There's a big cast in Kingdom of the Hill Country, but the central characters are Helen Black, a young woman who has a herd of horses to sell, and James Fuller, the son of Austin's mayor and most powerful citizen. There are problems aplenty. Besides the outlaws, Houston is trying to expand its already wide borders and take over Austin, which needs fuel to run some of the old vehicles still in working order. Houston has fuel, but Austin prefers independence. There's also a character who can see the future but do nothing to change it. His enigmatic predictions play a part in things, too.
There's a lot of action in the novel, with captures, escapes, and pursuits. There's death and destruction aplenty, too. Not everyone survives. Melton juggles the plot elements like an expert and brings everything to a satisfactory conclusion, though there are many characters readers will want to know more about. Future books in the series will likely bring them back for encore performances.
Melton has another winner here, and it should make new fans for the Project Saga, with a lot of great stories yet to come.