes Elara Garnet, daughter of official. Fights enemies, navigates politics. Leo Sanders builds Border Market, innovates repeating crossbow. Investigates smuggling, Garnet case, exposing officials. Altan, Khan, invades south; Rhys is plotted against, trapped. Captures fortresses, maneuvers forces. Resists invasion, digging into court's network. Rises at border, awaiting final battle with Khan.